From lasner@sunSITE.unc.edu Thu Aug  4 22:01:36 EDT 1994
Article: 977 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!sunSITE!lasner
From: lasner@sunSITE.unc.edu (Charles Lasner)
Newsgroups: alt.sys.pdp8
Subject: Re: Archive files newly arrived
Date: 31 Jul 1994 10:41:16 GMT
Organization: University of North Carolina, Chapel Hill
Lines: 75
Message-ID: <31fv4c$fgv@bigblue.oit.unc.edu>
References: <3189mi$o4q@bigblue.oit.unc.edu> <31cifb$cut@st-james.comp.vuw.ac.nz>
NNTP-Posting-Host: calzone.oit.unc.edu

In article <31cifb$cut@st-james.comp.vuw.ac.nz>,  <don@zl2tnm.gen.nz> wrote:
>
>OK, so if I have a machine with an RX50 drive (ie on an RQDX3 on a uVAX II)
>that I can do block-for-block copies to, are these images any use to me?

At least indirectly.

The problem with teledisk format is that it's proprietary.  IF you could 
figure out every nuance of the file format, you could recover the RX50 
data, etc.

However, teledisk format is far too complicated for this to be of any 
practical value, etc.  It's used currently because hardware-qualifying 
PC's can be used to format media and create copies of RX50's.  The 
program is readily available to these machines, albeit associated with a 
licensing problem, etc.  In the future, a more open format will be used 
that encourages interchange, etc.

DECmates, as well as most of DEC's systems with RX50's, cannot format
media, thus the PC is a reasonable place to turn to format diskettes. 
There are numerous programs that can do it to at least a minimally viable
extent.  (However, there are no current programs that do *all* of what
would be desirable!  Unlike the -11 and VAX world, all of the other
machines that use RX50 could benefit from alternate format options
regarding stagger and interleave.  The DECmate probably has the largest
number of desirable variants that are system-specific, but even the
Rainbow can benefit from some format variations.  The -11 and VAX world
can be congratulated for being the most consistent.  All major systems
there use the same software mapping of presumed standard media, thus there
is no need for variants, etc.)

So, if you want a PC channel to distribute your uVAX floppy RX50 images 
as binary files of the entire media, teledisk is a viable choice.  For 
the present, this is what the DECmate group has done.

In the future, the DECmate will be using a format that it can handle 
itself under OS/278.  To avoid writing pragmatic and redundant utilities, 
such a program has to wait until a more fundamental problem is solved, 
namely the ability to do raw reads and writes through OS/278 handler calls.

Present OS/278 restrictions are that handlers can only access tracks 01 
onward on a diskette, and additionally, each sector involved in a 
transfer is read in 12-bit mode, which means that only 3/4 of the data is 
accessible.  This is fine if all you want to access is the non-bootable 
file data area of an OS/278 non-system floppy.

But to create a DECmate bootable diskette requires 100% of the data in 
every sector, including sectors 1-10 on tracks 0, 78, 79.  Diskettes 
"alien" to the DECmate will tend to have other usage of these same 
tracks, and you dare not leave them out of a claimed copy of a diskette, etc.

Current OS/278 has only kludgy limited ability to access the rest of the 
diskette data, consisting of internal routines in a few programs, none of 
which provide user access to anything resembling a generic call, etc.  
(In essence, a few programs have internal subroutines used as required.  
Quality of I/O handling varies widely, etc.)

There is a solution to this problem which has been discussed elsewhere, 
namely to allow OS/278 to access P?S/8-written handlers, which include a 
handler being developed for complete access to RX50.  Using an approach 
some people know as a "TSR" it is possible for OS/278 to get "help-out" 
RX50 support from P?S/8 handlers

Once this is accomplished, RX50 files wihtout restrictions can be 
generated using a variety of methods on DECmate hardware.  The principal 
candidate currently is PDP-8 ENCODE format which is documented in the 
Kermit-12 distribution.  Other machines should be able to support ENCODE 
decoders/encoders allowing this to become a more general method of 
interchange, etc.

Got any volunteers to write ENCODE utilities for other machines (VAX, PC, 
etc.)?

cjl


From don@rata.vuw.ac.nz Thu Aug  4 22:02:07 EDT 1994
Article: 978 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!news-feed-1.peachnet.edu!gatech!howland.reston.ans.net!pipex!sunic!trane.uninett.no!eunet.no!nuug!EU.net!uunet!comp.vuw.ac.nz!rata.vuw.ac.nz!don
From: don@rata.vuw.ac.nz (Don Stokes)
Newsgroups: alt.sys.pdp8
Subject: Re: Archive files newly arrived
Date: 1 Aug 1994 11:21:55 GMT
Organization: Victoria University of Wellington
Lines: 21
Message-ID: <31ilsj$c7a@st-james.comp.vuw.ac.nz>
References: <3189mi$o4q@bigblue.oit.unc.edu> <31cifb$cut@st-james.comp.vuw.ac.nz> <31fv4c$fgv@bigblue.oit.unc.edu>
NNTP-Posting-Host: rata.vuw.ac.nz

Charles Lasner <lasner@sunSITE.unc.edu> wrote:
>>OK, so if I have a machine with an RX50 drive (ie on an RQDX3 on a uVAX II)
>>that I can do block-for-block copies to, are these images any use to me?
>
>At least indirectly.
>
>The problem with teledisk format is that it's proprietary.  IF you could 
>figure out every nuance of the file format, you could recover the RX50 
>data, etc.

So is there any chance of just getting the raw disk image in ZIP or whatever
format so that those of us who can do a bit-for-bit copy onto a real RX50
can use it without having to futz around with that brand-M bootstrap and
a commercial package that I don't want or need?

How about disk images of the DECmate backup format for thems of us with
hard disk DECmates?

-- 
Don Stokes, Network Manager, Victoria University of Wellington, New Zealand.
don@vuw.ac.nz(work) don@zl2tnm.gen.nz(home) +64 4 495-5052 Fax+64 4 471-5386


From geneb@gemstar.gemstar.com Thu Aug  4 22:02:18 EDT 1994
Article: 979 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!news-feed-1.peachnet.edu!news.duke.edu!godot.cc.duq.edu!ddsw1!redstone.interpath.net!news.sprintlink.net!nwnexus!gemstar!gemstar!gemstar
From: geneb@gemstar.gemstar.com (Gene Buckle)
Newsgroups: alt.sys.pdp8
Subject: looking for 11/23 and 11/73 software
Date: 1 Aug 1994 20:56:28 -0700
Organization: GemStar Information Services 206-539-1257
Lines: 8
Message-ID: <31kg5c$s1v@gemstar.gemstar.com>
NNTP-Posting-Host: localhost.gemstar.com
X-Newsreader: TIN [version 1.2 PL2]

If anyone could please direct me to a place to obtain software for the
pdp 11/23 and /73 I'd much appriciate it.  Any info on LSI-11 assembly
would help as well.  

thx.

Gene - KC7AFE


From hermit@cats.UCSC.EDU Fri Aug  5 12:49:02 EDT 1994
Article: 980 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!news-feed-1.peachnet.edu!gatech!howland.reston.ans.net!agate!darkstar.UCSC.EDU!darkstar.ucsc.edu!hermit
From: hermit@cats.UCSC.EDU (William R. Ward)
Newsgroups: alt.sys.pdp8
Subject: PDP8 on a chip?
Date: 05 Aug 1994 04:30:59 GMT
Organization: Computing and Telecommunications Services, UCSC
Lines: 14
Distribution: world
Message-ID: <HERMIT.94Aug4213059@am.ucsc.edu>
NNTP-Posting-Host: am.ucsc.edu


Does anyone out there know where we can get a PDP8-on-a-chip?  Anyone
ever heard of such a beast?  Supposedly this is made by Intersil, part
#IM6100; or Harris HM6100-2, HM6100A, or HM6100C-9.  Anyone who knows
about this, please drop me a line!

--Bill.

--
William R Ward                       __o __o   1803 Mission St. #339
Bay View Software and Consulting   _-\<,-\<,_  Santa Cruz CA 95060 USA
Voicemail +1 408/479-4072         (_)/---/ (_) hermit@cats.ucsc.edu
Call my tree-structured BBS: +1 408/457-1357 (300-2400 baud, MNP/5, 8/N/1)
(Finger hermit@ucscb.ucsc.edu for PGP public key)


From tomk@csd.uu.se Fri Aug  5 12:50:28 EDT 1994
Article: 981 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!news-feed-1.peachnet.edu!news.duke.edu!MathWorks.Com!europa.eng.gtefsd.com!howland.reston.ans.net!EU.net!sunic!columba.udac.uu.se!news.uu.se!tomk
From: tomk@csd.uu.se (Tom Karlsson)
Newsgroups: alt.sys.pdp8
Subject: OMNIBUS signals for semiconductor memory
Followup-To: alt.sys.pdp8
Date: 05 Aug 1994 12:06:09 GMT
Organization: CS, University of Uppsala, Sweden
Lines: 33
Distribution: world
Message-ID: <TOMK.94Aug5140610@kobra.csd.uu.se>
NNTP-Posting-Host: kobra.csd.uu.se


I'm constructing a 32K single board semiconductor memory for my PDP-8/m
(including a 100Hz real time clock), but I'm not sure of really how to
use the memory control signals from the OMNIBUS.
I've read the descriptions in the 'PDP-8/a miniprocessor handbook' and
the 'PDP-8/e,/f,/m small computer handbook' and have come to the conclusion
that I need the following signals:

EMA0-2, MA0-11, MD0-11, +5V, GND, ROM ADDRESS:  These signals are no
problem to me - they are used just as one could imagine :-)
EMA and MA for the 15 bit address, MD for data, +5V and GND for power and
the ROM ADDRESS for disablement when ROM memory is used in conjunction
with the read/write memory.
However, MEMORY WRITE, MD DIR and SOURCE or RETURN are the ones that I would
need a better description of (what their timing looks like).

Can I use SOURCE or RETURN as a memory select signal during both read and
write ?

Can I use MEMORY WRITE for the read/write signal or must I combine it with
MD DIR in some manner ?

A simple timing diagram would suffice...

Thanks!

/Tom
--
|  Tom Karlsson    E-mail: tomk@Student.DoCS.UU.SE   phone: +46 18 260097  |
|  Student of Computer Science @ Uppsala University, Sweden.               |
|  Secretary of Update.  E-mail: tomk@Update.UU.SE                         |
|  WWW:  http://www.update.uu.se/~tomk/                                    |
|           "Intelligence is to do stupid things in a smart way"           |


From jones@pyrite.cs.uiowa.edu Fri Aug  5 12:52:28 EDT 1994
Article: 982 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!news.duke.edu!zombie.ncsc.mil!MathWorks.Com!europa.eng.gtefsd.com!howland.reston.ans.net!math.ohio-state.edu!hobbes.physics.uiowa.edu!news.uiowa.edu!news
From: jones@pyrite.cs.uiowa.edu (Douglas W. Jones,201H MLH,3193350740,3193382879)
Newsgroups: alt.sys.pdp8
Subject: Re: PDP8 on a chip?
Date: 5 Aug 1994 14:56:16 GMT
Organization: University of Iowa, Iowa City, IA, USA
Lines: 22
Distribution: world
Message-ID: <31tjug$pb0@nexus.uiowa.edu>
References: <HERMIT.94Aug4213059@am.ucsc.edu>
NNTP-Posting-Host: pyrite.cs.uiowa.edu

From article <HERMIT.94Aug4213059@am.ucsc.edu>,
by hermit@cats.UCSC.EDU (William R. Ward):
> 
> Does anyone out there know where we can get a PDP8-on-a-chip?  Anyone
> ever heard of such a beast?

Well, the IM6100 was the predecessor of the Harris 6120 chip, and that
chip was used by DEC in large quantities, both for their series of
DECmate machine (sold mostly for word processing) and as a peripheral
controller for other DEC machines.

It's all in the FAQ, to be posted on the 8th, or you can get it from any
of the following archive sites:

  ftp://rtfm.mit.edu/pub/usenet/alt.sys.pdp8
  ftp://ftp.uu.net/usenet/news.answers/dec-faq
  ftp://src.doc.ic.ac.uk:/pub/usenet/news.answers/alt.sys.pdp8
  ftp://sunsite.unc.edu/pub/academic/computer-science/history/pdp-8/docs
  http://www.cis.ohio-state.edu/hypertext/faq/usenet/dec-faq/top.html

				Doug Jones
				jones@cs.uiowa.edu


From lasner@sunSITE.unc.edu Fri Aug  5 13:34:29 EDT 1994
Article: 983 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!sunSITE!lasner
From: lasner@sunSITE.unc.edu (Charles Lasner)
Newsgroups: alt.sys.pdp8
Subject: Re: Archive files newly arrived
Date: 5 Aug 1994 17:33:50 GMT
Organization: University of North Carolina, Chapel Hill
Lines: 94
Message-ID: <31tt5u$g0g@bigblue.oit.unc.edu>
References: <3189mi$o4q@bigblue.oit.unc.edu> <31cifb$cut@st-james.comp.vuw.ac.nz> <31fv4c$fgv@bigblue.oit.unc.edu> <31ilsj$c7a@st-james.comp.vuw.ac.nz>
NNTP-Posting-Host: calzone.oit.unc.edu

In article <31ilsj$c7a@st-james.comp.vuw.ac.nz>,
Don Stokes <don@rata.vuw.ac.nz> wrote:
>Charles Lasner <lasner@sunSITE.unc.edu> wrote:
>>>OK, so if I have a machine with an RX50 drive (ie on an RQDX3 on a uVAX II)
>>>that I can do block-for-block copies to, are these images any use to me?
>>
>>At least indirectly.
>>
>>The problem with teledisk format is that it's proprietary.  IF you could 
>>figure out every nuance of the file format, you could recover the RX50 
>>data, etc.
>
>So is there any chance of just getting the raw disk image in ZIP or whatever
>format so that those of us who can do a bit-for-bit copy onto a real RX50
>can use it without having to futz around with that brand-M bootstrap and
>a commercial package that I don't want or need?
>
There are several efforts in this direction.  teledisk represents a poor 
choice due to all of its "baggage" etc. but it does exist.

One such effort involves creating (on a PC) a format that is just about 
what you want.  The file starts with a header block that describes the 
disk geometry.  The rest of the file is the raw 8-bit data in the normal 
order of the disk.  Thus, in the RX50 case it would be the 800 sectors of 
the RX50 in the order track 0 sectors 1,2,3,4,5,6,7,8,9,10 then track 1, 
etc.  RX50 would be a normal case, but it's not geared specifically to it.

Note that this effort includes no form of compression, which admittedly 
is easier to deal with for your purposes.

but since storage is a concern for an archive, files should be 
compressed, or should be self-compressing.  PDP-8 ENCODE format is a good 
step in that direction.  I would like to see others implement encoders 
and decoders of it for other machines, etc.  Eventually the DECmate 
version will be viable; the PDP-8 version is currently.

>How about disk images of the DECmate backup format for thems of us with
>hard disk DECmates?

Not a bad idea.  However, there is a problem: you have to specify a 
volume size for the backup set.  Do you want volumes created that barely 
serve as the data itself, or do you want volumes created with loads of 
empty space past the data that represents someone's notion of a good size 
for a volume?  Additionally, there is the whole question of whether the 
data is also a bootable volume since invariably the data is in the format 
of some specific OS such as OS/278, COS, WPS, CP/M-80, MS-DOS, etc.

Consider a small example:

There is a program now available on sunsite called GTE that makes the 
DECmates II and up into a VT-240/241 if you have the relevant graphics 
hardware and optional color monitor.  Even without the extra hardware, 
you still get a good VT-220 emulator with a whole lot less bugs than the 
slushware terminal emulator, etc.

Consider all of the possibilities for archiving:

1)	It's already there in a .zip of a teledisk file of the 
release/install disk.  The user has to put the program up and deal with 
it, etc.

2)	Someone could install it and thus there is a hard disk volume or 
diskette copy.  We could archive the bootable diskette, but it's not 
worth it because it's so easy to create one from the install diskette, 
except perhaps on (your!) DECmate III+.  However, a hard disk volume 
version can be created on either a DECmate II w/HD or on the DM III+.  
You could archive a backup copy of that volume.

However, it turns out that this is not necessarily the best choice.  The 
program can be transferred directly to an exiting OS/278 system and run 
with "R GTE" because in reality, the bootable volume or diskette is 
really a self-starting OS/278 stripdown system, etc.

Additionally, the install program creates GTE on a volume slightly too 
large, thus disk space gets wasted.  A knowledgeable user can create 
their own custom size volume with OS/278 on it, then move GTE.SV there 
and do it themselves as a minimal size application, etc.

So, which of the several forms the above suggest would you want to be in 
the archive?  Note that the average user can navigate through the 
provided install diskette now archived, etc.  The results are likely 
acceptable to all but sophisticated users, etc.

Other programs will tend to suggest even more complicated 
configurations.  I'm open to any reasonable solution.

>
>-- 
>Don Stokes, Network Manager, Victoria University of Wellington, New Zealand.
>don@vuw.ac.nz(work) don@zl2tnm.gen.nz(home) +64 4 495-5052 Fax+64 4 471-5386

cjl


From jatwood@netcom.com Mon Aug  8 15:20:27 EDT 1994
Article: 984 of alt.sys.pdp8
Newsgroups: alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!news-feed-1.peachnet.edu!gatech!howland.reston.ans.net!agate!darkstar.UCSC.EDU!news.hal.COM!decwrl!netcomsv!netcom.com!jatwood
From: jatwood@netcom.com (John Atwood)
Subject: WT/78, RX02, DecWriter IV Available
Message-ID: <jatwoodCu698r.E70@netcom.com>
Organization: NETCOM On-line Communication Services (408 261-4700 guest)
Distribution: usa
Date: Sun, 7 Aug 1994 15:48:26 GMT
Lines: 44

I have the following DEC equipment available:
  VT/78-MA Desktop PDP-8
  RX-02 Dual 8" Floppy Drive
  DecWriter IV
  two sets of boot floppies

From the pdp8 models faq:

>Date of introduction:  1978
>Date of withdrawal:    1980 (Displaced by the DECmate)
>Also known as:  DECstation 78 
>
>Technology:  Intersil 6100 microprocessor, packaged in a VT52 case.  The
>	6100 processor was able to run at 4 MHz, but in the VT78, it was
>	only clocked at 2.2 MHz because of the speed of the DRAM used and
>	the deliberate use of graded out chips.
>
>Reason for introduction:  Using TTL MSI and LSI components, DEC could
>	pack their CPU into vacant space in a standard terminal case,
>	allowing PDP-8 systems to compete with personal computers in the
>	small business and office automation market.  This was a natural
>	follow-on to the desk-mounted workstation configurations in which
>	the PDP-8/A was already being sold.
>    ...

The system appears to work (it boots up and runs programs), however, the
ribbon on the DecWriter IV is dried-out.

This system is available to anyone in the S.F. Bay area. The only requirement
is that you make a donation (tax-deductable) of whatever amount you feel
it is worth to: Wat Buddhanusorn, a Thai Buddhist temple in Fremont, CA. This
system was donated to the temple some years ago, but was never really used. They
now use both Macintosh and PCs.

***> I will deliver the system anywhere in or around the S.F. Bay area!

If you are interested, contact me at: jatwood@netcom.com, or FAX me
at: 408 985-2006.

 - John Atwood
-- 
****************************************
John Atwood                jatwood@netcom.COM
****************************************


From jones@cs.uiowa.edu Mon Aug  8 15:21:08 EDT 1994
Article: 985 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!news.duke.edu!convex!cs.utexas.edu!howland.reston.ans.net!math.ohio-state.edu!hobbes.physics.uiowa.edu!news.uiowa.edu!news
From: jones@cs.uiowa.edu (Douglas W. Jones)
Newsgroups: alt.sys.pdp8,alt.answers,news.answers
Subject: PDP-8 Summary of Models and Options (posted every other month)
Followup-To: alt.sys.pdp8
Date: Tue, 8 Aug 94 08:08:08 GMT
Organization: Computer Science, University of Iowa, Iowa City, Iowa, USA
Lines: 1317
Approved: news-answers-request@MIT.Edu
Distribution: world
Expires: 8 Oct 1994 08:08:08 GMT
Message-ID: <325b0v$2ke@nexus.uiowa.edu>
NNTP-Posting-Host: herky.cs.uiowa.edu
Summary: Descriptions of all models of the DEC PDP-8 computer.
	Those posting to alt.sys.pdp8 should read this.
Keywords: FAQ DEC PDP 8
Xref: bigblue.oit.unc.edu alt.sys.pdp8:985 alt.answers:3805 news.answers:25312

Archive-name: dec-faq/pdp8-models
Last-modified: Aug 5, 1994

Frequently Asked Questions about DEC PDP-8 models and options.

	By Douglas Jones, jones@cs.uiowa.edu
	(with help from many folks)

Sites known to carry FTPable copies of this file:

	ftp://rtfm.mit.edu/pub/usenet/alt.sys.pdp8
        ftp://ftp.uu.net/usenet/news.answers/dec-faq
	ftp://src.doc.ic.ac.uk:/pub/usenet/news.answers/alt.sys.pdp8
	ftp://sunsite.unc.edu/pub/academic/computer-science/history/pdp-8/docs

Automatic translations of this document to HTML format (as used by World Wide
Web) are available from:

        http://www.cis.ohio-state.edu/hypertext/faq/usenet/dec-faq/top.html

This posting conforms to RFC1153 USENET digest format (with exceptions due
to the fact that it is not really a digest).

The purpose of this document is to supplement the material in the primary
"Frequently Asked Questions about the PDP-8" file with more detailed
information about the hardware and options of the different models of the
PDP-8 sold by DEC.

Although this document is something of a history of the DEC PDP-8 family,
the primary purpose of this document is as a guide and general outline to
the PDP-8 models and options likely to be encountered by those involved
in collecting and restoring such systems.

Contents:

	What is a PDP-5?
	What is a PDP-8?
	What is a LINC-8?
	What is a PDP-8/S?
	What is a PDP-8/I?
	What is a PDP-8/L?
	What is a PDP-12?
	What is a PDP-8/E?
	What is a PDP-8/F?
	What is a PDP-8/M?
	What is a PDP-8/A?
	What is a VT78?
	What is a DECmate I?
	What is a DECmate II?
	What is a DECmate III?
	What is a DECmate III+?

----------------------------------------------------------------------

Subject: What is a PDP-5?

Date of introduction:  Aug 11, 1963, unveiled at WESCON.
Date of withdrawal:    early 1967.
Total production run:  116.
Price: $27,000

Technology:  The PDP-5 was built with DEC System Modules, the original
	line of transistorized logic modules sold by DEC.  The supply
	voltages were +10 and -15 volts, with logic levels of -3 (logic 1)
	and 0 (logic 0).  Logic was packaged on boards that were about
	4.75 inches high with each card mounted in a metal frame with a
	22 pin edge connector.

	Input output devices were connected to the daisy-chained I/O bus
	using military-style armored cables and connectors.  Use of
	toggle switches (as opposed to slide switches) on the front
	panel was another vestige of military-style design.

Reason for introduction:  This machine was inspired by the success of
	the CDC-160, Seymour Cray's 12 bit minicomputer, and by the
	success of the LINC, a machine that was built by DEC customers
	out of System modules.  These demonstrated that there was a
	market for a small inexpensive computer, and from the start,
	DEC's advertisements were aimed at this market.  "Now you can
	own the PDP-5 computer for what a core memory alone used to
	cost: $27,000", ran one 1964 ad.

Reason for withdrawal:  The PDP-8 outperformed the PDP-5, and did so for
	a lower price.

Compatability:  The core of the PDP-8 instruction set is present, but
	memory location zero is the program counter, and interrupts are
	handled differently.  The Group 1 OPR rotate instructions cannot
	be combined with IAC or CMA; this limits the ability of the
	PDP-5 to support code from later models.

The machine does not support 3 cycle data-break (DMA transfers using
	memory to hold buffer address and word-count information), so
	many later PDP-8 peripherals can not be used on the PDP-5.  In
	addition, DMA transfers are not allowed outside the program's
	current 4K data field, severely limiting software compatability
	on systems with over 4K of memory where either interrupts or
	software initiated changes to the data field during a transfer
	would cause chaos.

Standard configuration:  CPU with 1K or 4K of memory (2K and 3K versions
	were not available).

Peripherals:
	An extended arithmetic element (EAE) was available; this was an
	I/O device, using IOT instructions to evoke EAE operations.  As
	a result, it was not compatable with the later PDP-8 EAEs.  In
	addition, machines with the EAE option had a different front
	panel from those without.

	The type 552 DECtape control and type 555 dual DECtape transports
	were originally developed for the PDP-5 and contemporaneous DEC
	systems such as the PDP-6.

	After the PDP-8 was introduced, DEC offered a bus converter that
	allowed the PDP-5 to support standard PDP-8 negibus ueripherals,
	so long as they avoided using 3-cycle data break transfers.  The
	standard 804 PDP-8 expander box was frequently sold as an
	upgrade to PDP-5 systems.

Survival:  Do any PDP-5 systems survive?

------------------------------

Subject: What is a PDP-8?

Date of introduction:  1965 (Unveiled March 22, in New York).
Date of withdrawal:    1968.
Total production run:  1450.
Also known as:
	Classic PDP-8 (to point out lack of a model suffix)
	Straight-8 (Again, points out the lack of a model suffix)
	PCP-88, an OEM label, used by Foxboro Corporation.
Price: $18500

Technology:  Mostly standard DEC R-series logic modules; these were
	originally discrete component transistor logic, but around the
	time the PDP-8 was introduced, DEC introduced the Flip Chip, a
	hybrid diode/resistor "integrated circuit" on a ceramic substrate.
	These could directly replace some of the discrete components on
	some logic modules, and DEC soon began to refer to all R-series
	modules as flip-chip modules; they even advertised the PDP-8 as
	an integrated circuit computer.  A typical flip-chip module, the
	R111, had three 2-input nand gates and cost $14, with no price
	change from 1965 to 1970.  Some special dual height R-series
	modules were designed specifically for the PDP-8.

	S and B-series logic modules were also used; these are similar
	to their R-series cousins, but with different speed/fanout
	tradeoffs in their design.  Some logic modules have trimmers
	that must be tuned to the context, making replacement of such
	modules more complex than simply swapping boards.

	As with the system modules used in the PDP-5, the supply
	voltages were +10 and -15 volts and the logic levels were -3
	(logic 1) and 0 (logic 0).  Logic was packaged on boards that
	were 2.5 inches wide by 5 inches long.  The card edge connector
	had 18 contacts on 1/8 inch centers.  Some double height cards
	were used; these had two card edge connectors and were 5 1/8
	inches high.  Machine wrapped wire-wrap technology was used on
	the backplane using 24-gauge wire.

	The "negibus" or negative logic I/O bus used -3 and 0 volt logic
	levels in 92 ohm coaxial cable, with 9 coaxial cables bundled
	per connector card and 6 bundles making up the basic bus.  5
	(later 4) more bundles were required to support data-break (DMA)
	transfers.  The total bus length was limited to 50 feet, and bus
	termination was generally kluged in with 100 ohm resistors
	clipped or wrapped into the backplane, although a bus terminator
	card was sometimes used.  Some time after the first year of
	production, flat ribbon cable made of multiple coaxial cables
	was used, and later still, shielded flat stripline cable was used
	(but this cut the allowed bus length by a factor of two).

	Core memory was used, originally made by FERROXCUBE, with a 1.5
	microsecond cycle time, giving the machine an add time of 3
	microseconds.  4K of core occupied an aluminum box 6 inches on a
	side and needed numerous auxiliary flip-chips and for support,
	as well as an array of boards from the core vendor.  It is worth
	noting that the PDP-8 was about as fast as was practical with the
	logic technology used; only by using tricks like memory
	interleaving or pipelining could the machine have been made much
	faster.

Reason for introduction:  This machine was inspired by the success of
	the PDP-5 and by the realization that, with their new Flip-Chip
	technology, DEC could make a table-top computer that could be
	powered by a single standard wall outlet; of course, adding any
	peripherals quickly increased the power requirement!

Reason for withdrawal:  The PDP-8/I was less expensive, and after
	initial production difficulties, it equalled the performance of
	the PDP-8.

Compatability:  This machine defines the core of the PDP-8 instruction
	set, but with restrictions that were lifted on later machines.
	The Group 1 OPR instruction IAC cannot be combined with any of
	the rotate instructions.  If RAR and RAL or RTR and RTL are
	combined, the results are unpredictable (simultaneous set and
	reset of bits of AC results in metastable behavior).  The IOT 0
	instruction was used for the internal type 189 ADC, and not for
	the later CAF (clear all flags) instruction.  As a result, if
	the ADC option was not present, IOT 6004 (or microcoded
	variants) would hang the machine.

	The SWP instruction (exchange AC and MQ) never works, even if
	the extended arithmetic element is present.  This works on later
	models when the EAE is present, although it was only documented
	with the introduction of the PDP-8/E.  Finally, the EAE lacks
	the SCL (shift count load) instruction that is present on later
	models.

	On machines with 8K or more, an attempt to change the data field
	to a non-existant field caused a bizarre double-indirect and
	skip instruction execution that must be accounted for in memory
	diagnostics.

Standard configuration:  The PDP-8 was sold as a CPU with 4K of memory,
	a 110 baud current loop teletype interface and an ASR 33 Teletype.
	In addition, the standard in-cabinet logic includes support for
	the full negibus interface, including data-break (DMA) transfers.

	Both a rack-mount model with rosewood trim and an elegant
	plexiglass enclosed table-top configuration were standard.  Under
	the skin, the basic machine occupies a volume 33 inches high by
	19 inches wide by 22 inches deep.  The two halves of the backplane
	are mounted vertically, like the covers of a book, with the
	spine in back and circuit modules inserted from the two sides.
	Sliding the CPU out of the relay rack or removing the plexiglass
	covers allows the backplane to swung open to access the wires-wrap.

Expandability:  In-cabinet options include the type 182 extended
	arithmetic element (EAE), the type 183 memory extension control
	subsystem, and the type 189 low performance analog to digital
	converter (ADC).  Prewired backplane slots were reserved for
	all of these.

	Expansion beyond 4K of memory requires rack space for the
	rack-mounted type 184 memory module; each such module adds one
	4K field of memory, up to a maximum of 32K.  The rack-mount CPU
	occupied a large part of one rack, allowing room for a single
	type 184 memory expansion module below the CPU; generally, a
	second rack was needed for added peripherals or memory.

	At the end of the production run, some PDP-8 systems were sold
	with PDP-8/I memory, allowing room for an additional 4K without
	need for an expansion chassis.  These nonstandard machines were
	very difficult to maintain!

Peripherals:  At the time of introduction, the following negibus
	peripherals were offered.

	-- Type 750C high speed paper tape reader and control.
	-- Type 75E high speed paper tape punch and control.
	-- Type 138E analog to digital converter.
	-- Type 139E analog multiplexor.
	-- Type 34D oscilloscope display control (dual digital to analog).
	-- Type 350B incremental (CalComp) plotter control.
	-- Type 451 card reader and control.
	-- Type 450 card punch control for IBM Type 523 punch.
	-- Type 64 (later 645) Mohawk line printer and control.
	-- Type RM08 serial magnetic drum system (up to 256K words).
	-- Type 552 DECtape control (for type 555 DECtape drives).
	-- Type 57A magnetic tape control (IBM type 729 drive).
	-- Type 580 magnetic tape system.

	By 1966, the following peripherals had been added to the line:

	-- Type AA01A three-channel digital to analog converter.
	-- Type CR01C card reader control.
	-- Type TC01 DECtape control for up to 8 TU55 transports.
	-- Type 251 drum (8-256 tracks, 8 sectors/track, 128 words/sector).
	-- Type 645 line printer control.
	-- Type 680 data communications system (allows 64 teletypes).

	By 1967, the following peripherals had been added to the line:

	-- Type AF01 analog to digital converter and multiplexor.
	-- Type AX08 parallel digital input port.
	-- Type 338 Programmed Buffered Display (vector graphics).

	By 1968, the following new peripheral had been added:

	-- Type DF32 fixed head disk system (32K to 256K words).
	-- Type BE01 OEM version of the TC01 (no blinking lights).
	-- Type BE03 dual TU55 drive for the TC01 or BE01.

	Finally, as DEC abandoned the negibus, they introduced the
	DW08B negibus to posibus converter so newer posibus
	peripherals could be used on older negibus machines, and the
	DW08A posibus to negibus converter to allow use of old
	peripherals on new machines.

Survival:  Many classic PDP-8 systems survive to this day

------------------------------

Subject: What is a LINC-8?

Date of introduction:  1966 (during or before March).
Date of withdrawal:    1969
Total production run:  142.
Price: $38,500

Technology:  DEC Flip Chip modules, as in the PDP-8, with a LINC CPU
	partially reimplemented in Flip Chips and partially emulated
	with PDP-8 instructions.  (The original LINC was built from
	the same System Modules used in the PDP-5.)

Compatability:  The PDP-8 part of the machine was identical to the PDP-8.

Reason for withdrawal:  The PDP-12 accomplished the same goals at a lower
	cost.

Standard configuration:  The combined PDP-8/LINC CPU, plus 4K of memory
	was central to the system.  The set of peripherals bundled with
	the machine was impressive:

	-- An ASR 33 Teletype modified for the LINC character set.
	-- Two LINCtape drives.
	-- 8 analog to digital converter channels with knob inputs.
	-- Another 8 ADC channels with jack inputs.
	-- 6 programmable relay outputs, good up to 60 Hz.
	-- 1 Tektronix 560 oscilliscope, somewhat modified.

	The X and Y axis control for the scope came from DACs attached
	to the LINC's AC and MB registers, respectively.

Expandability:

	In addition to standard PDP-8 peripherals, up to 3 additional
	pairs of LINCtape drives could be added, for a total of 8 drives.
	The design of the type 555 dual DECtape transport was based on
	that of the LINCtape drive.

	Up to 2 additional ranks of 8 ADC channels could be added.

	Remote oscilliscope could be added.

Survival:  One LINC-8 is known to be in operable condition today.

------------------------------

Subject: What is a PDP-8/S?

Date of introduction:  1966 (Unveiled, Aug 23, WESCON, Los Angeles).
Date of withdrawal:    1970.
Total production run:  1024.
Price: $10,000

Technology:  DEC Flip Chip modules and core memory, as in the PDP-8.
	Unlike the PDP-8, the PDP-8/S memory module was mounted between
	a pair of quad-height single-width boards that plugged into the
	standard flip-chip sockets (this was sold separately as the H201
	core memory unit, at $2000 for 4K by 13 bits).

Reason for introduction:  This machine was developed as a successful
	exercise in minimizing the cost of the machine.  It was the
	least expensive general purpose computer made with second
	generation (discrete transistor) technology, and it was one of
	the smallest such machines to be mass produced (a number of
	smaller machines were made for aerospace applications).  It was
	also incredibly slow, with a 36 microsecond add time, and some
	instructions taking as much as 78 microseconds.  By 1967, DEC
	took the then unusual step of offering this machine for off the
	shelf delivery, with one machine stocked in each field office
	available for retail sale.

Reason for withdrawal:  The PDP-8/L vastly outperformed the PDP-8/S, and
	and it did so at a lower price.

Compatability:  The core of the PDP-8 instruction set is present, but
	there are a sufficient number of incompatabilities that, as with
	the PDP-5, many otherwise portable "family of 8" programs will
	not run on the PDP-8/S.  Perhaps the worst incompatability is
	that the Group 1 OPR instruction CMA cannot be combined with any
	of the rotate instructions; as with the PDP-8, IAC also cannot
	be combined with rotate.

Standard configuration:  CPU with 4K of memory, plus PT08 110 baud current
	loop teletype interface and teletype.  Both a rack-mount and
	table-top versions were sold (both 9" high by 19" wide by 20"?
	deep).  The rack mount version included slides so it could be
	pulled out for maintenance.

Expandability:  The CPU supported the standard PDP-8 negibus, but I/O
	bandwidth was 1/5 that of the PDP-8.  Thus, most, but not all
	PDP-8 peripherals could be used.  A few DEC peripherals such as
	the DF32 came with special options such as interleaving to slow
	them down for compatability with the PDP-8/S.  The speed problems
	were such that there was never any way to attach DECtape to this
	machine.

Survival:  Because they were so slow, PDP-8/S systems were quickly
	discarded as newer machines became available for comparable prices;
	thus, they are less common today than the Classic PDP-8, even
	though comparable numbers were made.  A few survive in working
	condition.

------------------------------

Subject: What is a PDP-8/I?

Date of introduction:  1968 (announced before December '67)
Date of withdrawal:    1971.
Total production run:  3698.

Technology:  DEC M-series logic modules, called M-series flip-chips
	as the term flip-chip was applied to the module format instead
	of to DEC's hybrid integrated circuits.  M-series modules used
	TTL chips, with a +5 volt supply, packaged on the same board
	format used with the original flip-chips, but with double-sided
	card-edge connectors (36 contacts instead of 18).  Modules were
	limited to typically 4 SSI ICs each.  The M113, a typical
	M-series module, had 10 2-input nand gates and cost $23 in 1967
	(the price fell to $18 in 1970).  Wire-wrapped backplanes used
	30-gauge wire.

	The PDP-8/I, as originally sold, supported the then-standard
	PDP-8 negibus.  4K words of core were packaged in a 1 inch thick
	module made of 5 rigidly connected 5 by 5 inch two-sided printed
	circuit boards.  Connectors and support electronics occupied an
	additional 32 backplane slots.

	Nominally, the core memory (which, curiously, used a negative
	logic interface!) was supposed to run at a 1.5 microsecond cycle
	time, but many early PDP-8/I systems were delivered running at a
	slower rate because of memory quality problems.  DEC went through
	many vendors in the search for good memory!  The memory interface
	was asynchronous, allowing the CPU to delay for slow memory.  DEC
	continued to make the classic PDP-8 until the problems with
	memory speed were solved.

Reason for introduction:  This machine was developed in response to the
	introduction of DIP component packaging of TTL integrated
	circuits.  This allowed a machine of about the same performance
	as the original PDP-8 to fit in about half the volume and sell
	for a lower price.

Reason for withdrawal:  The PDP-8/E made slight performance improvements
	while undercutting the price of the PDP-8/I.

Compatability:  The core of the PDP-8 instruction set is present, and
	unlike the original PDP-8, IAC can be combined with rotate in a
	single microcoded Group 1 OPR instruction.  Combined RAR and RAL
	or RTR and RTL produce the logical and of the expected results
	from each of the combined shifts.

	If the extended arithmetic element is present, the SWP (exchange
	AC and MQ) instruction works, but this was not documented.

	On large memory configurations, memory fetches from a nonexistant
	memory field take about 30 microseconds (waiting for a bus
	timeout) and then they return either 0000 or 7777 depending on
	the memory configuration and the field that was addressed.

	A front panel bug prevented continue after load-address without
	first clearing the machine.

Standard configuration:  CPU with 4K of memory, plus 110 baud current
	loop teletype interface.  Pedestal, table-top and rack-mount
	versions were made.  The pedestal mounted version was futuristic
	looking; the table-top version split the pedistal, with the CPU
        on the table and the power supply (the base of the pedistal) on
	the floor beside the table.  The standard rack-mounted version
	had the power supply bolted to the right side of the rack while
	the CPU, mounted on slides, slid out of the left side of the rack.

Expandability: 4K of memory could be added internally, and additional
	memory could be added externally using a rack-mounted MM8I memory
	expansion module for each 4K or 8K addition over 8K.

	The backplane of the PDP-8/I was prewired to hold a Calcomp
	plotter interface, with the adjacent backplane slot reserved
	for the cable connection to the plotter.  There may be other
	built-in options.

	Initially, the CPU was sold with bus drivers for the PDP-8
	negibus, allowing this machine to support all older DEC
	peripherals, but later machines were sold with posibus interfaces,
	and many older machines were converted in the field.

	A posibus to negibus converter, the DW08A, allowed use of all
	older PDP-8 peripherals, with small modifications.  The change
	from negibus to posibus during the period of PDP-8/I production
	leads to confusion because surviving CPUs and peripherals may
	have any of three I/O bus configurations: Negibus, early posibus,
	or final posibus.  The early posibus used the same connectors
	and cables as the negibus, with only 9 conductors per connector,
	while the final posibus used both sides of the connector paddles
	for 18 bus lines per connector.  Y-shaped cables for converting
	from one physical bus layout to the other were available.  To
	add to this confusion, some negibus PDP-8/I systems were rewired
	to use 18 conductor posibus cables with negative logic!

	Eventually, an add-on box was sold that allowed PDP-8/E (OMNIBUS)
	memory to be added to a PDP-8/I.  Additionally, Fabritek sold a
	24K memory box for the 8/I and PDP-12.

Survival:  Many PDP-8/I systems are in operating condition.

------------------------------

Subject: What is a PDP-8/L?

Date of introduction:  1968 (announced before August '68)
Date of withdrawal:    1971.
Total production run:  3902.
Price: $8,500

Technology:  DEC M-series flip Chip modules, as in the PDP-8/I, with the
	same core memory as the 8/I, but with a memory cycle cycle of 1.6
	microseconds to avoid the speed problems that plagued early -8/I
	systems.

	The positive I/O bus, or posibus, was a 100 ohm bus clamped
	between 0 and 3 volts with TTL drivers and receivers.  This was
	packaged with 18 signal lines per 2-sided interconnect cable,
	using double-sided shielded mylar ribbon cable in most cases.
	Electrically, coaxial cable could be used, but the slots in the
	CPU box were too small for this.

Reason for introduction:  This machine was developed as a moderately
	successful exercise using M-series logic to produce a lower cost
	but moderately fast machine.  The idea was to cut costs by
	limiting provisions for expansion.

Reason for withdrawal:  The PDP-8/E made performance improvements while
	slightly undercutting the price of the PDP-8/L.

Compatability:  The core of the PDP-8 instruction set is present, but
	all Group 3 OPR instructions are no-ops, even the Group 3 version
	of the CLA instruction.  This is because there was no provision
	made for adding an EAE to this machine.  Microcoding RAR and RAL
	together works as in the PDP-8/I.  Finally, a new front panel
	feature was added, the protect switch.  When thrown, this makes
	the last page of the last field of memory read-only (to protect
	your bootstrap code).

	The instruction to change the data field on an 8/L becomes a
	no-op when the destination data field is non-existant; on all
	other machines, attempts to address non-existant fields are
	possible.  One option for expanding the 8/L was to add a box that
	allowed 8/E memory modules to be added to the 8/L; when this
	was done, access to nonexistant data fields becomes possible and
	always returns 0000 on read.

Standard configuration:  A CPU with 4K of memory, plus 110 baud current
	loop teletype interface was standard.  Both rack-mount and
	table-top versions were sold (both 9" high by 19" wide by 21"
	deep).  The backplane was on top, with modules plugged in from
	the bottom.  The rack-mount version could be slid out for
	maintenance.

Expandability:  The CPU supported a new bus standard, the PDP-8 posibus.
	There is little space for in-box peripherals, but an expander
	box with the same volume as the CPU was available, the BA08A;
	this was prewired to hold an additional 4K of memory and to
	support in-box peripheral interfaces for such devices as a
	Calcomp plotter interface, a card-reader interface, a 4 line
	asynch terminal interface, a real-time clock, and more.

	DEC eventually offered the BM12L, an 8K expansion box that is
	essentially the same as the MM8I, but using positive logic and
	thus incompatable with the -8/I and -12.  This allowed a total
	memory of 12K on a PDP-8/L.  This contains precisely the modules
	needed to upgrade a 4K PDP-8/I or PDP-12 to an 8K machine, or to
	populate an MM8I box to add 8K of additional memory to an 8/I or
	PDP-12.

	Finally, DEC eventually offered a box allowing PDP-8/E (OMNIBUS)
	memory to be used with the PDP-8/L.  PDP-8/L configurations with
	over 8K of memory were awkward because the front panel only
	showed one bit of the extended memory address.  As a result,
	extra lights and switches for the additional bits of the memory
	address were mounted on the front of the memory expander boxes
	for the large configurations.

	A variety of posibus peripherals were introduced, most of which
	were built with the option of negibus interface logic (the -P
	and -N suffixes on these new peripherals indicated which was
	which).  Many early PDP-8/L systems were sold with DW08A bus
	level converters to run old negibus peripherals.

	Posibus peripherals introduced after the PDP-8/L (and also used
	with posibus versions of the PDP-8/I) included:

	-- The TC08 DECtape controller (for 8 TU55 or 4 TU56).
	-- The DF32D fixed head disk controller (a posibus DF32).
	-- The FPP-12 floating point processor.
	-- The TR02 simple magnetic tape control.
	-- The RK08 disk subsystem, 4 disk packs, 831,488 words each.

Survival:  Many PDP-8/L systems are in operating condition.

------------------------------

Subject: What is a PDP-12?

Date of introduction:  1969 (February or earlier).
Date of withdrawal:    1973.
Total production run:  3500?
Price: $27,900

Technology:  DEC M-series flip Chip modules, as in the PDP-8/I.

Reason for introduction:  This machine was developed as a follow-up to
	the LINC-8.  Originally it was to be called the LINC-8/I, but
	somehow it got its own number.  In effect, it was a PDP-8/I with
	added logic to allow it to execute the LINC instruction set.

Reason for withdrawal:  The LAB-8/E and the LAB-11 (a PDP-8/E and a
	PDP-11/20 with lab peripherals) eventually proved the equal of
	the PDP-12 in practice, and LINC compatability eventually proved
	to be of insufficient value to keep the machine alive in the
	marketplace.
		
Compatability:  This machine is fully compatable with the PDP-8/I, with
	additional instructions to flip from PDP-8 mode to LINC mode and
	back.  IOT 0 could enable the API, causing trouble with later
	PDP-8 code that assumes IOT 0 is "Clear all flags".  Also, the
	DECtape instruction DTLA (6766) becomes part of a stack-oriented
	extension to the instruction set, PUSHJ, on late model (or field
	updated) machines with the KF12-B backplane.

	The PDP-12 supported trapping of those LINC functions that were
	emulated by software on the LINC-8.  This allowed it to run many
	LINC-8 bootable systems (but not all, due mostly incompatabilities
	in LINKtape support), and it allowed such things as emulation of
	LINKtape instructions for reading and writing disk.

	The TC12F Linktape controller could, with appropriate software,
	read or write DECtape.  This support is unreliable, and is not
	software compatable with the TC01 or TC08 DECtape controller.

Standard configuration:  PDP-8/LINC CPU with 4K of memory, plus 110 baud
	current loop interface, plus output relay registers.  In
	addition, the standard configuration included either two TU55 or
	one TU56 drive, with a PDP-12 only controller allowing it to
	handle LINCtape.  In addition, a 12" scope was always included,
	with a connector that can connect to a second scope.

Expandability:  An analog to digital converter and multiplexor was needed
	to fully support knob-oriented LINC software.

	Other options included:

	-- the KW12 programmable lab clock.
	-- additional TU55 or TU56 drives (up to 8 transports).
	-- the BA12 expander box
	-- the PC05 paper tape reader punch (needs the BA12).

	Fabritek made a 24K memory box that could be added to a PDP-8/I or
	PDP-12.

Survival:  A few PDP-12 systems are in operating condition.

------------------------------

Subject: What is a PDP-8/E?

Date of introduction:  1970 (during or before August).
Date of withdrawal:    1978.
Also known as:
	Industrial-8 (with a red color scheme)
	LAB-8/E (with a green color scheme)
Price: $7,390

Technology: SSI and MSI TTL logic were used on these boards, and the
	entire CPU fit on 3 boards.  Nominally, these were DEC M-series
	flip Chip modules, but in a new large format, quad-high (10.5
	inch), extended-length (9 inch, including card-edge connector,
	excluding handles).  The terms used for board height and length
	are based on the original working assumption that all flip-chips
	were plugged horizontally into a vertially mounted card-edge
	connector.  On the PDP-8/E, the cards were plugged vertically
	down into a horizontally mounted connector, so many users
	incorrectly refer to these boards as quad-wide double-high.

	Interconnection between boards was through a new bus, the OMNIBUS.
	This eliminated the need for a wire-wrapped backplane, since all
	slots in the bus were wired identically.  A new line of peripheral
	interfaces was produced, most being single cards that could be
	plugged directly into the inside the main enclosure.  These
	included a set of posibus adapters allowing use of older
	peripherals on the new machine.

	Interboard connectors were needed for some multiboard options,
	including the CPU and memory subsystems.  These used standard
	36-pin backplane connectors on the opposite side of the board
	from the backplane.  Some boards, notably memory boards, had a
	total of 8 connector fingers, 4 for the omnibus and 4 for
	interboard connectors.

	The core memory cycle time was 1.2 or 1.4 microseconds, depending
	on whether a read-modify-write cycle was involved (a jumper would
	slow all cycles to 1.4 microseconds).  A 4K core plane was
	packaged on a single quad-wide double-high board, with most of
	the drive electronics packed onto two adjacent boards.  Soon after
	the machine was introduced, an 8K core plane was released in the
	same format.

Reason for introduction:  The cost of the PDP-8/I and PDP-8/L was
	dominated by the cost of the interconnect wiring, and this cost
	was high as a result of the use of small circuit boards.  By
	packing a larger number of chips per board, similar function
	could be attained in a smaller volume because less interboard
	communication was required.  The PDP-8/E exploited this to achieve
	a new low in cost while attaining a new high in performance.

Reason for withdrawal:  This machine was slowly displaced by the PDP-8/A
	as the market for large PDP-8 configurations declined in the face
	of pressure from 16 bit mini and microcomputers.

Compatability:  As with the PDP-8/I and PDP-8/L, there are no limits on
	the combination of IAC and rotate instructions.  Unlike the early
	machines, basic Group 3 OPR operations for loading and storing
	the MQ register work even if there is no extended arithmetic
	element.  Finally, a new instruction was added, BSW; this swaps
	the left and right bytes in AC, and is encoded as a Group 1 OPR
	instruction using the "double the shift count bit".

	An odd quirk of this machine is that the RAL RAR combination ands
	the AC with the op-code, and the RTR RTL combination does an
	effective address computation loading the high 5 bits of AC with
	the current page and the lower bits of AC with the address field
	of the instruction itself!

	The EAE has a new mode, mode B.  Previous EAE designs were
	single-mode.  Mode B supports a large set of 24 bit operations
	and a somewhat more rational set of shift operations than the
	standard EAE.  All prior EAE designs would hang on the microcoded
	CLA NMI (clear/normalize) instruction applied to a nonzero AC.
	This instruction is redefined to be a mode changing instruction
	on the 8/E.

Standard configuration:  A CPU with 4K of memory, plus 110 baud current
	loop teletype interface.  Both a rack-mount table-top versions
	were sold (both 9" high by 19" wide by 21" deep).  The rack mount
	version was mounted on slides for easy maintenance.  The OMNIBUS
	backplane was on the bottom, with boards inserted from the top.

	The standard OMNIBUS backplane had 20 slots, with no fixed
	assignments, but the following conventional uses:

	-- KC8E programmer's console (lights and switches)
	-- M8300 \_ KK8E CPU registers
	-- M8310 /  KK8E CPU control
	--
	--
	-- M833  - Timing board (system clock)
	-- M865  - KL8E console terminal interface.
	--
	--
	--   -- space for more peripherals
	--
	--
	-- M849  - shield to isolate memory from CPU
	-- G104  \
	-- H220   > MM8E 4K memory
	-- G227  /
	--
	--   -- space for more memory
	--
	-- M8320 - KK8E Bus terminator

	Most of the early boards with 3 digit numbers were defective
	in one way or another, and the corrected boards added a trailing
	zero.  Thus, the M833 was generally replaced with an M8330, and
	the M865 was replaced with the M8650.

Expandability:  The following are among the OMNIBUS boards that could be
	added internally:

	-- M8650 - KL8E RS232 or current loop serial interface.
	-- M8340 \_ Extended arithmetic element.
	-- M8341 /  (must be attached in two slots adjacent to CPU.
	-- M8350 - KA8E posibus interface (excluding DMA transfers).
	-- M8360 - KD8E data break interface (one per DMA device).
	-- M837  - KM8E memory extension control (needed for over 4K).
	-- M840  - PC8E high speed paper tape reader-punch interface.
	-- M842  - XY8E X/Y plotter control.
	-- M843  - CR8E card reader interface.

	There were many other internal options.  There was room in the
	basic box for another 20 slot backplane; taking into account the
	2 slots occupied by the M935 bridge between the two backplanes,
	this allowed 38 slots, and a second box could be added to
	accomodate another 38 slot backplane, bridged to the first box by
	a pair of BC08H OMNIBUS extension cables.

	Given a M837 memory extension control, additional memory could be
	added in increments of 4K by adding G104, H220, G227 triplets.
	The suggested arrangement of boards on the OMNIBUS always
	maintained the M849 shield between memory other options.  The
	one exception was that the M8350 KA8E and M8360 KD8E external
	posibus interfaces were typically placed at the end of the
	OMNIBUS right before the terminator.

	The following options were introduced later, and there were many
	options offered by third party suppliers.

	-- G111  \
	-- H212   > MM8EJ 8K memory
	-- G233  /
	-- M8357 -- RX8E interface to RX01/02 8" diskette drives.
	-- M7104 \
	-- M7105  > RK8E RK05 Disk Interface
	-- M7106 /
	-- M8321 \
	-- M8322  \ TM8E Magtape control for 9 track tape.
	-- M8323  /
	-- M8327 /

	At one point, DEC packaged a PDP-8/E in a desk with no front panel
	controls other than power and bootstrap switch, along with an RX01
	accessable from the front and a VT50 on top.  This was sold as
	the Class-ic system, with an intended market in the classroom
	(hence the name); it was the forerunner, in terms of packaging,
	of many later DEC office products.

Survival:  It is still fairly common to find PDP-8/E systems on the
	surplus market, recently removed from service and in working
	condition or very close to it.  A modest number are no-doubt
	still in service, and there is still a limited amount of
	commercial support from both DEC and third-party vendors.

------------------------------

Subject: What is a PDP-8/F?

Date of introduction:  1972.
Date of withdrawal:    1978.

Technology:  an OMNIBUS machine, as with the PDP-8/E.  First use
	of a switching power supply in the PDP-8 family.

Reason for introduction:  The PDP-8/E had a large enough box and a large
	enough power supply to accomodate a large configuration.  By
	shortening the box and putting in a small switching power supply,
	a lower cost OMNIBUS machine was possible.

Reason for withdrawal:  The PDP-8/A 800 displaced this machine, providing
	similar expansion capability at a lower cost.

Compatability:  The PDP-8/F used the PDP-8/E CPU and peripherals.

Standard configuration:  Identical to the PDP-8/E, except that the KC8E
	front panel was replaced with a KC8M front panel that had LEDs
	instead of incandescent lights; this front panel could also be
	installed on PDP-8/E systems, but the PDP-8/E front panel could
	not be used on a PDP-8/F because of the lack of a +8 supply for
	the lights.  The original PDP-8/F box had a defective power
	supply, but a revised (slightly larger) box corrected this
	problem.

Expandability:  This machine could be expanded using all PDP-8/E OMNIBUS
	peripherals, including the external expansion chassis.  The
	relatively small internal power supply and the lack of room for
	a 20 slot bus expander inside the first box were the only
	limitations.  There were minor compatability problems with some
	options, for example, the power-fail auto-restart card, as
	originally sold, was incompatable with the PDP-8/F power supply.

Survival:  As with the PDP-8/E, these machines are moderately common on
	the surplus market, and frequently in working condition.

------------------------------

Subject: What is a PDP-8/M?

Date of introduction:  1972.
Date of withdrawal:    1978.

Technology:  This machine was a PDP-8/F (with a PDP-8/E CPU)

Reason for introduction:  DEC knew that OEM customers were an important
	market, so they packaged the PDP-8/F for this market, with no
	hardware changes behind the front panel.

Reason for withdrawal:  Same as the PDP-8/F

Compatability:  The PDP-8/M used the PDP-8/E CPU and peripherals.

Standard configuration:  Identical to the PDP-8/F, except that the KC8M
	front panel was replaced with a minimal function panel and the
	color scheme was different.  Because of this, one of the following
	options were required:

	-- M848  -- KP8E Power fail and auto-restart.
	-- M847  -- MI8E Hardware Bootstrap Loader.

	Expandability:  All options applying to the PDP-8/F applied.  In
	addition, the KC8M front panel (standard with the PDP-8/F) was
	available as an option.

Survival:  As with the PDP-8/F.

------------------------------

Subject: What is a PDP-8/A?

Date of introduction:  1975
Date of withdrawal:    1984
Also known as:
	DECdatasystem 310 (an 8/A 500 sold as a word-processor)

Technology:  This machine used the OMNIBUS with a new single-board CPU.
	The backplane was reoriented so that boards plugged into it from
	the front, with the board held horizontally.

Reason for introduction:  Using TTL MSI and LSI components, DEC was able
	to reduce the PDP-8 CPU to a single oversize board (formally, hex
	height, double width).  Similarly, they were able to make an 4K
	core memory board, and later, an 8K board in this format, and they
	were able to introduce a static RAM card using semiconductor
	memory.  The minimum system was reduced to 3 boards.

	The market for the PDP-8 was dominated by small systems, with
	fewer and fewer customers needing large-scale expandability.
	Thus, the 20 slot backplane of the early Omnibus machines was too
	big; with the new single board CPU and memory, a 12 slot backplane
	was enough, allowing further cost reductions.

Reason for withdrawal:  The market for the PDP-8 family was shrinking in
	the face of pressure from larger minicomputers and the new
	monolithic microcomputers.  After 1975, many PDP-8 sales were to
	captive customers who had sufficient software investments that
	they could not afford to move.  Only the word-processing and
	small business markets remained strong for first-time PDP-8
	sales, and in these, the specialized DEC VT-78 and DECmate
	machines were more cost effective than the open architecture
	OMNIBUS machines.
		
Compatability:  The new PDP-8/A CPU was largely compatable with the
	PDP-8/E CPU, except that the combination of RTR and RTL (Group 1
	OPR instructions) loaded the next address.  The power-fail
	auto-restart option included the standard skip on power low
	instruction, but also a new skip on battery empty instruction to
	test the battery used for back-up power on the new solid state
	memory.

	The standard parallel port on the M8316 port was not software
	compatable with the earlier line-printer interfaces used with
	device code 66.

Standard configuration:  The PDP-8/A was sold with a new short OMNIBUS
	backplane, mounted on its side above a power supply and a
	battery to back up the solid state memory.  The minimum
	configuration included a limited function control panel and the
	following components on the bus:

	-- M8315 -- KK8A CPU board
	-- M???? -- MS8A 1K to 4K solid state memory.
	-- M???? -- MR8A ROM companion for the MS8A.
	-- M8316 -- DKC8AA serial/parallel interface and clock.

	The M8316 board contained a remarkable but useful hodgepodge of
	commonly used peripherals, including the console terminal
	interface, a parallel port, the power/fail auto-restart logic,
	and a 100 Hz real time clock.

	The original configuration sold had a 10 slot backplane and a
	poor power supply.  The later base model had a 12 slot backplane,
	the 8/A 400.

Expandability:  All PDP-8/E peripherals and options could be used with
	the PDP-8/A.  The KK8A cpu was not as fast as the KK8E used in
	the PDP-8/E, but the KK8E CPU could be substituted for the KK8A
	CPU, and many PDP-8/A systems were sold with this substitution.

	A box with a 20 slot backplane, the 8/A 600, was available for
	large configurations.  A pair of PDP-8/A backplanes could be
	connected using BC08H cables, and there was a special cable,
	the BC80C, for connecting a hex wide 8A backplane to a PDP-8/E,
	-8/F or -8/M backplane.

	By late 1975, the PDP-8/A was being sold in a workstation
	configuration, with the CPU and dual 8" diskette drives in a desk
	with a video terminal (VT52) and letter quality printer on top.
	This followed the pattern set by the Class-ic packaging of the
	PDP-8/E, but it was aimed at the word-processing market.

	The following additional PDP-8/A (hex) boards were offered:

	-- G649  \_ MM8AA 8K Core stack (too slow for 8/E CPU!).
	-- H219A /  MM8AA 8K Core memory control.
	-- G650  \_ MM8AB 16K Core stack (ok for 8/E CPU!).
	-- H219B /  MM8AB 16K Core memory control.
	-- M???? -- MR8F 1K ROM (overlayable with core).
	-- M8317 -- KM8A memory extender (with variations).
	-- M8319 -- KL8A 4 channel RS232 or current loop serial I/O.
	-- M8433 -- RL8A controller for 1 to 4 RL01/RL02 disk drives.
	-- M???? -- FPP8A floating point processor.

	The PDP-8/A model 800 was the same as the model 600, but with the
	FPP8A floating point processor included as part of the package.

	-- M8416 -- KT8AA Memory management unit for up to 128K.
	--       -- KC8AA Programmer's Console (requires M8316)
	-- M8417 -- MSC8DJ 128K DRAM MOS Memory.

	Note that memory extension to 128K was a new PDP-8/A feature that
	was necessarily incompatable with the older PDP-8 memory expansion
	options, although the conventional PDP-8 memory expansion
	instructions still operate correctly on the first 32K.  Access to
	additional fields involved borrowing IOT instructions that were
	previously dedicated to other devices.

	The MM8A options require the use of a box with a -20V power supply.
	Also, the use of the MSC8 DRAM memory cards requires a CPU that
	supports the memory stall signal, early PDP-8/E CPUs did not.

Survival:  As with the PDP-8/E, these machines are moderately common on the
	surplus market and a modest number are still in use.  Because the
	original machines were less expensive than and slower than 8/E,
	they are more likely to be simply discarded instead of sold as
	surplus.

------------------------------

Subject: What is a VT78?

Date of introduction:  1978
Date of withdrawal:    1980 (Displaced by the DECmate)
Also known as:  DECstation 78 

Technology:  Based on the Intersil/Harris 6120 microprocessor, packaged
	in a VT52 case.  The 6120 processor was able to run at 4 MHz, but
	in the VT78, it was only clocked at 2.2 MHz because of the speed
	of the DRAM used and the deliberate use of graded out chips.

Reason for introduction:  Using TTL MSI and LSI components, DEC could
	pack a system into vacant space in a standard terminal case,
	allowing PDP-8 systems to compete with personal computers in the
	small business and office automation market.  This was a natural
	follow-on to the desk-mounted workstation configurations in which
	the PDP-8/A was already being sold.

Compatability:  The Group I OPR combinations RAL RAR and RTL RTR are
	no-ops.  Unlike all earlier PDP-8 models, autoindex locations
	10 to 17 (octal) only work in page zero mode; these operate like
	all other memory locations when addressed in current page mode
	from code running on page zero.  Other than this, it is fully
	PDP-8/E compatable, even at the level of I/O instructions for
	the standard periperals; this was the last PDP-8 to offer this
	level of compatability.

	It was not possible to continue from a halt without restarting
	the machine.  In addition, none of the peripherals available on
	this machine needed DMA (data break) transfers.

Standard configuration:  The VT78 was sold with 16k words of DRAM with
	the keyboard and display of the VT52 terminal.  An RX01 dual 8"
	diskette drive was standard, packaged in the pedestal under the
	terminal.  The console (device 03/04) and the serial ports
	(devices 30/31 and 32/33) are compatible with the M8650 KL8E,
	with the latter extended to allow software controlled baud rate
	selection.  There are two parallel ports; device 66 (compatible
	with the M8365 printer controller) and device 47, compatible with
	the nonstandard port on the M8316 DKC8AA.  There is also a 100Hz
	clock compatible with the clock on the M8316 DKC8AA.

	The standard ROM boots the system from the RX01 after setting the
	baud rates to match that selected by the switches on the bottom
	of the VT52 case.

Expandability:  This was a closed system, with few options.  The base
	configuration was able to support two RX01 drives (later RX02),
	for a total of 4 transports.  Various boot ROM's were available,
	including a paper-tape RIM loader ROM for loading diagnostics
	from tape.  Another ROM boots the system from a PDP-11 server in
	the client/server configuration used by WPS-11.

Survival:  There are probably many VT78 systems still in use.
	

------------------------------

Subject: What is a DECmate I?

Date of introduction:  1980
Date of withdrawal:    1984 (Phased out in favor of the DECmate II)
Also known as:  DECmate (prior to the DECmate II, no suffix was used)
		VT278

Technology:  Based on the Intersil/Harris 6120 microprocessor,
	packaged in a VT-100 box with keyboard and display.

Reason for introduction:  This machine was aimed primarily at the market
	originally opened by the VT78, using the IM6120 as a substitute
	for the older 6100 chip and optimizing for minimum cost and mass
	production efficiency.

Compatability:  A new feature was introduced in the 6120 microprocessor:
	The Group I OPR combination RAL RAR was defined as R3L, or rotate
	accumulator 3 places left, so that byte swap (BSW) is equivalent
	to R3L;R3L.  RTR RTL remained a no-op, as in the 6100.

	Also, the EAE operations not implemented in the basic CPU cause
	the CPU to hang awaiting completion of the operation by a
	coprocessor.  Unfortunately, no EAE coprocessor was ever offered.

	The printer port offered software baud-rate selection compatable
	with the VT78 baud-rate selection scheme.  The dual-port data
	communications option was flexible but completely incompatable
	with all previous PDP-8 serial ports.

	The console and printer ports are not fully compatable with the
	earlier PDP-8 serial ports.  Specifically, on earlier serial
	interfaces, it was possible to test flags without resetting them,
	but on the DECmate machines, testing the keyboard input flag
	always resets the flag as a side effect.  In addition, on the
	console port, every successful test of the flag must be followed
	by reading a character or the flag will never be set again.

	It was not possible to continue from a halt without restarting
	the machine.

	The large amount of device emulation performed by the CPU in
	supporting screen updates severely limits the ability of the
	system to run in real time.

Standard configuration:  The DECmate I was sold with 32k words of memory,
	with a small control memory added to handle control/status,
	console device emulation and boot options.  The console terminal
	keyboard and display functions are largely supported by code
	running in control memory (a less expensive alternative to
	dedicating hardware for this, as was done in the VT78).

	The DECmate I came with an integral printer port, compatable with
	the VT78 (device 32/33), and it had an RX02 dual 8 inch diskette
	drive, mounted in the short pedistal under the terminal/CPU box.
	A 100Hz clock was included, as in the VT78 and PDP-8/A.

Expandability:  This was a closed system, with limited options.
	Specifically, a second RX02 could be connected (or an RX01,
	because that had a compatable connector), the DP278A and DP278B
	communications boards (really the same board, but the DP278B had
	2 extra chips), and the RL-278 disk controller, able to accomodate
	from 1 to 4 RL02 rack mount disk drives.

	When the DP278A option is added, additional routines in control
	memory come alive to handle terminal emulaton and allow diskless
	operation.  The terminal emulator is an extended VT100 subset
	that is essentially compatable in 80 column mode.  The DP278A
	option could support both asynchronous and synchronous protocols,
	and the DP278B could handle SDLC and other nasty bit-stuffing
	protocols.

	Various pedestal and desk configurations were sold for housing
	the RX01 and RX02 drives, most being teacart style designs, but
	there was also a pedestal version that was essentially a
	repackaging of the RX02 with either 2 or 4 new 8 inch disk
	transports (physically incompatable with earlier DEC transports).

Survival:  Many DECmates are still in use, and they are fairly common on
	the surplus market.  They are found in small numbers just about
	anywhere large numbers of early PC vintage machines are found.

------------------------------

Subject: What is a DECmate II?

Date of introduction:  1982
Date of withdrawal:    1986 
Price: $1,435

Technology:  Based on the 6120 microprocessor, this shared the same
	packaging as DEC's other competitors in the PC market, the
	Rainbow (8088 based) and the PRO-325 (PDP-11 based).

Reason for introduction:  This machine was introduced in order to allow
	more flexibility than the DECmate I and to allow more sharing of
	parts with the VT220 and DEC's other personal computers.

Compatability:  Same as the DECmate I, except it could continue from a
	halt.  There was better hardware for device emulation support,
	allowing for somewhat better real-time performance.  The data
	communications port was an incompatable improvement on the
	incompatable DECmate I communications port.  No built-in terminal
	emulation was provided, and the data communications port supported
	only one line, but aside from this, the data communications port
	is essentially as powerful as the DP-278B on the DECmate I.

Standard Configuration:  The DECmate II was sold with 32K of program
	memory, plus a second full bank for dedicated control panel
	function emulation.  Code running in the second bank is sometimes
	referred to as slushware; it looks like hardware to the PDP-8
	user, but it is actually device emulation software that is loaded
	from the boot diskette.

	An integral RX50 dual 5 1/4 inch diskette drive with an 8051
	controller chip was included, along with a printer port, a 100Hz
	real-time clock, single data communications port, and interfaces
	to the monitor and keyboard.  The diskette drive can read
	single-sided 48 track-per-inch diskettes, so it might be possible
	to read (but not write) IBM PC diskettes on it.

Expandability:  This was the most open of the DECmate systems, with a
	number of disk options:  An additional pair of RX50 drives could
	be added, and with the RX78 board, it could support a pair of
	dual 8 inch drives, either RX01 or RX02.

	As an alternative to the RX78, there was a controller for an
	MFM hard drive.  The interface to the RX78 board wasn't fully
	compatable with earlier interfaces to RX01 and RX02, and there
	was no way to have both an RX78 and an MFM drive.  The MFM drive
	could be up to 64 MB, with 16 sectors per track, 512 bytes each
	and at most 8 heads and 1024 (or possibly 4096) cylinders.  A
	power supply upgrade was needed to support the MFM drive.  DEC
	sold this machine with 5, 10 and 20 meg hard drives, Seagate
	ST-506, 412, and 225 respectively.

	A graphics board supporting a color monitor could be added in
	addition to the monochrome console display; two variants of
	this board were produced during the production run, all slightly
	incompatable.

	A coprocessor board could be added, with communication to and
	from the coprocessor through device 14.  DEC sold three boards,
	an APU board (Z80 and 64K), and two XPU boards (Z80, 8086 and
	either 256K or 512K).  If these added processors are used, the
	6120 processor is usually used as an I/O server for whatever
	ran on the coprocessor.  The XPU boards used a Z80 for I/O
	support, so 8086 I/O was very indirect, particularly if it
	involved I/O to a PDP-8 device that was emulated from control
	memory.  Despite this, the DECmate version of MS/DOS is generally
	faster than MS/DOS on more recent 80286 and 80386 based IBM PCs
	because of effective use of the coprocessors (but they couldn't
	run MS/DOS code that bypasses MS/DOS for I/O).

Survival:  As with the DECmate I.

------------------------------

Subject: What is a DECmate III?

Date of introduction:  1984
Date of withdrawal:    1990 
Price: $2,695

Technology:  Same as the DECmate II.

Reason for introduction:  Again, DEC discovered that the market for large
	systems was dominated by other products, and that the PDP-8 based
	products were rarely expanded to their full potential.  Thus,
	there was no point in paying the price for expandability.

Compatability:  Same as the DECmate II, except that the printer port is
	fixed at 4800 baud.

Standard Configuration:  The DECmate III was sold with 32K of program
	memory, plus a second full bank for dedicated control panel
	functions, an integral RX50 dual 5 1/4 inch diskette drive with
	an 8051 controller chip, a printer port, a 100Hz real-time-clock,
	a data communications port, and interfaces for the VR-201 monitor
	and keyboard.

Expandability:  A revised version of the Z80 based coprocessor for the
	DECmate II was available, and a graphics board largely compatable
	with the later DECmate II graphics board could be added allowing
	the standard monochrome monitor to be replaced with a VR-241 color
	monitor.  Two monitor configurations were not supported.  An
	obscure variant of the DEC scholar modem was also supported as
	an option.

Survival:  As with the DECmate I.

------------------------------

Subject: What is a DECmate III+?

Date of introduction:  1985
Date of withdrawal:    1990 

Technology:  Same as the DECmate II.

Reason for introduction:  This machine apparently represents the last
	gasp of the PDP-8, hunting for the remains of the ever-shrinking
	market niche that the earlier DECmates had carved out.  The
	market niche was not there, and the production runs for this
	machine were short enough that UV erasable EPROM technology was
	used where earlier DECmates had used mask programmed chips.

Compatability:  Same as the DECmate II, but the machine was unable to
	read 48 track per inch IBM formatted diskettes.  Again the
	printer port was fixed at 4800 baud.

Standard Configuration:  The DECmate III+ was sold with 32K of program
	memory, plus a second bank for dedicated control panel functions,
	an integral RX33 single 5 1/4 inch diskette drive with an 8751
	controller chip, a printer port, a data communications port and
	interfaces to the monitor and keyboard.  A hard disk controller
	compatable with the optional one on the DECmate II was included,
	supporting an integral ST-225 20 MB disk; it is likely that it
	can only handle up to 1024 cylinders, but it is otherwise
	compatable with the DECmate II.

Expandability: The same coprocessor option sold with the DECmate III was
	available, but because of the difficulty of adding a second floppy
	drive, this was rarely used (the Z80 was most likely to be used
	to run CP/M, but that system requires two drives to handle the
	installation procedure; an appropriately configured bootable
	image created on a DECmate II or III could run on a DECmate III+).

	The same graphics board as used on the DECmate III was also
	available.  The circuit traces and connectors for the Scholar
	modem are present, but this option was never sold on the
	DECmate III+.

Survival:  As with the other DECmates.

------------------------------

End of PDP-8 Summary of Models and Options (posted every other month)
*********************************************************************


From jones@cs.uiowa.edu Mon Aug  8 15:22:26 EDT 1994
Article: 986 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!rutgers!newsserver.jvnc.net!howland.reston.ans.net!math.ohio-state.edu!hobbes.physics.uiowa.edu!news.uiowa.edu!news
From: jones@cs.uiowa.edu (Douglas W. Jones)
Newsgroups: alt.sys.pdp8,alt.answers,news.answers
Subject: PDP-8 Frequently Asked Questions (posted every other month)
Followup-To: alt.sys.pdp8
Date: 8 Aug 94 08:08:08 GMT
Organization: Computer Science, University of Iowa, Iowa City, Iowa, USA
Lines: 1120
Approved: news-answers-request@MIT.Edu
Distribution: world
Expires: 8 Oct 1994 08:08:08 GMT
Message-ID: <325b0i$2kd@nexus.uiowa.edu>
NNTP-Posting-Host: herky.cs.uiowa.edu
Summary: Answers to common questions about antique DEC PDP-8 computers.
	Those posting to alt.sys.pdp8 should read this.
Keywords: FAQ DEC PDP 8
Xref: bigblue.oit.unc.edu alt.sys.pdp8:986 alt.answers:3806 news.answers:25313

Archive-name: dec-faq/pdp8
Last-modified: Aug 5, 1994

Frequently Asked Questions about the DEC PDP-8 computer.

	By Douglas Jones, jones@cs.uiowa.edu
	(with help from many folks)

The most recent version of this file is available by anonymous FTP from:

	ftp://rtfm.mit.edu/pub/usenet/alt.sys.pdp8
	ftp://ftp.uu.net/usenet/news.answers/dec-faq
	ftp://src.doc.ic.ac.uk:/pub/usenet/news.answers/alt.sys.pdp8
	ftp://sunsite.unc.edu/pub/academic/computer-science/history/pdp-8/docs

Automatic translations of this document to HTML format (as used by World Wide
Web) are available from:

	http://www.cis.ohio-state.edu/hypertext/faq/usenet/dec-faq/top.html

An obsolete version of this file is available on the Walnut Creek USENET
FAQ CDROM.

This posting conforms to RFC1153 USENET digest format (with exceptions due
to the fact that it is not really a digest).


Contents:

	What is a PDP?
	What is a PDP-8?
	What is the PDP-8 instruction set?
	What does PDP-8 assembly language look like?
	What character sets does the PDP-8 support?
	What different PDP-8 models were made?
	What about the LINC-8 and PDP-12?
	Where can I get a PDP-8 today?
	Where can I get PDP-8 documentation?
	What operating systems were written for the PDP-8?
	What programming languages were supported on the PDP-8?
	Where can I get PDP-8 software?
	Where can I get additional information?
	What use is a PDP-8 today?
	Who's Who?

----------------------------------------------------------------------

Subject: What is a PDP?

In 1957, Ken Olson and Harlan Anderson founded Digital Equipment
Corporation (DEC), capitalized at $100,000, and 70% owned by American
Research and Development Corporation.  The founders wanted to call the
company Digital Computer Corporation, but the venture capitalists
insisted that they avoid the term Computer and hold off on building
computers.  With facilities in an old woolen mill in Maynard
Massachusetts, DEC's first product was a line of transistorized digital
"systems modules", plug-in circuit boards with a few logic gates per
board.  Starting in 1960, DEC finally began to sell computers (the
formal acceptance of the first PDP-1 by BBN is reported in Computers
and Automation, April 1961, page 8B).  Soon after this, there were
enough users that DECUS, the Digital Equipment Computer User's Society
was founded.

DEC's first computer, the PDP-1, sold for only $120,000 at a time when
other computers sold for over $1,000,000.  (A good photo of a PDP-1 is
printed in Computers and Automation, Dec. 1961, page 27).  DEC quoted
prices as low as $85,000 for minimal models.  The venture capitalist's
insistance on avoiding the term computer was based on the stereotype
that computers were big and expensive, needing a computer center and a
large staff; by using the term Programmable Data Processor, or PDP, DEC
avoided this stereotype.  For over a decade, all digital computers sold
by DEC were called PDPs.  (In early DEC documentation, the plural form
"PDPs" is used as a generic term for all DEC computers.)

In the early 1960's, DEC was the only manufacturer of large computers
without a leasing plan.  IBM, Burroughs, CDC and other computer
manufacturers leased most of their machines, and many machines were
never offered for outright sale.  DEC's cash sales approach led to the
growth of third party computer leasing companies such as DELOS, a
spinoff of BB&N.

DEC built a number of different computers under the PDP label, with a
huge range of price and performance.  The largest of these are fully
worthy of large computer centers with big support staffs.  Some early
DEC computers were not really built by DEC.  With the PDP-3 and LINC,
for example, customers built the machines using DEC parts and
facilities.  Here is the list of PDP computers:

    MODEL  DATE  PRICE     BITS  COMMENTS
    =====  ====  ========  ====  =====
    PDP-1  1960  $120,000  18    DEC's first computer
    PDP-2            NA    24    Never built?
    PDP-3            NA    36    One built by a customer, not by DEC.
    PDP-4  1962   $60,000  18    Predecessor of the PDP-7.
    PDP-5  1963   $27,000  12    The ancestor of the PDP-8.
    PDP-6  1964  $300,000  36    A big computer; 23 built, most for MIT.
    PDP-7  1965   $72,000  18    Widely used for real-time control.
    PDP-8  1965   $18,500  12    The smallest and least expensive PDP.
    PDP-9  1966   $35,000  18    An upgrade of the PDP-7.
    PDP-10 1967  $110,000  36    A PDP-6 followup, great for timesharing.
    PDP-11 1970   $10,800  16    DEC's first and only 16 bit computer.
    PDP-12 1969   $27,900  12    A PDP-8 relative.
    PDP-13           NA          Bad luck, there was no such machine.
    PDP-14                       A ROM-based programmable controller.
    PDP-15 1970   $16,500  18    A TTL upgrade of the PDP-9.
    PDP-16 1972      NA    8/16  A register-transfer module system.

Corrections and additions to this list are welcome!  The prices given
are for minimal systems in the year the machine was first introduced.
The bits column indicates the word size.  Note that the DEC PDP-10
became the DECSYSTEM-20 as a result of marketing considerations, and
DEC's VAX series of machines began as the Virtual Address eXtension of
the never-produced PDP-11/78.

It is worth mentioning that it is generally accepted that the Data
General Nova (see photo, Computers and Automation, Nov. 1968, page 48)
was originally developed as the PDP-X, a 16-bit multi-register version
of the PDP-8.  A prototype PDP-X was built at DEC before the design was
rejected.  This and a competing 16-bit design were apparently submitted
to Harold McFarland at Carnegie-Mellon University for evaluation;
McFarland (and perhaps Gordon Bell, who was at C-MU at the time)
evaluated the competing designs and rejected both in favor of what we
know as the PDP-11.  Some speculate that Bell rejected the Nova design
because the competing proposal used the register-transfer notation he
had introduced in "Bell and Newell, Computer Structures -- Readings and
Examples".  An alternate story is that the reason DEC never produced a
PDP-13 was because the number 13 had been assigned to what became the
Nova; this is unlikely because the PDP-X prototype came before the -11.
Neither DEC nor Data General talk much about this, but Ed De Castro,
the founding president of Data General, was part of the PDP-8 design
team, as were many of the others who came to Data General to build the
Nova.

Today, all of the PDP machines are in DEC's corporate past, with the
exception of the PDP-11 family, which survives as a line of
microcomputers.

Of course, occasionally, some lab builds a machine out of DEC hardware
and calls it a PDP with a new number.  For example, the Australian
Atomic Energy Commission once upgraded a PDP-7 by adding a PDP-15 on
the side; they called the result a PDP-22.

------------------------------

Subject: What is a PDP-8?

The PDP-8 family of minicomputers were built by Digital Equipment
Corporation between 1965 and 1990, although it is worth noting that the
term minicomputer first came into prominence after the machine was
introduced.  The first use of the term appears to have been made by
the head of DEC's operations in England, John Leng.  He sent back a
sales report that started: "Here is the latest minicomputer activity
in the land of miniskirts as I drive around in my [Austin] Mini Minor."
The term quickly became part of DEC's internal jargon and spread from
there; the first computer explicitly sold as a minicomputer, though,
was made by by Interdata (See the Interdata ad in Computers and
Automation, May 1968, page 10).

The PDP-8 was largely upward compatible with the PDP-5, a machine that
was unveiled on August 11, 1963 at WESCON, and the inspiration for that
machine came from two earlier machines, the LINC and the CDC 160.  All
of these machines were characterized by a 12 bit word with little or no
hardware byte structure, typically 4K words of memory, and simple but
powerful instruction sets.

Although some people consider the CDC 160 the first minicomputer, the
PDP-8 was the definitive minicomputer.  By late 1973, the PDP-8 family
was the best selling computer in the world, and it is likely that it was
only displaced from this honor by the Apple II (which was displaced by
the IBM PC).  Most models of the PDP-8 set new records as the least
expensive computer on the market at the time of their introduction.
The PDP-8 has been described as the model-T of the computer industry
because it was the first computer to be mass produced at a cost that
just about anyone could afford.

C. Gordon Bell has said that the basic idea of the PDP-8 was not really
original with him.  He gives credit to Seymour Cray (of CDC and later
Cray) for the idea of a single-accumulator 12 bit minicomputer.  Cray's
CDC 160 family (see CACM, march 1961, photo on page 244, text on page
246) was such a machine, and in addition to the hundreds of CDC 160
systems sold as stand-alone machines, a derivative 12 bit architecture
was used for the I/O processors on Cray's first great supercomputer,
the CDC 6600.

Note that Cray's 12 bit machines had 6 basic addressing modes with
variable length instruction words and other features that were far from
the simple elegance of the PDP-8.  Despite its many modes, the CDC
architecture lacked the notion of current page addressing, and the
result is that, for examples that don't involve indexing, PDP-8 code is
generally as tight as and perhaps tighter than CDC 160 code.

------------------------------

Subject: What is the PDP-8 instruction set?

The PDP-8 word size is 12 bits, and the basic memory is 4K words.  The
minimal CPU contained the following registers:

	PC - the program counter, 12 bits.
	AC - the accumulator, 12 bits.
	L  - the link, 1 bit, commonly prefixed to AC as <L,AC>.

It is worth noting that many operations such as procedure linkage and
indexing, which are usually thought of as involving registers, are done
with memory on the PDP-8 family.

Instruction words are organized as follows:
	 _ _ _ _ _ _ _ _ _ _ _ _
	|_|_|_|_|_|_|_|_|_|_|_|_|
	|     | | |             |
	|  op |i|z|    addr     |

	op   - the opcode.
	i    - the indirect bit (0 = direct, 1 = indirect).
	z    - the page bit (0 = page zero, 1 = current page).
	addr - the word in page.

The top 5 bits of the 12 bit program counter give the current page, and
memory addressing is also complicated by the fact that absolute memory
locations 8 through 15 are incremented prior to use when used as indirect
addresses.  These locations are called auto-index registers (despite the
fact that they are in memory); they allow the formulation of very tightly
coded array operations.

The basic instructions are:

	000 - AND - and operand with AC.
	001 - TAD - add operand to <L,AC> (a 13 bit value).
	010 - ISZ - increment operand and skip if result is zero.
	011 - DCA - deposit AC in memory and clear AC.
	100 - JMS - jump to subroutine.
	101 - JMP - jump.
	110 - IOT - input/output transfer.
	111 - OPR - microcoded operations.

The ISZ and other skip instructions conditionally skip the next
instruction in sequence.  The ISZ is commonly used to increment a loop
counter and skip if done, and it is also used as an general increment
instruction, either followed by a no-op or in contexts where it is known
that the result will never be zero.

The JMS instruction stores the return address in relative word zero of
the subroutine, with execution starting with relative word one.
Subroutine return is done with an indirect JMP through the return
address.  Subroutines commonly increment their return addresses to index
through inline parameter lists or to perform conditional skips over
instructions following the call.

The IOT instruction has the following form:
	 _ _ _ _ _ _ _ _ _ _ _ _
	|1|1|0|_|_|_|_|_|_|_|_|_|
	|     |           |     |
	|     |   device  | op  |

The IOT instruction specifies one of up to 8 operations on one of 64
devices.  Typically (but not universally), each bit of the op field
evokes an operation, and these can be microcoded in right to left
order.  Prior to the PDP-8/E, there were severe restrictions on the
interpretation of the op field that resulted from the fact that the
operation was delivered as a sequence of IOP pulses, each on a separate
line of the I/O bus.  Each line was typically used to evoke a different
device function, so essentially, the operation 000 was always a no-op
because it evoked no functions, and the code 111 evoked all three
functions in series.

As an example of the use of IOT instructions, consider the console
terminal interface.  On early PDP-8 systems, this was always assumed to
be an ASR 33 teletype, complete with low-speed paper tape reader and
punch.  It was addressed as devices 03 (the keyboard/reader) and 04
(the teleprinter/punch):
	 _ _ _ _ _ _ _ _ _ _ _ _
	|1|1|0|_|_|_|_|_|_|_|_|_|
	      |0 0 0 0 1 1|0 0 1  - KSF - keyboard skip if flag
	      |0 0 0 0 1 1|0 1 0  - KCC - keyboard clear flag
	      |0 0 0 0 1 1|1 0 0  - KRS - keyboard read static

The keyboard flag is set by the arrival of a character.  The KCC
instruction clears both the flag and the accumulator.  KRS ors the 8 bit
input data with the low order 8 bits of AC.  The commonly used KRB
instruction is the or of KCC and KRS.  To await one byte of input, use
KSF to poll the flag, then read the byte with KRB.
	 _ _ _ _ _ _ _ _ _ _ _ _
	|1|1|0|_|_|_|_|_|_|_|_|_|
	      |0 0 0 1 0 0|0 0 1  - TSF - teleprinter skip if flag
	      |0 0 0 1 0 0|0 1 0  - TCF - teleprinter clear flag
	      |0 0 0 1 0 0|1 0 0  - TPC - teleprinter print static

The teleprinter flag is set by the completion of the TPC operation (as
a result, on startup, many applications output a null in order to get
things going).  TCF clears the flag, and TPC outputs the low order 8
bits of the accumulator.  The commonly used TLS instruction is the or
of TCF and TPC.  To output a character, first use TSF to poll the flag,
then write the character with TLS.

IOT instructions may be used to initiate data break transfers from block
devices such as disk or tape.  The term "data break" was, for years,
DEC's preferred term for cycle-stealing direct-memory-access data
transfers.

Some CPU functions are accessed only by IOT instructions.  For example,
interrupt enable and disable are IOT instructions:
	 _ _ _ _ _ _ _ _ _ _ _ _
	|1|1|0|_|_|_|_|_|_|_|_|_|
	      |0 0 0 0 0 0|0 0 1  - ION - interrupts turn on
	      |0 0 0 0 0 0|0 1 0  - IOF - interrupts turn off

An interrupt is requested when any device raised its flag.  The console
master clear switch resets all flags and disables interrupts.  In
effect, an interrupt is a JMS instruction to location zero, with the
side effect of disabling interrupts.  The interrupt service routine
is expected to test the device flags and perform the operations needed
to reset them, and then return using ION immediately before the indirect
return JMP.  The effect of ION is delayed so that interrupts are not
enabled until after the JMP.

The instructions controlling the optional memory management unit are
also IOT instructions.  This unit allows the program to address up to
32K of main memory by adding a 3 bit extension to the memory address.
Two extensions are available, one for instruction fetch and direct
addressing, the other for indirect addressing.

A wide variety of operations are available through the OPR microcoded
instructions:
         _ _ _ _ _ _ _ _ _ _ _ _
Group 1 |1|1|1|0|_|_|_|_|_|_|_|_|
	         1                - CLA - clear AC
	           1              - CLL - clear the L bit
                     1            - CMA - ones complement AC
                       1          - CML - complement L bit
                               1  - IAC - increment <L,AC>
                         1 0 0    - RAR - rotate <L,AC> right
                         0 1 0    - RAL - rotate <L,AC> left
	                 1 0 1    - RTR - rotate <L,AC> right twice
	                 0 1 1    - RTL - rotate <L,AC> left twice

In general, the above operations can be combined by oring the bit
patterns for the desired operations into a single instruction.  If none
of the bits are set, the result is the NOP instruction.  When these
operations are combined, they operate top to bottom in the order shown
above.  The exception to this is that IAC cannot be combined with the
rotate operations on some models, and attempts to combine rotate
operations have different effects from one model to another (for example,
on the PDP-8/E, the rotate code 001 means swap 6 bit bytes in the
accumulator, while previous models took this to mean something like
"shift neither left nor right 2 bits").
         _ _ _ _ _ _ _ _ _ _ _ _
Group 2 |1|1|1|1|_|_|_|_|_|_|_|0|
                   1     0        - SMA - skip on AC < 0  \
                     1   0        - SZA - skip on AC = 0   > or group
                       1 0        - SNL - skip on L /= 0  /
                   0 0 0 1        - SKP - skip unconditionally
                   1     1        - SPA - skip on AC >= 0 \
                     1   1        - SNA - skip on AC /= 0  > and group
                       1 1        - SZL - skip on L = 0   /
                 1                - CLA - clear AC
                           1      - OSR - or switches with AC
                             1    - HLT - halt

The above operations may be combined by oring them together, except that
there are two distinct incompatible groups of skip instructions.  When
combined, SMA, SZA and SNL, skip if one or the other of the indicated
conditions are true (logical or), while SPA, SNA and SZL skip if all of
the indicated conditions are true (logical and).  When combined, these
operate top to bottom in the order shown; thus, the accumulator may be
tested and then cleared.  Setting the halt bit in a skip instruction is
a crude but useful way to set a breakpoint for front-panel debugging.
If none of the bits are set, the result is an alternative form of no-op.

A third group of operate microinstructions (with a 1 in the least
significant bit) deals with the optional extended arithmetic element to
allow such things as hardware multiply and divide, 24 bit shift
operations, and normalize.  These operations involve an additional data
register, MQ or multiplier quotient, and a small step count register.
On the PDP-8/E and successors, MQ and the instructions for loading and
storing it were always present, even when the EAE was absent, and the
EAE was extended to provide a useful variety of 24 bit arithmetic
operations.

------------------------------

Subject: What does PDP-8 assembly language look like?

There are many different assemblers for the PDP-8, but most use a
compatible basic syntax; here is an example:

	START,	CLA CLL		/ Clear everything
		TAD	X	/ Load X
		AND I	Y	/ And with the value pointed to by Y
		DCA	X	/ Store in X
		HLT		/ Halt

	X,	1 		/ A variable
	Y,	7 		/ A pointer

Note that labels are terminated by a comma, and comments are separated
from the code by a slash.  There are no fixed fields or column
restrictions.  The "CLA CLL" instruction on the first line is an example
of the microcoding of two of the Group 1 operate instructions.  CLA
alone has the code 7200 (octal), while CLL has the code 7100; combining
these as "CLA CLL" produces 7300.  As a general rule, except when memory
reference instructions are involved, the assembler simply ors together
the values of all blank separated fields between the label and comment.
	
Indirection is indicated by the special symbol I in the operand field,
as in the third line of the example.  The typical PDP-8 assembler has no
explicit notation to distinguish between page zero and current page
addresses.  Instead, the assembler is expected to note the page holding
the operand and automatically generate the appropriate mode.  If the
operand is neither in the current page nor page zero, some assemblers
will raise an error, others will automatically generate an indirect
pointer to the off-page operand; this should be avoided because it only
works for directly addressed off-page operands, and only when the memory
management unit is not being used to address a data field other than the
current instruction field.

Note, in the final two lines of the example, that there is no "define
constant" pseudo-operation.  Instead, where a constant is to be
assembled into memory, the constant takes the place of the op-code field.

The PDP-8 has no immediate addressing mode, but most assemblers provide
a notation to allow the programmer to ignore this lack:

		TAD	(3)	/ add 3, from memory on the current page.
		TAD	[5]	/ add 5, from memory on page zero.
		JMP I	(LAB)	/ jump indirect through the address of LAB.

Assemblers that support this automatically fill the end of each page
with constants defined in this way that have been accumulated during the
assembly of that page.  Note that the variants "(3" and "[5" (with no
closing parentheses) are usually allowed but the use of this sloppy form
is discouraged.  Furthermore, the widely used PAL8 assembler interprets
the unlikely operand "(3)+1" as being the same as "(3+1)".

Arithmetic is allowed in operand fields and constant definitions, with
expressions evaluated in strict left-to-right order, as:

		TAD	X+1	/ add the contents of the location after X.
		TAD	(X-1)	/ add the address of the location before X.

Other operators allowed include and (&), or (!), multiply (^) and divide
(%), as well as a unary sign (+ or -).  Unfortunately, one of the most
widely used assemblers, PAL8, has trouble when unary operators are mixed
with multiplication or division.
	
Generally, only the first 6 characters of identifiers are significant
and numeric constants are evaluated in octal.

Other assembly language features are illustrated below:

	/ Comments may stand on lines by themselves
				/ Blank lines are allowed

		*200		/ Set the assembly origin to 200 (octal)

	NL0002=	CLA CLL CML RTL	/ Define new opcode NL0002.

		NL0002		/ Use new opcode (load 0002 in AC)
		JMP	.-1	/ Jump to the previous instruction

	X1=	10		/ Define X1 (an auto-index register address)
	LETA=	"A		/ Define LETA as 000011000001 (ASCII A)

		TAD I	X1	/ Use autoindex register 1

		IAC; RAL	/ Multiple instructions on one line

		$		/ End of assembly

The assembly file ends with a line containing a $ (dollar sign) not in
a comment field.

The $, * and =  syntax used by most PDP-8 assemblers replaces functions
performed by pseudo-operations on many other assemblers.  In addition,
PAL8, the most widely used PDP-8 assembler supports the following
pseudo-operations:

		DECIMAL		/ Interpret numeric constants in base 10
		OCTAL		/ Interpret numeric constants in base 8
		EJECT		/ Force a page eject in the listing
		XLIST		/ Toggle listing
		XLIST	N	/ Turn on listing if N=0, off if N=1
		PAGE 	 	/ Advance location counter to next page
		PAGE 	N	/ Set location counter start of page N
		FIELD	N	/ Assemble into extended memory field N
		TEXT	"STR"	/ Pack STR into consecutive 6 bit bytes
		ZBLOCK	N	/ Allocate N words, initialized to zero
		IFDEF	S <C>	/ Assemble C if symbol S is defined
		IFNDEF	S <C>	/ Assemble C if symbol S is not defined
		IFZERO	E <C>	/ Assemble C if expression E is zero
		IFNZRO	E <C>	/ Assemble C if expression E is not zero
		FIXMRI  OP= VAL	/ Define OP as memory reference instruction

Conditonally assembled code must be enclosed in angle brackets.  The
enclosed code may extend over multiple lines and, because different
assemblers treat comments within conditionals differently, the closing
bracket should not be in a comment and any brackets in comments should
be balanced.

------------------------------

Subject: What character sets does the PDP-8 support?

From the beginning, PDP-8 software has generally assumed that textual
I/O would be in 7 bit ASCII.  Most early PDP-8 systems used teletypes
as console terminals; as sold by DEC, these were configured for mark
parity, so most older software assumes 7 bit ASCII, upper case only,
with the 8th bit set to 1.  On output, lines are generally terminated
with both CR and LF; on input, CR is typically (but not always) the
line terminator and LF is typically ignored.  In addition, the tab
character (HT) is generally allowed, but software support output of text
containing tabs varies.

One difficulty with much PDP-8 software is that it bypasses the device
handlers provided by the operating system and goes directly to the
device.  This results in very irregular device support, so that, for
example, control-S and control-Q work to start and stop output under
OS/8, but the OS/8 PAL assembler ignores them when reporting errors.

Most of the better engineered PDP-8 software tends to fold upper and
lower case on input, and it ignores the setting of the 8th bit.  Older
PDP-8 software will generally fail when presented with lower case
textual input (this includes essentially all OS/8 products prior to
OS/278 V1).

Internally, PDP-8 programmers are free to use other character sets, but
the "X notation provided by the assembler encourages use of 7 bit ASCII
with the 8th bit set to 1, and the TEXT pseudo-operation encourages the
6 bit character set called "stripped ASCII".  To map from upper-case-only
ASCII to stripped ASCII, each 8 bit character is anded with octal 77 and
then packed 2 characters per word, left to right.  Many programs use a
semi-standard scheme for packing mixed upper and lower case into 6 bit
TEXT form; this uses ^ to flip from upper to lower case or lower to
upper case, % to encode CR-LF pairs, and @ (octal 00) to mark end of
string.  Note that this scheme makes no provision for encoding the %,
^ and @ characters, nor does it allow control characters other than the
CR-LF pair.

The P?S/8 operating system supports a similar 6 bit text file format,
where upper and lower case are folded together, tabs are stored as _
(underline), end-of-line is represented by 00, padded with any
nonzero filler to a word boundary, and end of file is 0000.

Files under the widely used OS/8 system consist of sequences of 256 word
blocks.  When used for text, each block holds 384 bytes, packed 3 bytes
per pair of words as follows:

		aaaaaaaa		ccccaaaaaaaa
		bbbbbbbb		CCCCbbbbbbbb
		ccccCCCC

Control Z is used as an end of file marker.  Because most of the PDP-8
system software was originally developed for paper tape, binary object
code is typically stored in paper-tape image form using the above packing
scheme.

------------------------------

Subject: What different PDP-8 models were made?

The total sales figure for the PDP-8 family is estimated at over 300,000
machines.  Over 7000 of these were sold prior to 1970.  During the PDP-8
production run, a number of models were made, as listed in the following
table.  Of these, the PDP-8/E is generally considered to be the
definitive machine.  If the PDP-8 is considered to be the Model T of the
computer industry, perhaps the PDP-8/E should be considered to be the
industry's Model A.

    MODEL	DATES	SALES   COST	TECHNOLOGY	REMARKS

    PDP-5	63-67	 116		Transistor
    PDP-8	65-69 	1450	$18,500	Transistor
    LINC-8	66-69	 142	$38,500	Transistor
    PDP-8/S	66-70	1024	$10,000	Transistor	Very slow
    PDP-8/I	68-71 	3698	$12,800	TTL
    PDP-8/L	68-71 	3902	 $8,500	TTL		Scaled down 8/I
    PDP-12	69-73?	3500?	$27,900	TTL		Followup to LINC-8
    PDP-8/E	70-78	>10K?	 $7,390	TTL MSI	Omnibus
    PDP-8/F	72-78?	>10K?	<$7K	TTL MSI Omnibus	Based on 8/E CPU
    PDP-8/M	72-78?	>10K?	<$7K	TTL MSI Omnibus	OEM version of 8/F
    PDP-8/A	75-84?	>10K?	 $1,317	TTL LSI Omnibus	New CPU or 8/E CPU
    VT78	78-80		<$10K	Harris 6120	Workstation
    DECmate I	80-84			Harris 6120	Workstation
    DECmate II	82-86		 $1,435	Harris 6120	Workstation
    DECmate III	84-90		 $2,695	Harris 6120	Workstation
    DECmate III+85-90			Harris 6120	Workstation

Additional information is available in part two of this FAQ, where all
known models of the PDP-8, along with variants, alternate marketing
names, and other peculiarities are given.

The last years of the PDP-8 family were dominated by the PDP-8 compatible
microprocessor based VT78 and DECmate workstations.  DEC also used the
Harris 6120 microprocessors in many peripheral controllers for the
PDP-11 and PDP-15.  While all of the earlier PDP-8 systems were open
architecture systems, the DECmates had closed architectures with an
integrated console terminals and limited peripheral options.

The following PDP-8 compatible or semi-compatible machines were made and
sold by others; very little is known about many of these:

	MODEL		DATE	MAKER, NOTES

	MP-12		6?	Fabritek (a surviving example runs FOCAL).
	TPA		68?	Hungarian, a PDP-8/L clone, ran FOKAL
	Electrotechnica-100I ?	Yugoslavian, a PDP-8/I clone or OEM label.
	Saratov-2	?	Russian, a slow clone, perhaps PDP-8/S
	Voronezh	?	Russian, another PDP-8/? clone
	SPEAR u-LINC 100?	SPEAR, Inc, Waltham Mass (a LINC clone!)
	SPEAR u-LINC 300?	SPEAR, Inc, Waltham Mass (a LINC clone!)
	DCC-112		70-71	Digital Computer Controls
	DCC-112H	71	Digital Computer Controls
	6100 Sampler	7?	Intersil, their IM6100 promotional kit
	Intercept I	7?	Intersil, based on IM6100
	Intercept Jr	7?	Intersil, based on IM6100
	PCM-12		7?	Pacific CyberMetrix, based on Intercept bus
	PCM-12A		7?	Pacific CyberMetrix, fixed to clock at 4MHz
	SBC-8		84-88	CESI, Based on IM6120, SCSI bus
	
------------------------------

Subject: What about the LINC/8 and PDP-12?

Wesley Clark, then at Lincoln Labs, developed the LINC, or Laboratory
INstrumentation Computer, as a personal laboratory computer in the
early 1960's.  He developed it in response to the needs of Mary Brazier,
a neurophysiologist at MIT who needed better laboratory tools.  Over 24
LINC systems were built by customers before late 1964 when DEC began
selling a commercial version (see Computers and Automation, Nov. 1964,
page 43).  By the time DEC introduced the LINC-8, 43 LINC systems had
been installed (see Computers and Automation, Mar. 1966, page 34).

When Lincoln Labs decided that the LINC did not fit their mission, a
group at the the National Institute of Health funded an experiment to
see if the LINC would be a productive tool in the life sciences.  As a
result of this project, 12 LINCs were built and debugged, each by its
eventual user.

The LINC was the first 12 bit minicomputer built using DEC hardware.
Like the PDP-5 and other early DEC computers, it was built with system
modules, DEC's first family of logic modules.  Along with the CDC 160,
it paved the way for the PDP-5 and PDP-8.

When compared with the PDP-8, the LINC instruction set was not as well
suited for general purpose computation, but the common peripherals
needed for lab work such as analog-to-digital and digital-to-analog
converters were all bundled into the LINC system.  Users judged it to
be a superb laboratory instrument.

One of the major innovations introduced with the LINC was the LINCtape.
These tapes could be carelessly pocketed or dropped on the floor
without fear of data loss, and they allowed random access to data
blocks.  DEC improved on this idea slightly to make their DECtape
format, and DECtape was widely used with all DEC computers made in the
late 1960's and early 1970's.

The motives behind the development of LINCtape were the same motives
that led IBM to develop the floppy disk almost a decade later, and in
fact, DECtape survived as a widely used medium until DEC introduced the
RX01 8 inch floppy disk drive around 1975, and even after this, DECtape
was only slowly phased out.

Within a year of the introduction of the PDP-8, DEC released the LINC-8,
a machine that combined a PDP-8 with a LINC in one package.  The
success of the LINC-8 led DEC to re-engineer the machine using TTL
logic in the late 1960's; the new version was originally to be called
the LINC-8/I, but it was sold as the PDP-12.  Both the LINC-8 and the
PDP-12 had impressive consoles, with separate sets of lights and
switches for the LINC and PDP-8 halves.

The success of the LINC-8 also led to the development of a clone, the
SPEAR micro-LINC.  This machine used Motorola MECL integrated circuits
and was available for delivery in (June 1965? this date must be wrong!).

The LINC-8 and PDP-12 could run essentially any PDP-8 or LINC program,
with the exception of the few programs that relied on the primitive
interrupt structure of the original LINC architecture; on the LINC-8,
all interrupts were handled by the PDP-8 side of the hardware.  Because
the LINC-8 and PDP-12 had instructions for switching between modes, a
new body of software was developed that required both modes.

One feature of LINC and LINC-8 software is the common use of the graphic
display for input-output.  These machines were some of the first to
include such a display as a standard component, and many programs used
the knobs on the analog to digital converter to move a cursor on the
display in the way we now use a mouse.

Various versions of LAP, the Linc Assembly Program, were the dominant
assemblers used on the LINC.  WISAL (WISconson Assembly Language) or
LAP6-W was the version of this assembler that survived to run on the
PDP-12.  Curiously, this includes a PDP-8 assembler written in LINC code.

LAP6-DIAL (Display Interactive Assembly Language) evolved from this on
the PDP-12 to became the dominant operating system for the PDP-12.  The
8K version of this is DIAL MS (Mass Storage), even if it has only two
LINCtape drives.  These were eventually displaced by the OS/8 variant
known as OS/12.

------------------------------

Subject: Where can I get a PDP-8 today?

The CESI machine may still be on the market, for a high price, but
generally, you can't buy a new PDP-8 anymore.  There are quite a few
PDP-8 machines to be found in odd places on the used equipment market.
They were widely incorporated into products such as computer controlled
machine tools, X-ray diffraction machines, and other industrial and lab
equipment.  Many of them were sold under the EduSystem marketing
program to public schools and universities, and others were used to
control laboratory instrumentation.  After about 1976, Reuters bought
as many as 10,000 OMNIBUS based machines per year, with perhaps 2000 per
year going to other customers.

If you can't get real hardware, you can get emulators.  Over the years,
many PDP-8 emulators have been written; the best of these are
indistinguishable from the real machine from a software prespective,
and on a modern high-speed RISC platform, these frequently outperform
the hardware they are emulating.  Emulators are available from:

  ftp://sunsite.unc.edu/pub/academic/computer-science/history/pdp-8/emulators

Finally, you can always build your own.  The textbook "The Art of
Digital Design," second edition, by Franklin Prosser and David Winkel
(Prentice-Hall, 1987, ISBN 0-13-046780-4) uses the design of a PDP-8 as
a running example.  Many students who have used this book were required
to build working PDP-8 systems as lab projects.

------------------------------

Subject: Where can I get PDP-8 documentation?

Part II of this FAQ cites the key documents published by DEC describing
each model of the PDP-8.  These are all out of print, and DEC was in the
habit of printing much of their documentation on newsprint with
paperback bindings, which is to say, surviving copies tend to be yellow
and brittle.  DEC distributed huge numbers of catalogs and programming
handbooks in this inexpensive paperback format, and these circulate
widely on the second-hand market.  When research laboratories and
electronics shops are being cleaned out, it is still common to find a
few dusty, yellowed copies of these books being thrown out.

Douglas Jones has made a small number of bound photocopies of DEC's
1973 introduction to programming, perhaps the definitive introduction
to the PDP-8, and the other early DEC handbooks need similar treatment
before they all crumble.

Maintenance manuals are harder to find, but more valuable.  If you need
one, you usually need to find someone willing to photocopy one of the
few surviving copies.  DEC has been friendly to collectors, granting
fairly broad letters of permission to reprint obsolete documentation,
and the network makes if fairly easy to find someone who has the
documentation you need and can get copies.  The most difficult to copy
material is the large prints, many of which would be quite useful if
photoreduced, but this is expensive.

------------------------------

Subject: What operating systems were written for the PDP-8?

A punched paper-tape library of stand-alone programs was commonly used
with the smallest (diskless and tapeless) configurations from the
beginning up through the mid 1970's.  This included a paper-tape based
text editor, the PAL III and MACRO-8 assembler, and a FORTRAN compiler,
as well as a library of support routines.  Many paper tapes from this
library survive to the present at various sites!  The minimum
configuration expected by these tapes is a CPU with 4K memory and a
teletype ASR 33 with paper tape reader and punch.  Note that much of this
paper-tape-based software is based on memory-use and I/O conventions that
are incompatible with later disk-based systems.

The DECtape Library System was a DECtape oriented save and restore system
that was available from the start.  The resident portion of this system
occupies only 17 words of memory (7600-7625 octal), and it allowed saving
and restoring absolute core images as named files on a reel of DECtape.
Initially, program development was still done with paper tape, and only
executable memory images were stored on DECtape, but eventually, a limited
DECtape-based text editor was introduced, along with a DECtape based
assembler.

The 4K Disk Monitor System provided slightly better facilities.  This
supported on-line program development and it worked with any device that
supported 129 word blocks (DECtape, the DF32 disk, or the RF08 disk).
It was quite slow, but it also used very little of the available memory.

MS/8 or the R-L Monitor System, was developed starting in 1966 and
submitted to DECUS in 1970.  This was a disk oriented system, faster than
the above, with tricks to make it run quickly on DECtape based systems.

POLY BASIC was a BASIC only system submitted to DECUS and later sold by
DEC as part of its EduSystem marketing program.  EduSystem 25 Basic
is available from:

	ftp://nickel.ucs.indiana.edu/pub/DEC/PDP8/Langs/Edu25Basic

P?S/8 was developed starting in 1971 from an MS/8 foundation.  It runs
on minimal PDP-8 configurations, supports somewhat device independant
I/O and requires a random-access device for the file system (DECtape is
random-access!).  P?S/8 runs compatibly on most PDP-8 machines including
DECmates, excepting only the PDP-8/S and PDP-5.  P?S/8 is still being
developed!

OS/8, developed in parallel with P?S/8, became the main PDP-8 programming
environment sold by DEC.  The minimum configuration required was 8K words
and a random-access device to hold the system.  For some devices, OS/8
requires 12K.  There are a large number of OS/8 versions that are not
quite portable across various subsets of the PDP-8 family.  OS/8 V3D was
renamed OS/78 (to match the VT78), and by the time OS/78 V3 was released,
support for Omnibus machines was no longer important.  OS/78 V4 was
developed for the DECmate I, and the name OS/278 used for the versions
released with later DECmate machines.  These have unnecessary
incompatabilities with earlier versions of OS/8.  OS/278 and related
material is available from:

	ftp://ftp.telebit.com/pub/pdp8/os278
	ftp://ftp.update.uu.se/pub/pdp8
	ftp://sunsite.unc.edu/pub/academic/computer-science/history/pdp-8/os8

OS8 (no slash) may still be viable.  It requires 8K of main memory, an
extended arithmetic unit, and DECtape hardware.  Unlike most PDP-8
operating systems, it uses a directory structure on DECtape compatible
with that used on the PDP-10.

TSS/8 was developed in 1968 as a timesharing system.  It required a
minimum of 12K words of memory and a swapping device.  It was the
standard operating system on the EduSystem 50 which was sold to many
small colleges and large public school systems.  Each user gets a
virtual 4K PDP-8; many of the utilities users ran on these virtual
machines were only slightly modified versions of utilities from the
Disk Monitor System or paper-tape environments.

Other timesharing systems developed for the PDP-8 include MULTI-8, ETOS,
MULTOS, and OMNI-8; some of these required nonstandard memory management
hardware.  By the mid 1970's, some of these were true virtual machine
operating systems in the same spirit as IBM's VM-370; they typically
supported some version of OS/8 running on a 32K virtual PDP-8 assigned
to each user.  Some could support different user operating systems on
each virtual machine, others supported addressing of more than 4K for
data, but limited code to field zero of a process's virtual memory.
The source for MULTOS is available from:

	ftp://ftp.update.uu.se/pub/pdp8/multos8

CAPS-8 was a cassette based operating system supporting PAL and BASIC.
There are OS/8 utilities to manipulate CAPS-8 cassettes, and the file
format on cassette is compatible with a PDP-11 based system called
CAPS-11.

RTS/8 was a real-time system developed by DEC, developed from an earlier
system, SRT8, dating back to at least 1974.  Curiously, even the last
versions of RTS/8 continued to support paper-tape and DECtape.  Source
code for most of the versions of RTS and SRT are available from:

	ftp://sunsite.unc.edu/pub/academic/computer-science/history/pdp-8/rts8

WPS was DEC's word processing system, developed for the 8/E with a VT50
terminal with special WPS keycaps replacing the standard keycaps, and
widely used on the 1980's vintage machines.  It was heavily promoted on
the VT-78, and when the DECmates came out, DEC began to suppress knowledge
that DECmates could run anything else.  WPS-11 was a curious distributed
system using a PDP-11 as a file server for a cluster of VT-78 WPS systems.

COS-310, DEC's commercial operating system for the PDP-8, supported the
DIBOL language.  COS-310 was a derivative of MS/8 and OS/8, but with a
new text file format.  The file system is almost the same as OS/8, but
dates are recorded differently, and a few applications can even run under
both COS and OS/8.  COS was the last operating system other than WPS
promoted by DEC for the DECmates.

------------------------------

Subject: What programming languages are supported on the PDP-8

The PAL family of assembly languages, particularly PAL III and PAL8 are
as close to a standard assembly language as can be found for the PDP-8.
These produce absolute object code and there are versions of PAL for
minimally configured machines, although these have severe symbol table
limitations.

MACRO-8 was DEC's first macro assembly language for the PDP-8, but it
was rarely used outside the paper-tape environment.  MACREL and SABR are
assembly languages that produce relocatable output.  SABR is the final
pass for the ALICS II FORTRAN compiler (developed by ICS), and MACREL
was developed in (unfulfilled) anticipation of similar use.  MACREL was
heavily used by the DECmate group at DEC.  MACREL is available from

	ftp://ftp.update.uu.se/pub/pdp8/os8

There was also RALF, the relocatable assembler supporting RTPS FORTRAN,
and FLAP, an absolute assembler derived from RALF.  Both SABR and
RALF/FALP are assemblers that handle their intended applications but
have quirky and incompatible syntax.

A subset of FORTRAN was supported on both the PDP-5 and the original
PDP-8.  Surviving documentation describes a DEC compiler from 1964 and
a compiler written by Information Control Systems from 1968.  The
latter, ALICS II FORTRAN, was originally a paper tape based compiler,
but it forms the basis of the OS/8 8K FORTRAN compiler, and was also
adapted to the Disk Monitor System (the latter version had overlay
support that was never carried forward into more modern systems).

RTPS FORTRAN required 8K and a floating point processor; it had real-time
extensions and was a full implementation of FORTRAN IV (also known as
ANSI FORTRAN 66).  OS/8 F4 is RTPS FORTRAN stripped of the requirement
for hardware floating point (if the hardware is missing, it uses
software emulation).  A version of FORTRAN is available from

	ftp://ftp.update.uu.se/pub/pdp8/os8

FOCAL, an interpretive language comparable to BASIC, was available on
all models of the family, including the PDP-5 and PDP-8/S.  Versions of
FOCAL run under OS/8, P?S/8 and other systems, and there were many special
purpose overlays for FOCAL developed by DEC and by various users.  DEC's
later FOCAL releases for the PDP-8 included code to deliberately introduce
subtle bugs when run on a DCC 112 computer!  Various versions of FOCAL
are available from:

	ftp://nickel.ucs.indiana.edu/pub/DEC/PDP8/Langs/Focal

Many versions of BASIC were also available, from DEC and other sources.
DEC BASIC was widely used on PDP-8 systems sold under the EduSystem
marketing program.  A paper-tape version was available that ran in 4K
and was compatible with disk based systems, versions were developed for
OS/8 and TSS/8, an 8K stand-alone time-sharing version was available,
and there were others.  EduSystem 25 Basic is available from:

	ftp://nickel.ucs.indiana.edu/pub/DEC/PDP8/Langs/Edu25Basic

DIBOL was DEC's attempt at competing with COBOL in the commercial arena.
It was originally implemented under MS/8 but most versions were sold to
run under the COS operating system.

Algol was available from a fairly early date.  One version is available
from:

	ftp://nickel.ucs.indiana.edu/pub/DEC/PDP8/Langs/Algol

At least two Pascal compilers were developed for the PDP-8.  One was a
Pascal-S interpreter, written in assembler, the other was a Pascal-P
compiler with a P-code interpreter written in assembler.

A LISP interpreters was written for the PDP-8; the original version
ran in 4K (originally written in Germany?); a disassembled and commented
version of this was the basis of expanded versions that eventually
could utilize up to 16K.  One version of LISP is available from:

	ftp://nickel.ucs.indiana.edu/pub/DEC/PDP8/Langs/Lisp

A Pascal S interpreter, requiring a 28K PDP-8/E configuration, is available
from:

	ftp://nickel.ucs.indiana.edu/pub/DEC/PDP8/Langs/Pascal

POLY SNOBOL was a version of SNOBOL that was somewhere between
Griswold's definitions of SNOBOL 3 and SNOBOL 4.

TECO, the text editor, is available, and is also a general purpose
language, and someone is working on a PDP-8 C.  The story of TECO on the
PDP-8 is convoluted.  Russ Ham implemented TECO under his OS8 (without
a slash) system.  This version of TECO was pirated by the Oregon Museum
of Science and Industry (OMSI), where the system was ported to PS/8.
Richard Lary and Stan Rabinowitz made it more compatible with other
versions of TECO, and the result of this work is the version distributed
by DECUS.  RT-11 TECO for the PDP-11 is a port of this code.

------------------------------

Subject: Where can I get PDP-8 software?

DECUS, the DEC User Society, is still alive and well, and their submission
form still lists PAL8 and FOCAL as languages in which they accept
submissions!  The DECUS library catalog is available on-line by
anonymous FTP at decus.org (but note, www cannot access this site!).

To quote the README file from the current on-line catalog, "Items from
older DECUS Library catalogs are still also available (provided their
media can still be read), but machine readable catalog information is
not available for these."  Direct questions by E-mail to
INFORMATION@DECUS.ORG.

The following anonymous FTP sites contain publically accessable archives
of PDP-8 software and other information:

	ftp://ftp.telebit.com/pub/pdp8
	ftp://ftp.update.uu.se/pub/pdp8
	ftp://nickel.ucs.indiana.edu/pub/DEC/PDP8
	ftp://sunsite.unc.edu/pub/academic/computer-science/history/pdp-8

The latter archive also maintains an archive of traffic in alt.sys.pdp8
in the directory ...pdp8/usenet and an archive of traffic in the
pdp8-lovers mailing list in .../pdp8/pdp8-lovers.

The archive at Indiana contains source code for many PDP-8 compilers and
interpreters, as well as common utilities and games.

------------------------------

Subject: Where can I get additional information?

The file WHAT-IS-A-PDP8, by Charles Lasner contains considerable
additional information; this file is available by ftp from:

	ftp://ftp.telebit.com/pub/pdp8/WHAT-IS-A-PDP8

This file gives details of every PDP-8 model including the small quirks
and incompatabilities that (to be generous) allow software to determine
which model it is running on.  These quirks also make it all too easy
for careless programmers to write almost portable software with very
obscure bugs.

The mailing list pdp8-lovers@ai.mit.edu reaches a number of PDP-8 owners
and users, not all of whom have USENET feeds.  The USENET newsgroup
alt.sys.pdp8 needs to be gatewayed to this mailing list.

Many "archival" books have included fairly complete descriptions of the
PDP-8; among them, "Computer Architecture, Readings and Examples" by
Gordon Bell and Allen Newell is among the most accurate and complete
(but difficult to read).

------------------------------

Subject: What use is a PDP-8 today?

What use is a Model T today?  Collectors of both come in the same basic
classes.  First, there are antiquarians who keep an old one in the
garage, polished and restored to new condition but hardly ever used.
Once a year, they warm it up and use it, just to prove that it still
works, but they don't make much practical use of it.

PDP-8 systems maintained by antiquarians are frequently in beautiful
shape.  Antiquarians worry about dust, chipped paint, and missing
switches, and they establish newsgroups and mailing lists to help them
locate parts and the advice needed to fix their machines.

In the second class are those who find old machines and soup them up,
replacing major parts to make a hotrod that only looks like the original
from the outside, or keeping the old mechanism and putting it to uses
that were never intended.  Some PDP-8 owners, for example, have built
PDP-8 systems with modern SCSI disk interfaces!  There is serious
interest in some quarters in constructing an omnibus board that would
support an IDE disk of the variety that was mass-produced for the
IBM PC/AT.

Last, there are the old folks who still use their old machines for their
intended purposes long after any sane economic analysis would recommend
such use.  If it ain't broke, don't fix it, and if it can be fixed,
why bother replacing it?  Both Model T Fords and the classic PDP-8
machines are simple enough that end users can maintain and repair them
indefinitely.  All you need to keep a vintage -8 running are a stock
of inexpensive silicon diodes and a stock of 2N3639B or better,
2N3640 transistors.

Unlike most modern personal computers, PDP-8 systems were routinely sold
with complete maintenance manuals; these included schematic diagrams,
explanations of not only how to use the devices, but how they are built,
and suggestions to those considering building their own peripherals.
Compared with many so-called "open systems" of today, the PDP-8 was far
better documented and far more open.

Preservation of the PDP-8 has proven to be of immense practical value
in defending against the rising tide of patents in the area of
interactive graphics.  For example, when Magnavox sued Nintendo
for half a billion dollars, a documented copy of a ping pong game,
written on a LINC back in the early 1960's, was crucial to the proof
that computer games predated the Magnavox patent by over 5 years.
The fact that this can be run today on a surviving LINC-8 makes
demonstrating this proof far easier than if the only surviving relic
was a dusty listing.

Finally, the PDP-8 is such a minimal machine that it is an excellent
introduction to how computers really work.  Over the years, many students
have built complete working PDP-8 systems from scratch as lab projects,
and the I/O environment on a PDP-8 is simple enough that it is a very
appropriate environment for learning operating system programming
techniques.

------------------------------

Subject: Who's Who?

C. Gordon Bell is generally credited with the original design of the
PDP-8.  He was also involved with recommending what became the PDP-11
when that design was competing with the design that probably became the
NOVA, and as vice president of research, he oversaw the development of
the DEC VAX family.

Alan Kotok worked with Bell in working up the original specifications
of the PDP-8.

Ben Gurley designed most of the big DEC machines, starting with the
PDP-1.  The actual design work on the -8, however, was done by Ed
deCastro, who later founded Data General to build the Nova.

Ken Olson ran DEC from the beginning.

Ed Yourdon, who later became well known as a programming methodology
guru, helped hack up the PAL III assembler for the -8 from PAL II.

Richard Merrill invented FOCAL and wrote the original (1968) and classic
FOCAL-69 interpreters for the PDP-8.  He also did early translations of
the interpreter to PDP-7/PDP-9 code and perhaps the earliest PDP-11
version.  In addition, he wrote the EDIT-8 paper-tape based text editor
based on the FOCAL built-in text editor.

Charles Lasner developed P?S/8, and he is widely known as a leader in
the movement to preserve these historic machines.  He created the
alt.sys.pdp8 newsgroup.

Wesley Clark developed the LINC while working at Lincoln Labs; this was
the first 12 bit minicomputer built with DEC parts.

Mary Allen Wilkes Clark developed the early LAP programs for the LINC.

Douglas W. Jones wrote this FAQ, but prior to the summer of 1992, he'd
never used a PDP-8.  He has also written a report on how to photocopy
and archivally bind ailing paperback books such as DEC's handouts, a
PAL-like cross assembler in C, and a UNIX-based PDP-8 emulator.

------------------------------

End of PDP-8 Frequently Asked Questions (posted every other month)
******************************************************************


From alderson@netcom.com Wed Aug 10 01:14:29 EDT 1994
Article: 987 of alt.sys.pdp8
Newsgroups: alt.sys.pdp8,alt.sys.pdp11,alt.folklore.computers
Path: bigblue.oit.unc.edu!concert!inxs.concert.net!taco.cc.ncsu.edu!lll-winken.llnl.gov!uop!pacbell.com!att-out!cbnewsj!cbnewsi!gw1!csn!csus.edu!netcom.com!alderson
From: alderson@netcom.com (Richard M. Alderson III)
Subject: Re: PDP-8 Frequently Asked Questions (posted every other month)
In-Reply-To: jones@cs.uiowa.edu's message of 8 Aug 94 08:08:08 GMT
Message-ID: <aldersonCu8rF6.6B7@netcom.com>
Followup-To: alt.folklore.computers
Reply-To: alderson@netcom.com
Fcc: /u52/alderson/postings
Organization: NETCOM On-line Communication Services (408 261-4700 guest)
References: <325b0i$2kd@nexus.uiowa.edu>
Date: Tue, 9 Aug 1994 00:16:18 GMT
Lines: 20
Xref: bigblue.oit.unc.edu alt.sys.pdp8:987 alt.folklore.computers:71624

In article <325b0i$2kd@nexus.uiowa.edu> jones@cs.uiowa.edu (Douglas W. Jones)
writes:

>Corrections and additions to this list are welcome!  The prices given are for
>minimal systems in the year the machine was first introduced.  The bits column
>indicates the word size.  Note that the DEC PDP-10 became the DECSYSTEM-20 as
>a result of marketing considerations, and DEC's VAX series of machines began
>as the Virtual Address eXtension of the never-produced PDP-11/78.

Welcome but ignored?

Once again, I have to point that the DECSYSTEM-20 differs from the DECsystem-10
in both hardware and software.

Maybe it's time for alt.sys.pdp10...
-- 
Rich Alderson   You know the sort of thing that you can find in any dictionary
                of a strange language, and which so excites the amateur philo-
                logists, itching to derive one tongue from another that they
                know better: a word that is nearly the same in form and meaning
                as the corresponding word in English, or Latin, or Hebrew, or
                what not.
                                                --J. R. R. Tolkien,
alderson@netcom.com                               _The Notion Club Papers_


From mol@trurl.df.lth.se Wed Aug 10 01:15:58 EDT 1994
Article: 988 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!gatech!howland.reston.ans.net!pipex!sunic!news.lth.se!mol
From: mol@trurl.df.lth.se (Magnus Olsson)
Newsgroups: alt.folklore.computers,alt.sys.pdp8,comp.arch,alt.config,comp.sys.dec
Subject: Proposal for PDP-10 group (was: PDP-8 Frequently Asked Questions (posted every other month))
Followup-To: alt.config,alt.folklore.computers,comp.sys.dec
Date: 9 Aug 1994 07:30:51 GMT
Organization: yacc - the Computer Society at Lund University and Lund Institute of Technology
Lines: 45
Message-ID: <327bbb$2vj@nic.lth.se>
References: <aldersonCu8rF6.6B7@netcom.com> <326pe2$lb8@nexus.uiowa.edu>
NNTP-Posting-Host: trurl.df.lth.se
Xref: bigblue.oit.unc.edu alt.folklore.computers:71638 alt.sys.pdp8:988 comp.arch:35440 alt.config:37441 comp.sys.dec:21718

In article <326pe2$lb8@nexus.uiowa.edu>,
Douglas W. Jones,201H MLH,3193350740,3193382879 <jones@pyrite.cs.uiowa.edu> wrote:
>From article <aldersonCu8rF6.6B7@netcom.com>,
>by alderson@netcom.com (Richard M. Alderson III):
>> Maybe it's time for alt.sys.pdp10...
>
>I would strongly encourage the creation of a FAQ for the PDP-10, either
>in a newsgroup devoted to that marvelous machine, or if you want, posted
>to alt.sys.pdp8.  

Yes! Please do!

>The PDP-10 was a very important machine in the history
>of academic computer science, and particularly in the history of
>artificial intelligence research.  An effort to provide an introduction
>to that architecture, an index of places where surviving software is
>archived, and pointers to efforts to construct emulators or other
>tools for preserving the machine's legacy would be very much worth
>while!  Do it!

Even though I have rather limited experience and knowledge of PDP-10's
I know enough to want to know more.

I second Doug's proposal wholeheartedly. Since the alt.sys.pdp8 and
alt.os.multics groups have been such successes, I hope a pdp10 group
might be equally successful.

Also, there's a new reason: There's one company that's actually
started making a new computer model which uses the PDP 10
architecture. I haven't heard much about them lately, but they seem to
be a sign of the survivability of the PDP 10 architecture. 

If you think alt.sys.pdp10 is a good idea I could help you creating it.
Or maybe we should go the whole hog and issue an RFD for comp.sys.pdp10?


NOTE: I'm crossposting this to a whole bunch of newsgroups. I've directed
followups to alt.folklore.computers, alt.config and comp.sys.dec only,
though, to keep down traffic in high-volume groups such as comp.arch.

              Magnus Olsson                | \e+      /_
 yacc - the Computer Society at LU and LTH |  \  Z   / q
              Lund, Sweden                 |   >----<           
 magnus@thep.lu.se,  mol@loglady.df.lth.se |  /      \===== g
PGP key available via finger or on request | /e-      \q


From rflukes@silver.cs.umanitoba.ca Wed Aug 10 01:16:22 EDT 1994
Article: 989 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!news.duke.edu!convex!cs.utexas.edu!utnut!utgpu!utcsri!newsflash.concordia.ca!canopus.cc.umanitoba.ca!silver.cs.umanitoba.ca!rflukes
From: rflukes@silver.cs.umanitoba.ca (Richard F. Lukes)
Newsgroups: alt.sys.pdp8
Subject: FREE: Diablo HyTYPE II Manual
Date: 9 Aug 1994 16:37:20 GMT
Organization: The University of Manitoba
Lines: 13
Distribution: na
Message-ID: <328bc0$4ug@canopus.cc.umanitoba.ca>
NNTP-Posting-Host: silver.cs.umanitoba.ca

I was cleaning out my basement and found a brand new maintenance
manual for the Xerox Diablo HyTYPE II daisy wheel printer.  This
is the model which was used as the printer with the WT-78 series
of PDP8 microprocessors.  Free to a good home,  if you pay for
shipping.

Thanks,
--Rich
-- 
Richard F. Lukes                    rflukes@silver.cs.UManitoba.CA
Computer Science Department         
University of Manitoba              HOME: (204)-257-6701
Winnipeg, Manitoba  CANADA          WORK: (204)-474-8696


From lasner@sunSITE.unc.edu Wed Aug 10 01:25:17 EDT 1994
Article: 990 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!sunSITE!lasner
From: lasner@sunSITE.unc.edu (Charles Lasner)
Newsgroups: alt.folklore.computers,alt.sys.pdp8,alt.sys.pdp11
Subject: Re: PDP-8 Frequently Asked Questions (posted every other month)
Date: 10 Aug 1994 05:25:55 GMT
Organization: University of North Carolina, Chapel Hill
Lines: 18
Message-ID: <329od3$1096@bigblue.oit.unc.edu>
References: <325b0i$2kd@nexus.uiowa.edu> <aldersonCu8rF6.6B7@netcom.com>
NNTP-Posting-Host: calzone.oit.unc.edu
Xref: bigblue.oit.unc.edu alt.folklore.computers:71746 alt.sys.pdp8:990

In article <aldersonCu8rF6.6B7@netcom.com>,
Richard M. Alderson III <alderson@netcom.com> wrote:
>In article <325b0i$2kd@nexus.uiowa.edu> jones@cs.uiowa.edu (Douglas W. Jones)
>writes:

>Once again, I have to point that the DECSYSTEM-20 differs from the DECsystem-10
>in both hardware and software.

And once again you have to be proven wrong.  TOPS-10 has been run on 
DECSYSTEM-20.  KL10 in red cabinets and blue cabinets changes the name but 
not the hardware.

If I choose to run P?S/8 on my PDP-8 instead of OS/8, do I have to change 
the name of the hardware?  And if I take it out of the H960 cabinet and 
place it on the table or in a non-DEC rack, do I have to change the name?

cjl (A PDP-8 by any other name ...)


From aad@lovecraft.amd.com Wed Aug 10 16:40:47 EDT 1994
Article: 991 of alt.sys.pdp8
Newsgroups: alt.sys.pdp8,alt.sys.pdp11,comp.sys.convex
Path: bigblue.oit.unc.edu!concert!inxs.concert.net!taco.cc.ncsu.edu!gatech!howland.reston.ans.net!usc!elroy.jpl.nasa.gov!decwrl!amd!amdint.amd.com!txnews.amd.com!lovecraft!aad
From: aad@lovecraft.amd.com (Anthony D'Atri)
Subject: Free VT62, DZ11, M9312, CIT-101, Unibus cables, Convex boards
Message-ID: <CuAzzE.573@txnews.amd.com>
Sender: news@txnews.amd.com
Nntp-Posting-Host: lovecraft
Organization: Advanced Micro Devices, Austin, TX, USA
Date: Wed, 10 Aug 1994 05:16:24 GMT
Lines: 8
Xref: bigblue.oit.unc.edu alt.sys.pdp8:991 comp.sys.convex:632

VT62 in working order
DZ11 & M9312 bootstrap terminator in unknown order
BC11 (I think) Unibus cables
CIT-101 needs video work
Various *scrapped* C1 & C2 boards


Free to anyone picking it up in Austin or paying shipping


From bqt@Krille.Update.UU.SE Wed Aug 10 16:43:01 EDT 1994
Article: 992 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!inxs.concert.net!taco.cc.ncsu.edu!lll-winken.llnl.gov!sundance.llnl.gov!osi-east2.es.net!cronkite.nersc.gov!dancer.ca.sandia.gov!overload.lbl.gov!agate!spool.mu.edu!howland.reston.ans.net!math.ohio-state.edu!jussieu.fr!univ-lyon1.fr!swidir.switch.ch!newsfeed.ACO.net!Austria.EU.net!EU.net!uunet!sunic!columba.udac.uu.se!Krille.Update.UU.SE!Krille.Update.UU.SE!not-for-mail
From: bqt@Krille.Update.UU.SE (Johnny Billquist)
Newsgroups: alt.folklore.computers,alt.sys.pdp8,alt.sys.pdp11
Subject: Re: PDP-8 Frequently Asked Questions (posted every other month)
Date: 10 Aug 1994 18:42:39 +0200
Organization: Update Computer Club
Lines: 31
Message-ID: <32b02d$6gm@Krille.Update.UU.SE>
References: <325b0i$2kd@nexus.uiowa.edu> <aldersonCu8rF6.6B7@netcom.com> <329od3$1096@bigblue.oit.unc.edu>
NNTP-Posting-Host: krille.update.uu.se
Xref: bigblue.oit.unc.edu alt.folklore.computers:71801 alt.sys.pdp8:992

In <329od3$1096@bigblue.oit.unc.edu> lasner@sunSITE.unc.edu (Charles Lasner) writes:

>In article <aldersonCu8rF6.6B7@netcom.com>,
>Richard M. Alderson III <alderson@netcom.com> wrote:
>>In article <325b0i$2kd@nexus.uiowa.edu> jones@cs.uiowa.edu (Douglas W. Jones)
>>writes:

>>Once again, I have to point that the DECSYSTEM-20 differs from the DECsystem-10
>>in both hardware and software.

>And once again you have to be proven wrong.  TOPS-10 has been run on 
>DECSYSTEM-20.  KL10 in red cabinets and blue cabinets changes the name but 
>not the hardware.

Hmmm, are you really sure about this, cjl?

The DECsystem-10 and DECSYSTEM-20 sure used the same CPU, but I am
pretty sure they have different pager boxes.
Maybe I should dig through the manuals, but they are stashed away
together with our DEC-2060 right now.

Also, there were hardware differences between the KL10A and KL10B.
You could only run TOPS-20 on the KL10B, but you could run TOPS-10
on the KL10A or KL10B (also if my memory is correct).

	Johnny
-- 
Johnny Billquist                  || "I'm on a bus
CS student at Uppsala University  ||  on a psychedelic trip
email: bqt@minsk.docs.uu.se       ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol


From jones@pyrite.cs.uiowa.edu Thu Aug 11 20:37:27 EDT 1994
Article: 993 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!rutgers!cis.ohio-state.edu!math.ohio-state.edu!jussieu.fr!univ-lyon1.fr!swidir.switch.ch!newsfeed.ACO.net!Austria.EU.net!EU.net!uunet!news.uiowa.edu!news
From: jones@pyrite.cs.uiowa.edu (Douglas W. Jones,201H MLH,3193350740,3193382879)
Newsgroups: alt.folklore.computers,alt.sys.pdp8,alt.sys.pdp11
Subject: Re: PDP-8 Frequently Asked Questions (posted every other month)
Date: 10 Aug 1994 20:42:05 GMT
Organization: University of Iowa, Iowa City, IA, USA
Lines: 16
Distribution: world
Message-ID: <32be2t$pci@nexus.uiowa.edu>
References: <32b02d$6gm@Krille.Update.UU.SE>
NNTP-Posting-Host: pyrite.cs.uiowa.edu
Xref: bigblue.oit.unc.edu alt.folklore.computers:71833 alt.sys.pdp8:993

From article <32b02d$6gm@Krille.Update.UU.SE>,
by bqt@Krille.Update.UU.SE (Johnny Billquist):
> 
> The DECsystem-10 and DECSYSTEM-20 sure used the same CPU, but I am
> pretty sure they have different pager boxes.
> Maybe I should dig through the manuals, but they are stashed away
> together with our DEC-2060 right now.

Ah, so the DECSYSTEM-10 and the DECSYSTEM-20 were about as different
as a PDP-8/E with the standard M837 KM8E memory extension control
and a PDP-8/E with a different memory manager, perhaps the one
designed to support one of the timesharing systems for the -8 that
required a nonstandard memory manager.

				Doug Jones
				jones@cs.uiowa.edu


From alderson@netcom.com Thu Aug 11 20:39:39 EDT 1994
Article: 994 of alt.sys.pdp8
Newsgroups: alt.folklore.computers,alt.sys.pdp8,alt.sys.pdp11
Path: bigblue.oit.unc.edu!concert!inxs.concert.net!taco.cc.ncsu.edu!lll-winken.llnl.gov!sundance.llnl.gov!osi-east2.es.net!cronkite.nersc.gov!dancer.ca.sandia.gov!overload.lbl.gov!agate!darkstar.UCSC.EDU!news.hal.COM!decwrl!netcomsv!netcom.com!alderson
From: alderson@netcom.com (Richard M. Alderson III)
Subject: Re: PDP-8 Frequently Asked Questions (posted every other month)
In-Reply-To: bqt@Krille.Update.UU.SE's message of 10 Aug 1994 18:42:39 +0200
Message-ID: <aldersonCuCCBI.C5H@netcom.com>
Reply-To: alderson@netcom.com
Fcc: /u52/alderson/postings
Organization: NETCOM On-line Communication Services (408 261-4700 guest)
References: <325b0i$2kd@nexus.uiowa.edu> <aldersonCu8rF6.6B7@netcom.com>
	<329od3$1096@bigblue.oit.unc.edu> <32b02d$6gm@Krille.Update.UU.SE>
Date: Wed, 10 Aug 1994 22:39:14 GMT
Lines: 55
Xref: bigblue.oit.unc.edu alt.folklore.computers:71847 alt.sys.pdp8:994

In article <32b02d$6gm@Krille.Update.UU.SE> bqt@Krille.Update.UU.SE
(Johnny Billquist) writes:

>In <329od3$1096@bigblue.oit.unc.edu> lasner@sunSITE.unc.edu (Charles Lasner)
>writes:

>>In article <aldersonCu8rF6.6B7@netcom.com>,
>>Richard M. Alderson III <alderson@netcom.com> wrote:

>>>Once again, I have to point that the DECSYSTEM-20 differs from the
>>>DECsystem-10 in both hardware and software.

>>And once again you have to be proven wrong.  TOPS-10 has been run on
>>DECSYSTEM-20.  KL10 in red cabinets and blue cabinets changes the name but
>>not the hardware.

Matter of definition.  The difference between the DEC-20 and the DEC-10 is
primarily, though not entirely, the software.  A KL10 running Tops-10 is a
DEC-10, not a DEC-20.  It wasn't until 1988 that they ran the same microcode.

The hardware does matter, though:  The -10 uses a different I/O and memory bus
than the -20 (although eventually Tops-10 was modified to allow it to run on
the -20 hardware, and vice versa).

>Hmmm, are you really sure about this, cjl?

Probably.

>The DECsystem-10 and DECSYSTEM-20 sure used the same CPU, but I am pretty sure
>they have different pager boxes.

Pagers, I/O, other differences.

>Maybe I should dig through the manuals, but they are stashed away together
>with our DEC-2060 right now.

Mine are right here on my desk.

>Also, there were hardware differences between the KL10A and KL10B.  You could
>only run TOPS-20 on the KL10B, but you could run TOPS-10 on the KL10A or KL10B
>(also if my memory is correct).

Nonsense.  The original box for Tops-20 is the KL10A without cache or extended
addressing (the 2040).  The 2050 adds the cache, and the 2060 adds extended
addressing (which we think late versions of the Tops-10 monitor used, though it
was not available to -10 user code).  The 2065 is a 2060 with a bigger, faster
cache and more main memory.

Both operating systems ran fine on all of them.  In addition, they both ran on
the KS10 (2020), which only had 512KW available.
-- 
Rich Alderson   You know the sort of thing that you can find in any dictionary
                of a strange language, and which so excites the amateur philo-
                logists, itching to derive one tongue from another that they
                know better: a word that is nearly the same in form and meaning
                as the corresponding word in English, or Latin, or Hebrew, or
                what not.
                                                --J. R. R. Tolkien,
alderson@netcom.com                               _The Notion Club Papers_


From weiner@world.std.com Thu Aug 11 20:40:35 EDT 1994
Article: 995 of alt.sys.pdp8
Newsgroups: alt.folklore.computers,alt.sys.pdp8,alt.sys.pdp11
Path: bigblue.oit.unc.edu!concert!inxs.concert.net!taco.cc.ncsu.edu!lll-winken.llnl.gov!sundance.llnl.gov!osi-east2.es.net!cronkite.nersc.gov!dancer.ca.sandia.gov!overload.lbl.gov!agate!spool.mu.edu!howland.reston.ans.net!math.ohio-state.edu!jussieu.fr!univ-lyon1.fr!swidir.switch.ch!newsfeed.ACO.net!Austria.EU.net!EU.net!uunet!world!weiner
From: weiner@world.std.com (Sam Weiner)
Subject: Re: PDP-8 Frequently Asked Questions (posted every other month)
Message-ID: <CuCGDo.40u@world.std.com>
Organization: The World Public Access UNIX, Brookline, MA
References: <325b0i$2kd@nexus.uiowa.edu> <aldersonCu8rF6.6B7@netcom.com> <329od3$1096@bigblue.oit.unc.edu> <32b02d$6gm@Krille.Update.UU.SE>
Date: Thu, 11 Aug 1994 00:08:12 GMT
Lines: 49
Xref: bigblue.oit.unc.edu alt.folklore.computers:71849 alt.sys.pdp8:995

In article <32b02d$6gm@Krille.Update.UU.SE>,
Johnny Billquist <bqt@Krille.Update.UU.SE> wrote:
>In <329od3$1096@bigblue.oit.unc.edu> lasner@sunSITE.unc.edu (Charles Lasner) writes:
>
>>In article <aldersonCu8rF6.6B7@netcom.com>,
>>Richard M. Alderson III <alderson@netcom.com> wrote:
>>>In article <325b0i$2kd@nexus.uiowa.edu> jones@cs.uiowa.edu (Douglas W. Jones)
>>>writes:
>
>>>Once again, I have to point that the DECSYSTEM-20 differs from the DECsystem-10
>>>in both hardware and software.
>
>>And once again you have to be proven wrong.  TOPS-10 has been run on 
>>DECSYSTEM-20.  KL10 in red cabinets and blue cabinets changes the name but 
               ORANGE    ^^^
>>not the hardware.

>
>Hmmm, are you really sure about this, cjl?
>
>The DECsystem-10 and DECSYSTEM-20 sure used the same CPU, but I am
>pretty sure they have different pager boxes.

	The KL pager was microcoded.  The proper code was loaded during
boot.

>Maybe I should dig through the manuals, but they are stashed away
>together with our DEC-2060 right now.

	While I no longer have access to a -10 or -20 (come on XKL, put a
system or two on the net already!) I do have most of a manual set handy.

>
>Also, there were hardware differences between the KL10A and KL10B.
>You could only run TOPS-20 on the KL10B, but you could run TOPS-10
>on the KL10A or KL10B (also if my memory is correct).

	Taking a quick look at the KL10A and KL10B TOPS-20 installation
manuals, it turns out that you can run TOPS-20 4.1 on a KL10A.  Anything
above that requires a KL10B.

	The last (still current?) setup in Salem NH had both KL1026 (TOPS-10)
and GIDNEY (TOPS-20) running on a 2065 depending which disks were used for
booting and set on-line.  Ah, for the days when the lab in Marlboro had 10
systems (and that was in 1986 when things started winding down.)

	Sam
	ex-Digital, ex-LCG
	(anyone need an old TOPS-x0 systems type?  I also do UNIX and DBMS.)


From bqt@Krille.Update.UU.SE Thu Aug 11 20:40:57 EDT 1994
Article: 996 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!rutgers!cis.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!EU.net!sunic!columba.udac.uu.se!Krille.Update.UU.SE!Krille.Update.UU.SE!not-for-mail
From: bqt@Krille.Update.UU.SE (Johnny Billquist)
Newsgroups: alt.folklore.computers,alt.sys.pdp8,alt.sys.pdp11
Subject: Re: PDP-8 Frequently Asked Questions (posted every other month)
Date: 11 Aug 1994 12:11:19 +0200
Organization: Update Computer Club
Lines: 26
Message-ID: <32ctgl$2tf@Krille.Update.UU.SE>
References: <32b02d$6gm@Krille.Update.UU.SE> <32be2t$pci@nexus.uiowa.edu>
NNTP-Posting-Host: krille.update.uu.se
Xref: bigblue.oit.unc.edu alt.folklore.computers:71888 alt.sys.pdp8:996

In <32be2t$pci@nexus.uiowa.edu> jones@pyrite.cs.uiowa.edu (Douglas W. Jones,201H MLH,3193350740,3193382879) writes:

>From article <32b02d$6gm@Krille.Update.UU.SE>,
>by bqt@Krille.Update.UU.SE (Johnny Billquist):
>> 
>> The DECsystem-10 and DECSYSTEM-20 sure used the same CPU, but I am
>> pretty sure they have different pager boxes.
>> Maybe I should dig through the manuals, but they are stashed away
>> together with our DEC-2060 right now.

>Ah, so the DECSYSTEM-10 and the DECSYSTEM-20 were about as different
>as a PDP-8/E with the standard M837 KM8E memory extension control
>and a PDP-8/E with a different memory manager, perhaps the one
>designed to support one of the timesharing systems for the -8 that
>required a nonstandard memory manager.

Exactly.

Anybody got ETOS-8? :-)

	Johnny
-- 
Johnny Billquist                  || "I'm on a bus
CS student at Uppsala University  ||  on a psychedelic trip
email: bqt@minsk.docs.uu.se       ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol


From bqt@Krille.Update.UU.SE Thu Aug 11 20:41:50 EDT 1994
Article: 997 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!rutgers!cis.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!EU.net!sunic!columba.udac.uu.se!Krille.Update.UU.SE!Krille.Update.UU.SE!not-for-mail
From: bqt@Krille.Update.UU.SE (Johnny Billquist)
Newsgroups: alt.folklore.computers,alt.sys.pdp8,alt.sys.pdp11
Subject: Re: PDP-8 Frequently Asked Questions (posted every other month)
Date: 11 Aug 1994 12:18:08 +0200
Organization: Update Computer Club
Lines: 69
Message-ID: <32ctte$362@Krille.Update.UU.SE>
References: <325b0i$2kd@nexus.uiowa.edu> <aldersonCu8rF6.6B7@netcom.com> 	<329od3$1096@bigblue.oit.unc.edu> <32b02d$6gm@Krille.Update.UU.SE> <aldersonCuCCBI.C5H@netcom.com>
NNTP-Posting-Host: krille.update.uu.se
Xref: bigblue.oit.unc.edu alt.folklore.computers:71889 alt.sys.pdp8:997

In <aldersonCuCCBI.C5H@netcom.com> alderson@netcom.com (Richard M. Alderson III) writes:

>In article <32b02d$6gm@Krille.Update.UU.SE> bqt@Krille.Update.UU.SE
>(Johnny Billquist) writes:

>>In <329od3$1096@bigblue.oit.unc.edu> lasner@sunSITE.unc.edu (Charles Lasner)
>>writes:

>>>In article <aldersonCu8rF6.6B7@netcom.com>,
>>>Richard M. Alderson III <alderson@netcom.com> wrote:

>>>>Once again, I have to point that the DECSYSTEM-20 differs from the
>>>>DECsystem-10 in both hardware and software.

>>>And once again you have to be proven wrong.  TOPS-10 has been run on
>>>DECSYSTEM-20.  KL10 in red cabinets and blue cabinets changes the name but
>>>not the hardware.

>Matter of definition.  The difference between the DEC-20 and the DEC-10 is
>primarily, though not entirely, the software.  A KL10 running Tops-10 is a
>DEC-10, not a DEC-20.  It wasn't until 1988 that they ran the same microcode.

Aha! This might explain my confusion.

>The hardware does matter, though:  The -10 uses a different I/O and memory bus
>than the -20 (although eventually Tops-10 was modified to allow it to run on
>the -20 hardware, and vice versa).

>>Hmmm, are you really sure about this, cjl?

>Probably.

>>The DECsystem-10 and DECSYSTEM-20 sure used the same CPU, but I am pretty sure
>>they have different pager boxes.

>Pagers, I/O, other differences.

>>Maybe I should dig through the manuals, but they are stashed away together
>>with our DEC-2060 right now.

>Mine are right here on my desk.

>>Also, there were hardware differences between the KL10A and KL10B.  You could
>>only run TOPS-20 on the KL10B, but you could run TOPS-10 on the KL10A or KL10B
>>(also if my memory is correct).

>Nonsense.  The original box for Tops-20 is the KL10A without cache or extended
>addressing (the 2040).  The 2050 adds the cache, and the 2060 adds extended
>addressing (which we think late versions of the Tops-10 monitor used, though it
>was not available to -10 user code).  The 2065 is a 2060 with a bigger, faster
>cache and more main memory.

>Both operating systems ran fine on all of them.  In addition, they both ran on
>the KS10 (2020), which only had 512KW available.

T20 stopped working on the KS10 as of V5.
The last version of T20 for the 2020 was 4.2, but it was 7.1(?) for
the KL10 machines.

Got you there... :-)
(I'm not entirely sure of the reason why, though. Memory constraints
or hardwarre... Beats me. Never played physical with a -2020).

	Johnny
-- 
Johnny Billquist                  || "I'm on a bus
CS student at Uppsala University  ||  on a psychedelic trip
email: bqt@minsk.docs.uu.se       ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol


From alderson@netcom.com Fri Aug 12 11:01:24 EDT 1994
Article: 998 of alt.sys.pdp8
Newsgroups: alt.folklore.computers,alt.sys.pdp8,alt.sys.pdp11
Path: bigblue.oit.unc.edu!concert!inxs.concert.net!taco.cc.ncsu.edu!lll-winken.llnl.gov!uop!pacbell.com!ihnp4.ucsd.edu!agate!spool.mu.edu!howland.reston.ans.net!math.ohio-state.edu!magnus.acs.ohio-state.edu!csn!csus.edu!netcom.com!alderson
From: alderson@netcom.com (Richard M. Alderson III)
Subject: Re: PDP-8 Frequently Asked Questions (posted every other month)
In-Reply-To: bqt@Krille.Update.UU.SE's message of 11 Aug 1994 12:18:08 +0200
Message-ID: <aldersonCuE0w4.5GJ@netcom.com>
Reply-To: alderson@netcom.com
Fcc: /u52/alderson/postings
Organization: NETCOM On-line Communication Services (408 261-4700 guest)
References: <325b0i$2kd@nexus.uiowa.edu> <aldersonCu8rF6.6B7@netcom.com>
	<329od3$1096@bigblue.oit.unc.edu> <32b02d$6gm@Krille.Update.UU.SE>
	<aldersonCuCCBI.C5H@netcom.com> <32ctte$362@Krille.Update.UU.SE>
Date: Thu, 11 Aug 1994 20:28:51 GMT
Lines: 38
Xref: bigblue.oit.unc.edu alt.folklore.computers:71964 alt.sys.pdp8:998

In article <32ctte$362@Krille.Update.UU.SE> bqt@Krille.Update.UU.SE
(Johnny Billquist) writes:

>In <aldersonCuCCBI.C5H@netcom.com> alderson@netcom.com
>(Richard M. Alderson III) writes:

>>Both operating systems ran fine on all of them.  In addition, they both ran
>>on the KS10 (2020), which only had 512KW available.

>T20 stopped working on the KS10 as of V5.
>The last version of T20 for the 2020 was 4.2, but it was 7.1(?) for
>the KL10 machines.

7.0; I was one of the field test sites, and chaired the DECUS session at which
it was announced to a room set up for 400 people.  Never mind that there were
maybe 20 there.  ;->

>Got you there... :-)
>(I'm not entirely sure of the reason why, though. Memory constraints
>or hardwarre... Beats me. Never played physical with a -2020).

Little of both:  Version 5 ran in extended memory only, which was unavailable
on the 2020.  However, it remained a *supported* processor and version until
the end.

Note that I wasn't necessarily talking about the latest version of each
operating system:  Tops-10 7.04 uses Tops-20 paging, and may not run on anyting
but a KL10B.  (I've never been a -10 person, so I'm not fully up on their
limitations or advantages.)

Oh, that reminds me:  Another major difference between Tops-10 and Tops-20 is
that the former can handle symmetric multiprocessor configurations; the latter
is strictly uniprocessor.
-- 
Rich Alderson   You know the sort of thing that you can find in any dictionary
                of a strange language, and which so excites the amateur philo-
                logists, itching to derive one tongue from another that they
                know better: a word that is nearly the same in form and meaning
                as the corresponding word in English, or Latin, or Hebrew, or
                what not.
                                                --J. R. R. Tolkien,
alderson@netcom.com                               _The Notion Club Papers_


From mol@loglady.df.lth.se Fri Aug 12 11:02:38 EDT 1994
Article: 999 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!inxs.concert.net!taco.cc.ncsu.edu!lll-winken.llnl.gov!ames!agate!howland.reston.ans.net!pipex!sunic!news.lth.se!loglady.df.lth.se!mol
From: mol@loglady.df.lth.se (Magnus Olsson)
Newsgroups: alt.config,alt.folklore.computers,comp.sys.dec,alt.sys.pdp8,alt.sys.pdp11,vmsnet.pdp11,news.groups
Subject: Proposal: alt.sys.pdp10
Followup-To: alt.config
Date: 12 Aug 1994 08:51:33 GMT
Organization: yacc - the Computer Society at Lund University and Lund Institute of Technology
Lines: 35
Message-ID: <32fd6l$srj@nic.lth.se>
NNTP-Posting-Host: loglady.df.lth.se
Xref: bigblue.oit.unc.edu alt.config:37894 alt.folklore.computers:72009 comp.sys.dec:21830 alt.sys.pdp8:999 news.groups:88390

(Please note the Followup-To line)


I propose the creation of the group alt.sys.pdp10.

The purpose of the group would be the discussion of all aspects of
PDP-10 and DEC-20 computers and clones, their architecture, assembly
language, and their various operating systems (TOPS-10, Tenex, TOPS-20,
ITS). Also, it could be a place to discuss the culture and folklore of
these systems, and for old PDP gurus to propagate their wisdom.

I'm well aware that there aren't many of these systems left running
nowadays, but I know that there are lots of people on the net with
experience from them. Also, lots of younger people who've grown up
with VAXen have heard about these fabulous machines and are intersted
in learning more. Hopefully, this can generate quite a lot of traffic
(if you don't believe me, check out alt.os.multics, which has been a
success despite dealing with a dying system).

It should also be mentioned that there are already the groups
alt.sys.pdp8 and alt.sys.pdp11.

The group has been proposed and discussed during the week on
alt.sys.pdp8, alt.folklore.computers and parts of the discussion has
been crossposted to alt.config. 

This is a more formal announcement, according to the altnet guidelines, 
that if there are no substantial objections I will send out a newgroup
message for alt.sys.pdp10 in a week (i.e. Friday August 19).

              Magnus Olsson                | \e+      /_
 yacc - the Computer Society at LU and LTH |  \  Z   / q
              Lund, Sweden                 |   >----<           
 magnus@thep.lu.se,  mol@loglady.df.lth.se |  /      \===== g
PGP key available via finger or on request | /e-      \q


From geremin@decus.org.au Sat Aug 13 14:42:24 EDT 1994
Article: 1000 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!rutgers!usc!howland.reston.ans.net!agate!msuinfo!harbinger.cc.monash.edu.au!news.cs.su.oz.au!metro!decus!geremin
From: geremin@decus.org.au
Newsgroups: decus.nop,vmsnet.pdp-11,alt.sys.pdp8,alt.sys.pdp11
Subject: NOP SIG meeting for August in OZ.
Message-ID: <1994Aug13.224007.14973@decus.org.au>
Date: 13 Aug 94 22:40:07 AEST
Organization: DECUS Australia
Lines: 36
Xref: bigblue.oit.unc.edu vmsnet.pdp-11:1436 alt.sys.pdp8:1000


   	DECUS  Australia  *  NOP  SIG   -   August, 94  Meetings,   
	----------------     ========       ==========  --------


AGM     When :  15:00 - Murray Room, Thursday, 25th August, 1994.
---
        Where:  Canberra - National Convention Centre.

        Why  :  To present the Chairman's Annual Report.
		To Elect a Committee for 94-95 operations.
		Presentation of awards.
		Report on Inaugral Meeting of Aust. Comp. Museum Society.
		Other business from members.

	Who  :	At least ten official NOP SIG members.



Monthly When :  18:00 (approx), on Wednesday, 31st August, 1994.
-------
        Where:  Dale Woodside's, 442 Pennant Hills Road, Beecroft.
		Note - parking in back street. (Boots at back door).

	Why  :	DECUS-94 Symposium report.
		1994 Board Elections.
		NOP SIG brochure/public image - Tom Gayford.
		NOP SIG Mission Statement - (bring suggestions).
		Relations with Aust. Comp. Museum Society.
		September meeting location.

        RSVP :  Dale on 02-484 0160.

			JAG  for   Mike Chevallier, NOP SIG chairman.

-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-


From mol@trurl.df.lth.se Tue Aug 16 14:06:22 EDT 1994
Article: 1001 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!news-feed-1.peachnet.edu!emory!swrinde!pipex!sunic!news.lth.se!mol
From: mol@trurl.df.lth.se (Magnus Olsson)
Newsgroups: alt.folklore.computers,comp.sys.dec,vmsnet.pdp-11,alt.sys.pdp11,alt.sys.pdp8
Subject: Re: Group for old computers (was: RFD: alt.sys.obsolete (Was: Re: Proposal for PDP-10 group))
Date: 16 Aug 1994 11:24:57 GMT
Organization: yacc - the Computer Society at Lund University and Lund Institute of Technology
Lines: 72
Message-ID: <32q7m9$612@nic.lth.se>
References: <werme.776546437@alingo.zk3.dec.com> <11AUG199408483833@almach.caltech.edu> <32f64v$kds@nic.lth.se> <13AUG199410052681@almach.caltech.edu>
NNTP-Posting-Host: trurl.df.lth.se
Xref: bigblue.oit.unc.edu alt.folklore.computers:72364 comp.sys.dec:21925 vmsnet.pdp-11:1453 alt.sys.pdp8:1001

In article <13AUG199410052681@almach.caltech.edu>,
Timothy D. Shoppa x4256 <shoppa@almach.caltech.edu> wrote:
>In article <32f64v$kds@nic.lth.se>, mol@trurl.df.lth.se (Magnus Olsson) writes...

[about vmsnet.pdp11]

>Yes, there exists a good amount of opposition to the vmsnet hierarchy
>at many sites.  

IMHO the vmsnet hierarchy may have made sense when it was created (since
Usnete used to be much more Unix-dominated than it is today) but I have 
some difficulty understanding the need for a top-level hierarchy for
a specific operating system.(I'm of course referring to the hierarchy as
such, *not* to the discussions going on which I'm sure make very much
sense indeed). Let's at least be grateful there's not a special
msdos-net hierarchy... :-)

>Still, it is more widely distributed than alt.sys.pdp11,
>and carries substantially more traffic.
[...]

>I am all for the creation of newsgroups that will broaden the
>access of readres to older-hardware-related issues.  However, alt.*
>newsgroups that are viewed as duplicates of already well-established
>groups often have substantially poorer distribution than
>the established groups; this is reflected in the stats above.

I agree with you, and can only lament the fact that vmsnet isn't considered
"interesting", "politically correct" or whatever by many sysadmins :-(.

>I strongly the believe the best route to take would be creation
>of a comp.sys.dec.pdp (or similarly-named) newsgroup, which would
>cover all older DEC hardware.

I don't really think so. A PDP-8 doesn't have very much in common with
a DEC-20. IMHO it's important for psychological reasons to 
have separate groups for machines that are so different - if nothing else,
otherwise ther might be a feeling that a hypothetical comp.sys.pdp would
be "taken over" by, say, PDP-11 discussion, and that PDP-10 discussion
wouldn't be appropriate (even though it would be expressly within charter).

Witness the situation on alt.sys.pdp8: It has repeatedly been stated
that discussion of _all_ PDP systems is welcome there, yet the
discussion is exclusively about 8's. Newcomers see that, and of course
they refrain from asking about 10's. 


I do think that there's sufficient traffic and interest both for
comp.sys.pdp11 and comp.sys.pdp8. If anybody wants to go through the
hassle of going through the RFD/CFV/vote proecdure for them I'd be
happy, but I'm not going to do it myself (not right now, anyway). As
for comp.sys.pdp10, well, I don't know. Let's try alt.sys.pdp10 first,
shall we, and se how much interest it generates. 

>>2) A feeling that vmsnet isn't the right place for a pdp11 group
>>   (after all, you can't run VMS on a PDP-11).
>
>Not exactly true.  Early versions of VMS were tested on a 11/70 emulating
>the VAX instruction set.  A friend of mine who was a DEC field service
>engineer at the time is promising to deliver more details of this setup.

I heard it the other way round: that VMS 1.0 was written in PDP-11 code,
and that it ran using the VAX 11's compatibility mode. Only for version 2.0
did they move up to native 32-bit code. (Of course, it was only the OS
itself that ran in compatibility mode; you could still se 32-bit code
for applications).

              Magnus Olsson                | \e+      /_
 yacc - the Computer Society at LU and LTH |  \  Z   / q
              Lund, Sweden                 |   >----<           
  mol@df.lth.se / magnus.olsson@ivab.se    |  /      \===== g
PGP key available via finger or on request | /e-      \q


From moisan@bronze.lcs.mit.edu Tue Aug 16 14:07:17 EDT 1994
Article: 1002 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!inxs.concert.net!taco.cc.ncsu.edu!gatech!europa.eng.gtefsd.com!MathWorks.Com!news2.near.net!bloom-beacon.mit.edu!ai-lab!bronze.lcs.mit.edu!not-for-mail
From: moisan@bronze.lcs.mit.edu (David Moisan)
Newsgroups: comp.sys.dec,comp.sys.dec.micro,alt.folklore.computers,alt.sys.pdp8
Subject: RX50 problems--did they use special disks?
Followup-To: poster
Date: 16 Aug 1994 12:51:41 -0400
Organization: MIT LCS guest machine
Lines: 23
Message-ID: <32qqqt$nd8@bronze.lcs.mit.edu>
NNTP-Posting-Host: bronze.ai.mit.edu
Summary: How can I use regular IBM DSDD 5-1/4" media on DecMATE RX50?
Xref: bigblue.oit.unc.edu comp.sys.dec:21940 comp.sys.dec.micro:3073 alt.folklore.computers:72408 alt.sys.pdp8:1002

I've a DECmate II I'm trying to get working, and I've run into a problem.  
I'm trying to copy a WPS-8 system disk, but it bombs everytime it activates
drive 1.  I'm using IBM-style 5-1/4" DSDD media, with hub rings, in that drive.
System Test Disk indicates a Drive 1 problem.

The DECmate is a standard config, single RX50, CP/M board (but no 
CP/M OS :''( ).  I ran DEC's two-disk "Intro to MATH" tutorial, and 
it reported no problems when it ran the second drive.

I once used a Rainbow, with, I believe, the same drive, and it required
96 TPI RX50 formatted disks.  Can this be my problem?  Is there a workaround?
I'm stuck here and I'd really like to get this puppy going again.
 
Thanks muchly in advance,

Dave


-- 
| David Moisan, N1KGH    /^\_/^\   moisan@bronze.lcs.mit.edu      |
| 86 Essex St. Apt #204 ( o ^ o )  n1kgh@amsat.org                |
| Salem. MA 01970-5225     | |     ce393@cleveland.freenet.edu    |
|                                                                 |


From cchd@lucifer.latrobe.edu.au Thu Aug 18 06:10:37 EDT 1994
Article: 1003 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!gatech!newsxfer.itd.umich.edu!europa.eng.gtefsd.com!library.ucla.edu!ihnp4.ucsd.edu!munnari.oz.au!ariel.ucs.unimelb.EDU.AU!ucsvc.ucs.unimelb.edu.au!lugb!lucifer.latrobe.edu.au!cchd
Newsgroups: alt.folklore.computers,comp.sys.dec,vmsnet.pdp-11,alt.sys.pdp11,alt.sys.pdp8
Subject: Re: Group for old computers (was: RFD: alt.sys.obsolete (Was: Re: Proposal for PDP-10 group))
Message-ID: <1994Aug17.025814.7642@lugb.latrobe.edu.au>
From: cchd@lucifer.latrobe.edu.au (Huw Davies)
Date: Wed, 17 Aug 1994 02:58:14 GMT
Sender: news@lugb.latrobe.edu.au (USENET News System)
References: <32f64v$kds@nic.lth.se> <13AUG199410052681@almach.caltech.edu> <32q7m9$612@nic.lth.se>
Organization: La Trobe University
Lines: 30
Xref: bigblue.oit.unc.edu alt.folklore.computers:72473 comp.sys.dec:21962 vmsnet.pdp-11:1461 alt.sys.pdp8:1003

In article <32q7m9$612@nic.lth.se> mol@trurl.df.lth.se (Magnus Olsson) writes:
>
>>>2) A feeling that vmsnet isn't the right place for a pdp11 group
>>>   (after all, you can't run VMS on a PDP-11).
>>
>>Not exactly true.  Early versions of VMS were tested on a 11/70 emulating
>>the VAX instruction set.  A friend of mine who was a DEC field service
>>engineer at the time is promising to deliver more details of this setup.
>
>I heard it the other way round: that VMS 1.0 was written in PDP-11 code,
>and that it ran using the VAX 11's compatibility mode. Only for version 2.0
>did they move up to native 32-bit code. (Of course, it was only the OS
>itself that ran in compatibility mode; you could still se 32-bit code
>for applications).

My understanding was that some/most? of the development of VAX/VMS was done
on pair of 11/70s with the second 11/70 doing most of the VAX code
emultation.

V1 of VMS was native - most applications software was emulated however.

I'm off to DECUS Australia and I'll find out some more about the original
VMS development - one of the original VAX architects will be there - perhaps
he'll answer a few questions.....

-- 
  Huw Davies           | Huw.Davies@latrobe.edu.au
  Computing Services   | Phone: +61 3 479 1500   Fax: +61 3 479 1999
  La Trobe University  | I own an Alfa to keep me poor in a monetary
  Melbourne Australia  | sense, but rich in so many other ways


From lhauser@rs6a.wln.com Thu Aug 18 06:12:01 EDT 1994
Article: 1004 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!news-feed-1.peachnet.edu!news.duke.edu!eff!news.kei.com!rs6a.wln.com!rs6a.wln.com!lhauser
From: lhauser@rs6a.wln.com (Williams Kastner Gibbs)
Newsgroups: alt.sys.pdp8
Subject: PDP-8 Emulator?
Date: 17 Aug 1994 04:27:08 GMT
Organization: WLN
Lines: 8
Message-ID: <32s3is$lkj@rs6a.wln.com>
NNTP-Posting-Host: rs6a.wln.com
X-Newsreader: TIN [version 1.1 PL8]


Is there a PDP-8 emulator available already compiled for IBM-PC (286 or
higher)? I have the C sources but no C compiler. Any help would be
appreciated.

Lee Hauser
lhauser@wln.com


From weiner@world.std.com Thu Aug 18 06:13:28 EDT 1994
Article: 1005 of alt.sys.pdp8
Newsgroups: alt.folklore.computers,alt.sys.pdp8,alt.sys.pdp11
Path: bigblue.oit.unc.edu!concert!news.duke.edu!MathWorks.Com!uhog.mit.edu!news.mtholyoke.edu!world!weiner
From: weiner@world.std.com (Sam Weiner)
Subject: Re: PDP-8 Frequently Asked Questions (posted every other month)
Message-ID: <Cunw5v.9rE@world.std.com>
Organization: The World Public Access UNIX, Brookline, MA
References: <325b0i$2kd@nexus.uiowa.edu> <aldersonCuCCBI.C5H@netcom.com> <32ctte$362@Krille.Update.UU.SE> <aldersonCuE0w4.5GJ@netcom.com>
Date: Wed, 17 Aug 1994 04:22:41 GMT
Lines: 58
Xref: bigblue.oit.unc.edu alt.folklore.computers:72474 alt.sys.pdp8:1005

In article <aldersonCuE0w4.5GJ@netcom.com>,
Richard M. Alderson III <alderson@netcom.com> wrote:
>In article <32ctte$362@Krille.Update.UU.SE> bqt@Krille.Update.UU.SE
>(Johnny Billquist) writes:
>
>>In <aldersonCuCCBI.C5H@netcom.com> alderson@netcom.com
>>(Richard M. Alderson III) writes:
>
>>>Both operating systems ran fine on all of them.  In addition, they both ran
>>>on the KS10 (2020), which only had 512KW available.
>
>>T20 stopped working on the KS10 as of V5.
>>The last version of T20 for the 2020 was 4.2, but it was 7.1(?) for
>>the KL10 machines.
>
>7.0; I was one of the field test sites, and chaired the DECUS session at which
>it was announced to a room set up for 400 people.  Never mind that there were
>maybe 20 there.  ;->

Actually, the last KS/KL10A TOPS-20 version released by DEC was 4.1.  I
believe 4.2 was a Panda special (Mark?)

>
>>Got you there... :-)
>>(I'm not entirely sure of the reason why, though. Memory constraints
>>or hardwarre... Beats me. Never played physical with a -2020).
>
>Little of both:  Version 5 ran in extended memory only, which was unavailable
>on the 2020.  However, it remained a *supported* processor and version until
>the end.
>
>Note that I wasn't necessarily talking about the latest version of each
>operating system:  Tops-10 7.04 uses Tops-20 paging, and may not run on anyting
>but a KL10B.  (I've never been a -10 person, so I'm not fully up on their
>limitations or advantages.)

TOPS-10 7.04 does indeed run on a KS10 though it may lack some features
(while I cut my teeth on TOPS-10 back in KA days, my time at DEC was spent
 in the TOPS-20 group so I'm not as up on things -10 either.)  The wonders
of MONGEN handled whatever differences there were.  Rich, you should be
able to look through the sources soon, right?

>
>Oh, that reminds me:  Another major difference between Tops-10 and Tops-20 is
>that the former can handle symmetric multiprocessor configurations; the latter
>is strictly uniprocessor.

TOPS-20 had clusters (aka Common File System or CFS) as of 6.1 (or 6.0?)
which provided file sharing, including locking.  Version 7.0 added a shared
PS: (for login info), and cluster-wide ENQ (only 1022 used this as far as I
know,) Galaxy, and INFO.  TOPS-20 could have been made SMP fairly easily
according to a document I found but most DECSYSTEM-20s weren't configured
for the external memory required so it was more of a marketing than
technical decision (the Jupiter design may have also been a factor.)
Stanford supposedly had a TENEX-SMP system running.

	Sam
	ex-LCG, ex-Digital


From omega@infi.net Thu Aug 18 06:13:41 EDT 1994
Article: 1006 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!news-feed-1.peachnet.edu!news.duke.edu!MathWorks.Com!europa.eng.gtefsd.com!sundog.tiac.net!news.sprintlink.net!news.infi.net!larry.infi.net!omega
From: omega@infi.net (Kenneth Martin)
Newsgroups: alt.sys.pdp8
Subject: Re: PDP-8 Emulator?
Date: 17 Aug 1994 09:17:34 GMT
Organization: InfiNet
Lines: 6
Message-ID: <32skje$b3q@lucy.infi.net>
References: <32s3is$lkj@rs6a.wln.com>
NNTP-Posting-Host: larry.infi.net
X-Newsreader: TIN [version 1.2 PL2]

Post the sources here, or E-Mail them to me, and I can compile/port it to
DOS. 

--
The Omega Concern (Kenneth Martin), IZCC #136
omega@infi.net                


From McCrohan@iol.ie Thu Aug 18 06:13:54 EDT 1994
Article: 1007 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!gatech!howland.reston.ans.net!EU.net!ieunet!iol!iol!not-for-mail
From: McCrohan@iol.ie (Mike McCrohan)
Newsgroups: alt.folklore.computers,comp.sys.dec,vmsnet.pdp-11,alt.sys.pdp11,alt.sys.pdp8
Subject: Re: Group for old computers
Date: 18 Aug 1994 10:14:52 +0100
Organization: Ireland On-Line
Lines: 30
Sender: mccrohan@iol.ie
Message-ID: <7hDKkGakfSRE069yn@iol.ie>
References: <werme.776546437@alingo.zk3.dec.com> <11AUG199408483833@almach.caltech.edu> <32f64v$kds@nic.lth.se> <13AUG199410052681@almach.caltech.edu> <32q7m9$612@nic.lth.se>
NNTP-Posting-Host: ulysses.iol.ie
Xref: bigblue.oit.unc.edu alt.folklore.computers:72597 comp.sys.dec:21991 vmsnet.pdp-11:1470 alt.sys.pdp8:1007

In article <32q7m9$612@nic.lth.se>, mol@trurl.df.lth.se (Magnus Olsson) wrote:
> In article <13AUG199410052681@almach.caltech.edu>,
> Timothy D. Shoppa x4256 <shoppa@almach.caltech.edu> wrote:
> >In article <32f64v$kds@nic.lth.se>, mol@trurl.df.lth.se (Magnus Olsson) writes...

> >Not exactly true.  Early versions of VMS were tested on a 11/70 emulating
> >the VAX instruction set.  A friend of mine who was a DEC field service
> >engineer at the time is promising to deliver more details of this setup.
> 
> I heard it the other way round: that VMS 1.0 was written in PDP-11 code,
> and that it ran using the VAX 11's compatibility mode. Only for version 2.0
> did they move up to native 32-bit code. (Of course, it was only the OS
> itself that ran in compatibility mode; you could still se 32-bit code
> for applications).

I think that the truth is somewhere between the two comments. VMS was
designed/written by the same man (Dave Cutler) that wrote much of
RSX-11/mumble. Many of the RSX utilities were used on VMS V1.n
initially, running in compatability mode, but over time got re-written
in native mode. It was about VMS V3.0 that all of VMS ran in native
mode, finally. [Thoughts of deja vu wrt Alpha. Vax ported from the
11-base via HW compatability; Alpha is porting from VAX but with SW
emulators. The speed of the successful migration of OS, tools, etc to
alpha is all the more impressive when you look back at how long it took
for VMS to go completely native and not be merely an RSX extension.]

Dave C is, of course, the man heading up the Windows-NT effort. Ever
wonder how come NT sounds so much like a VMS rewrite?


From jleslie@dmccorp.com Thu Aug 18 06:14:12 EDT 1994
Article: 1008 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!gatech!howland.reston.ans.net!swrinde!news.uh.edu!uuneo.neosoft.com!igate.dmccorp.com!jleslie
From: jleslie@dmccorp.com (Jerry Leslie)
Newsgroups: alt.folklore.computers,comp.sys.dec,vmsnet.pdp-11,alt.sys.pdp11,alt.sys.pdp8
Subject: Re: Group for old computers
Followup-To: alt.folklore.computers,comp.sys.dec,vmsnet.pdp-11,alt.sys.pdp11,alt.sys.pdp8
Date: 18 Aug 1994 09:51:47 GMT
Organization: NeoSoft Internet Services   +1 713 684 5969
Lines: 25
Message-ID: <32vavj$n12@uuneo.neosoft.com>
References: <werme.776546437@alingo.zk3.dec.com> <11AUG199408483833@almach.caltech.edu> <32f64v$kds@nic.lth.se> <13AUG199410052681@almach.caltech.edu> <32q7m9$612@nic.lth.se> <7hDKkGakfSRE069yn@iol.ie>
NNTP-Posting-Host: igate.dmccorp.com
X-Newsreader: TIN [version 1.2 PL2]
Xref: bigblue.oit.unc.edu alt.folklore.computers:72599 comp.sys.dec:21993 vmsnet.pdp-11:1473 alt.sys.pdp8:1008

Mike McCrohan (McCrohan@iol.ie) wrote:
: In article <32q7m9$612@nic.lth.se>, mol@trurl.df.lth.se (Magnus Olsson) wrote:
: > In article <13AUG199410052681@almach.caltech.edu>,
: > Timothy D. Shoppa x4256 <shoppa@almach.caltech.edu> wrote:
: > >In article <32f64v$kds@nic.lth.se>, mol@trurl.df.lth.se (Magnus Olsson) writes...


: Dave C is, of course, the man heading up the Windows-NT effort. Ever
: wonder how come NT sounds so much like a VMS rewrite?


And why the rumor that the name "Windows-NT" was a justification for the
acronym "WNT", which is "VMS" transposed up by one letter ?  This was done 
for the computer in the the movie "2001, a Space Odessy", HAL, which
is "IBM" transposed down by one letter.


--Gerald (Jerry) R. Leslie
  Staff Engineer
  Dynamic Matrix Control Corporation    (my opinions are my own)
  P.O. Box 721648                       9896 Bissonnet
  Houston, Texas 77272                  Houston, Texas, 77036
  713/272-5065                          713/272-5200 (fax)
  gleslie@isvsrv.enet.dec.com
  jleslie@dmccorp.com


From mje@pookie.pass.wayne.edu Thu Aug 18 18:02:44 EDT 1994
Article: 1009 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!gatech!howland.reston.ans.net!europa.eng.gtefsd.com!newsxfer.itd.umich.edu!news1.oakland.edu!news
From: mje@pookie.pass.wayne.edu (Michael J. Edelman)
Newsgroups: alt.folklore.computers,comp.sys.dec,vmsnet.pdp-11,alt.sys.pdp11,alt.sys.pdp8
Subject: Re: Group for old computers
Date: 18 Aug 1994 12:04:48 GMT
Organization: Wayne State University
Lines: 12
Message-ID: <32vip0$ek9@oak.oakland.edu>
References: <32vavj$n12@uuneo.neosoft.com>
Reply-To: mje@pookie.pass.wayne.edu
NNTP-Posting-Host: pookie.pass.wayne.edu
Xref: bigblue.oit.unc.edu alt.folklore.computers:72617 comp.sys.dec:21996 vmsnet.pdp-11:1475 alt.sys.pdp8:1009

In article n12@uuneo.neosoft.com,  jleslie@dmccorp.com (Jerry Leslie) writes:
..
>And why the rumor that the name "Windows-NT" was a justification for the
>acronym "WNT", which is "VMS" transposed up by one letter ?  This was done 
>for the computer in the the movie "2001, a Space Odessy", HAL, which
>is "IBM" transposed down by one letter.
 
Both Kubrick and Clark claim this was just a lucky coincidence, and that the name
HAL was chosen indepedantly of such considerations.

--mike


From lhauser@rs6a.wln.com Sat Aug 20 04:59:29 EDT 1994
Article: 1010 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!inxs.concert.net!taco.cc.ncsu.edu!lll-winken.llnl.gov!overload.lbl.gov!agate!library.ucla.edu!europa.eng.gtefsd.com!MathWorks.Com!news.kei.com!rs6a.wln.com!rs6a.wln.com!lhauser
From: lhauser@rs6a.wln.com (Williams Kastner Gibbs)
Newsgroups: alt.folklore.computers,comp.sys.dec,vmsnet.pdp-11,alt.sys.pdp11,alt.sys.pdp8
Subject: Re: Group for old computers
Date: 19 Aug 1994 04:48:31 GMT
Organization: WLN
Lines: 17
Message-ID: <331div$k36@rs6a.wln.com>
References: <32vavj$n12@uuneo.neosoft.com>
NNTP-Posting-Host: rs6a.wln.com
X-Newsreader: TIN [version 1.1 PL8]
Xref: bigblue.oit.unc.edu alt.folklore.computers:72690 comp.sys.dec:22022 vmsnet.pdp-11:1482 alt.sys.pdp8:1010

Jerry Leslie (jleslie@dmccorp.com) wrote:

: And why the rumor that the name "Windows-NT" was a justification for the
: acronym "WNT", which is "VMS" transposed up by one letter ?  This was done 
: for the computer in the the movie "2001, a Space Odessy", HAL, which
: is "IBM" transposed down by one letter.

Arthur C. Clarke has debunked the IBM/HAL myth. He claims that if he'd
though of that angle, he would have changed the name, wanting nothing to
do with IBM. HAL stands for Heuristically programmed ALgorithmic computer.

That doesn't mean, of course, that someone at Mickeysoft doesn't believe
that's true, and did indeed try the rot-1 transpostion of VMS...


Lee


From peter@nmti.com Sat Aug 20 05:00:02 EDT 1994
Article: 1011 of alt.sys.pdp8
Newsgroups: alt.folklore.computers,comp.sys.dec,vmsnet.pdp-11,alt.sys.pdp11,alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!rutgers!usc!elroy.jpl.nasa.gov!swrinde!news.uh.edu!uuneo.neosoft.com!nmtigw!peter
From: peter@nmti.com (Peter da Silva)
Subject: Re: Group for old computers
Message-ID: <id.SM8C1.B32@nmti.com>
Sender: peter@nmti.com (peter da silva)
Organization: Network/development platform support, NMTI
References: <32vavj$n12@uuneo.neosoft.com> <331div$k36@rs6a.wln.com>
Date: Fri, 19 Aug 1994 12:44:50 GMT
Lines: 12
Xref: bigblue.oit.unc.edu alt.folklore.computers:72749 comp.sys.dec:22033 vmsnet.pdp-11:1484 alt.sys.pdp8:1011

In article <331div$k36@rs6a.wln.com>,
Williams Kastner Gibbs <lhauser@rs6a.wln.com> wrote:
> That doesn't mean, of course, that someone at Mickeysoft doesn't believe
> that's true, and did indeed try the rot-1 transpostion of VMS...

Dave Cutler's response to a question about the VMS/WNT naming connection was
along the lines of "it took you THIS long to notice?"...
-- 
Peter da Silva                                            `-_-'
Network Management Technology Incorporated                 'U`
1601 Industrial Blvd.     Sugar Land, TX  77478  USA
+1 713 274 5180                       "Hast Du heute schon Deinen Wolf umarmt?"


From shendrix@escape.widomaker.com Sat Aug 20 05:00:16 EDT 1994
Article: 1012 of alt.sys.pdp8
Newsgroups: alt.folklore.computers,comp.sys.dec,vmsnet.pdp-11,alt.sys.pdp11,alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!gatech!howland.reston.ans.net!math.ohio-state.edu!jussieu.fr!univ-lyon1.fr!swidir.switch.ch!newsfeed.ACO.net!news.sztaki.hu!EU.net!uunet!news.widomaker.com!escape!shendrix
From: shendrix@escape.widomaker.com (Shannon Hendrix)
Subject: Re: Group for old computers
X-Newsreader: TIN [version 1.2 PL2]
Organization: HNN UNIX Network
Message-ID: <1994Aug19.141201.20757@escape.widomaker.com>
References: <werme.776546437@alingo.zk3.dec.com> <11AUG199408483833@almach.caltech.edu> <32f64v$kds@nic.lth.se> <13AUG199410052681@almach.caltech.edu> <32q7m9$612@nic.lth.se> <7hDKkGakfSRE069yn@iol.ie> <32vavj$n12@uuneo.neosoft.com>
Date: Fri, 19 Aug 1994 14:12:01 GMT
Lines: 24
Xref: bigblue.oit.unc.edu alt.folklore.computers:72784 comp.sys.dec:22048 vmsnet.pdp-11:1490 alt.sys.pdp8:1012

Jerry Leslie (jleslie@dmccorp.com) wrote:

: And why the rumor that the name "Windows-NT" was a justification for the
: acronym "WNT", which is "VMS" transposed up by one letter ?  This was done 
: for the computer in the the movie "2001, a Space Odessy", HAL, which
: is "IBM" transposed down by one letter.

That is NOT the reason for the name HAL.  This is just a stupid rumor
that has been thoroughly dismissed by Arthur C. Clarke.


: --Gerald (Jerry) R. Leslie
:   Staff Engineer
:   Dynamic Matrix Control Corporation    (my opinions are my own)
:   P.O. Box 721648                       9896 Bissonnet
:   Houston, Texas 77272                  Houston, Texas, 77036
:   713/272-5065                          713/272-5200 (fax)
:   gleslie@isvsrv.enet.dec.com
:   jleslie@dmccorp.com
-- 
csh
---------------------------------------------------------------------------
shendrix@escape.widomaker.com (UUCP)     | Amd486/40 Linux system
shendrix@pcs.cnu.edu (Internet)          | Christopher Newport University


From mol@trurl.df.lth.se Sat Aug 20 14:05:11 EDT 1994
Article: 1013 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!news-feed-1.peachnet.edu!news.duke.edu!MathWorks.Com!europa.eng.gtefsd.com!howland.reston.ans.net!pipex!sunic!news.lth.se!mol
From: mol@trurl.df.lth.se (Magnus Olsson)
Newsgroups: alt.folklore.computers,alt.sys.pdp8,alt.sys.pdp11,alt.sys.pdp10,comp.sys.dec,alt.config
Subject: alt.sys.pdp10 created
Followup-To: alt.config,alt.sys.pdp10
Date: 20 Aug 1994 12:56:09 GMT
Organization: yacc - the Computer Society at Lund University and Lund Institute of Technology
Lines: 11
Message-ID: <334uh9$4c3@nic.lth.se>
NNTP-Posting-Host: trurl.df.lth.se
Xref: bigblue.oit.unc.edu alt.folklore.computers:72856 alt.sys.pdp8:1013 comp.sys.dec:22076 alt.config:38529

I've just sent out a newgroup message for alt.sys.pdp10.
It may take some time for the group to appear at your site. 

However, if it hasn't appeared at your site within a week you should
talk to your news administrator. If he/she hasn't received the newgroup
message, please email me and I'll try to fix it.

Magnus Olsson (mol@df.lth.se) / yacc computer club, Lund, Sweden
Work: Innovativ Vision AB, Linkoping (magnus.olsson@ivab.se)
Old adresses (may still work): magnus@thep.lu.se, thepmo@selund.bitnet
PGP key available via finger (to df.lth.se) or on request.


From moisan@bronze.lcs.mit.edu Wed Aug 24 03:00:02 EDT 1994
Article: 1014 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!news-feed-1.peachnet.edu!news.duke.edu!eff!usenet.ins.cwru.edu!howland.reston.ans.net!spool.mu.edu!bloom-beacon.mit.edu!ai-lab!bronze.lcs.mit.edu!not-for-mail
From: moisan@bronze.lcs.mit.edu (David Moisan)
Newsgroups: sci.electronics.repair,comp.sys.dec,comp.sys.dec.micro,alt.sys.pdp8
Subject: DEC VR201 monitor modifications?
Followup-To: sci.electronics.repair
Date: 21 Aug 1994 19:13:02 -0400
Organization: MIT LCS guest machine
Lines: 18
Message-ID: <338n1u$4gf@bronze.lcs.mit.edu>
NNTP-Posting-Host: bronze.ai.mit.edu
Summary: Need to turn off monitor while DECmate still runs--possible?
Xref: bigblue.oit.unc.edu sci.electronics.repair:1971 comp.sys.dec:22102 comp.sys.dec.micro:3082 alt.sys.pdp8:1014

I've a DECmate that I expect to use as a TCP/IP router for my amateur radio
setup.  Problem is, I will need to run it 24hrs a day and since the monitor
is always on when the system is running, it will kill the CRT before very
long.  (I replaced the original monitor on the DM for just this reason.)

I'd been thinking of adding a small toggle switch to control the +12V
supply in the monitor;  however, DEC warns that unplugging the monitor
while the system is running will cause damage.  Would simply removing 
the monitor's power cause any problems?  
 
Any suggestions appreciated and thanks much,
 
Dave
-- 
| David Moisan, N1KGH    /^\_/^\   moisan@bronze.lcs.mit.edu      |
| 86 Essex St. Apt #204 ( o ^ o )  n1kgh@amsat.org                |
| Salem. MA 01970-5225     | |     ce393@cleveland.freenet.edu    |
|                                                                 |


From iyoung@alpha.wright.edu Wed Aug 24 03:00:24 EDT 1994
Article: 1015 of alt.sys.pdp8
Newsgroups: alt.folklore.computers,comp.sys.dec,vmsnet.pdp-11,alt.sys.pdp11,alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!news-feed-1.peachnet.edu!news.duke.edu!eff!wariat.org!malgudi.oar.net!mercury.wright.edu!iyoung
From: iyoung@alpha.wright.edu (Ian Young)
Subject: Re: Group for old computers
Message-ID: <Cux1L9.ED9@mercury.wright.edu>
Sender: news@mercury.wright.edu (USENET News System)
Organization: Wright State University, Dayton, Ohio.
References: <7hDKkGakfSRE069yn@iol.ie> <32vavj$n12@uuneo.neosoft.com> <1994Aug19.141201.20757@escape.widomaker.com>
Date: Mon, 22 Aug 1994 02:58:21 GMT
Lines: 38
Xref: bigblue.oit.unc.edu alt.folklore.computers:72967 comp.sys.dec:22104 vmsnet.pdp-11:1506 alt.sys.pdp8:1015

In article <1994Aug19.141201.20757@escape.widomaker.com> shendrix@escape.widomaker.com (Shannon Hendrix) writes:
>Jerry Leslie (jleslie@dmccorp.com) wrote:
>
>: And why the rumor that the name "Windows-NT" was a justification for the
>: acronym "WNT", which is "VMS" transposed up by one letter ?  This was done 
>: for the computer in the the movie "2001, a Space Odessy", HAL, which
>: is "IBM" transposed down by one letter.
>
>That is NOT the reason for the name HAL.  This is just a stupid rumor
>that has been thoroughly dismissed by Arthur C. Clarke.
>
>
>: --Gerald (Jerry) R. Leslie
>:   Staff Engineer
>:   Dynamic Matrix Control Corporation    (my opinions are my own)
>:   P.O. Box 721648                       9896 Bissonnet
>:   Houston, Texas 77272                  Houston, Texas, 77036
>:   713/272-5065                          713/272-5200 (fax)
>:   gleslie@isvsrv.enet.dec.com
>:   jleslie@dmccorp.com
>-- 
>csh
>---------------------------------------------------------------------------
>shendrix@escape.widomaker.com (UUCP)     | Amd486/40 Linux system
>shendrix@pcs.cnu.edu (Internet)          | Christopher Newport University

Heuristic ALgorithmic
H +       AL = HAL (but the IBM rumour sounds better)
-- 
Ian, barely speaking even for himsel  | "Riding a Harley Hog with Uma |     /
iyoung@alpha.wright.edu               | Thurman: That's heaven"       |
"the guy who tries to be funny, but   | -K. D. Lang-                  |  
everybody laughs at."
-- 
+============+==================+==========================+================
Ian, barely speaking even for himself | "Riding a Harley Hog with Uma      /
iyoung@alpha.wright.edu               | Thurman: That's heaven" ........../
"the guy who tries to be funny, but   | -K. D. Lang-           /


From spbcajk@ucl.ac.uk Wed Aug 24 03:00:49 EDT 1994
Article: 1016 of alt.sys.pdp8
Newsgroups: alt.folklore.computers,comp.sys.dec,vmsnet.pdp-11,alt.sys.pdp11,alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!news-feed-1.peachnet.edu!emory!swrinde!pipex!ibmpcug!miclon!uknet!bcc.ac.uk!link-1.ts.bcc.ac.uk!spbcajk
From: spbcajk@ucl.ac.uk (Mr Andrew John Kale)
Subject: Re: Group for old computers
Message-ID: <1994Aug22.124247.33439@ucl.ac.uk>
Date: Mon, 22 Aug 1994 12:42:47 GMT
References: <werme.776546437@alingo.zk3.dec.com> <11AUG199408483833@almach.caltech.edu> <32f64v$kds@nic.lth.se> <13AUG199410052681@almach.caltech.edu> <32q7m9$612@nic.lth.se> <7hDKkGakfSRE069yn@iol.ie> <32vavj$n12@uuneo.neosoft.com>
Organization: University College London
Lines: 22
Xref: bigblue.oit.unc.edu alt.folklore.computers:72988 comp.sys.dec:22121 vmsnet.pdp-11:1508 alt.sys.pdp8:1016

jleslie@dmccorp.com (Jerry Leslie) writes:

>And why the rumor that the name "Windows-NT" was a justification for the
>acronym "WNT", which is "VMS" transposed up by one letter ?  This was done 
>for the computer in the the movie "2001, a Space Odessy", HAL, which
>is "IBM" transposed down by one letter.

In his defence, it must be noted that Arthur C. Clarke has always denied all 
knowledge of this at the time; he puts it down to serendipity. Wouldn't
you - after all, particularly in this day and age, who wants to admit that
they're one step behind Big Blue?

                                Cheers
                /================\		
                \======\    /====/	
                       #    #	
                       #    #   /========\  /===========\
                       #    #   #   @@   #  #    ===    # 
                /==\  /     #   #   @@   #  #   #   #   #
                #   ==      /   #   @@   #  #   #   #   #
                \=========/     \========/  \===/   \===/
						              spbcajk@ucl.ac.uk


From mol@trurl.df.lth.se Wed Aug 24 03:01:20 EDT 1994
Article: 1017 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!gatech!howland.reston.ans.net!EU.net!sunic!news.lth.se!mol
From: mol@trurl.df.lth.se (Magnus Olsson)
Newsgroups: alt.sys.pdp10,alt.sys.pdp8,alt.sys.pdp11,vmsnet.pdp11,alt.folklore.computers,comp.sys.dec
Subject: Welcome to alt.sys.pdp10
Followup-To: alt.sys.pdp10
Date: 22 Aug 1994 17:21:43 GMT
Organization: yacc - the Computer Society at Lund University and Lund Institute of Technology
Lines: 24
Message-ID: <33amr7$itr@nic.lth.se>
NNTP-Posting-Host: trurl.df.lth.se
Xref: bigblue.oit.unc.edu alt.sys.pdp8:1017 alt.folklore.computers:73015 comp.sys.dec:22133

Welcome to the new newsgroup alt.sys.pdp10!

This is a newgroup for the discussion of DEC's PDP-10 and DEC-20
computers and clones by other manufacturers, their hardware and
architecture, their software and operating systems, and emulators
running on other machines. 

Also it's a place for telling your "war stories" involving these
machines, anecdotes about the '10-based hacker culture (including the
ITS community); a place for old hackers to reminisce about the old
days, and for younger hackers to learn about these legendary things. 

And, finally, it's a place for the priests of the 36-bit creed to
combat the modern heresy that a machine must have a word length
that's a multiple of 8 :-).

P.S. If your site isn't receiving alt.sys.pdp10 within a week or so,
talk to your news admin. If he/she hasn't received any newgroup
message, please contact me. 

Magnus Olsson (mol@df.lth.se) / yacc computer club, Lund, Sweden
Work: Innovativ Vision AB, Linkoping (magnus.olsson@ivab.se)
Old adresses (may still work): magnus@thep.lu.se, thepmo@selund.bitnet
PGP key available via finger (to df.lth.se) or on request.


From MLEWIS@P06.dasd.honeywell.com Wed Aug 24 03:01:35 EDT 1994
Article: 1018 of alt.sys.pdp8
Newsgroups: alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!news.duke.edu!MathWorks.Com!europa.eng.gtefsd.com!howland.reston.ans.net!news.moneng.mei.com!uwm.edu!src.honeywell.com!the-star.honeywell.com!cs0.dasd.honeywell.com!P06.dasd.honeywell.com!MLEWIS
From: MLEWIS@P06.dasd.honeywell.com
Subject: PDP-8 emulator
Message-ID: <MLEWIS.5.777584242@P06.dasd.honeywell.com>
Keywords: PDP-8 emulator
Lines: 7
Sender: news@cs0.dasd.honeywell.com
Organization: Honeywell, INC. DASD
Date: Mon, 22 Aug 1994 19:37:22 GMT

  I'm looking for a good freeware/shareware/commercial PDP-8 emulator.  It
would be great if it runs on a PC, but I do have access to other
types of machines.
Michael Lewis    +  mlewis@p06.dasd.honeywell.com  +   Be afraid...
Sr. Programmer   +                                 +
Honeywell DAS    +       mlewis@abq-ros.com        +   Be VERY afraid...
ABQ, NM          +                                 +


From jones@pyrite.cs.uiowa.edu Wed Aug 24 03:02:12 EDT 1994
Article: 1019 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!news.duke.edu!convex!cs.utexas.edu!howland.reston.ans.net!math.ohio-state.edu!hobbes.physics.uiowa.edu!news.uiowa.edu!news
From: jones@pyrite.cs.uiowa.edu (Douglas W. Jones,201H MLH,3193350740,3193382879)
Newsgroups: alt.sys.pdp8
Subject: Re: PDP-8 emulator
Date: 22 Aug 1994 21:53:07 GMT
Organization: University of Iowa, Iowa City, IA, USA
Lines: 23
Distribution: world
Message-ID: <33b6o3$qu3@nexus.uiowa.edu>
References: <MLEWIS.5.777584242@P06.dasd.honeywell.com>
NNTP-Posting-Host: pyrite.cs.uiowa.edu

From article <MLEWIS.5.777584242@P06.dasd.honeywell.com>,
by MLEWIS@P06.dasd.honeywell.com:
>   I'm looking for a good freeware/shareware/commercial PDP-8 emulator.

What peripherals do you want emulated?  How fancy a front panel do you
want (will a textual approximation do, or do you want blinking lights).

If you want blinking lights emulated on an X-terminal from a UNIX
environment, and if full support for TTY (on your console terminal
window) and high speed paper tape reader/punch (on disk files) will
satisfy you, I have what you want.  Reports are that it runs well
under Linux on an IBM PC, even, as long as you have X.  My emulator
also supports RX01 diskettes (as apecial format disk files), but
that's not fully debugged.  I'll E-mail it on demand.

There are some good emulators written for the IBM PC also,
Bill Haygood <billh@comtch.iea.com> has a nice one, with good
support for more devices, I believe, but as I understand it, the
graphics aren't so flashy.  Anyway, the faq has pointers to various
stuff on FTP archives you might want to look at.

				Doug Jones
				jones@cs.uiowa.edu


From root@bass.cse.bris.ac.uk Wed Aug 24 03:02:25 EDT 1994
Article: 1020 of alt.sys.pdp8
Newsgroups: alt.folklore.computers,comp.sys.dec,vmsnet.pdp-11,alt.sys.pdp11,alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!news-feed-1.peachnet.edu!news.duke.edu!MathWorks.Com!europa.eng.gtefsd.com!howland.reston.ans.net!agate!doc.ic.ac.uk!lyra.csx.cam.ac.uk!warwick!bsmail!uns.bris.ac.uk!root
From: root@bass.cse.bris.ac.uk (Super-User)
Subject: Re: Group for old computers
In-Reply-To: spbcajk@ucl.ac.uk's message of Mon, 22 Aug 1994 12:42:47 GMT
Message-ID: <ROOT.94Aug23130534@bass.cse.bris.ac.uk>
Sender: usenet@info.bris.ac.uk (Usenet news owner)
Nntp-Posting-Host: bass.cse.bris.ac.uk
Organization: Computing Service, University of Bristol, GB.
References: <werme.776546437@alingo.zk3.dec.com> <11AUG199408483833@almach.caltech.edu>
	<32f64v$kds@nic.lth.se> <13AUG199410052681@almach.caltech.edu>
	<32q7m9$612@nic.lth.se> <7hDKkGakfSRE069yn@iol.ie>
	<32vavj$n12@uuneo.neosoft.com> <1994Aug22.124247.33439@ucl.ac.uk>
Date: Tue, 23 Aug 1994 12:05:34 GMT
Lines: 13
Xref: bigblue.oit.unc.edu alt.folklore.computers:73120 comp.sys.dec:22159 vmsnet.pdp-11:1518 alt.sys.pdp8:1020

In article <1994Aug22.124247.33439@ucl.ac.uk> spbcajk@ucl.ac.uk (Mr Andrew John Kale) writes:

   In his defence, it must be noted that Arthur C. Clarke has always denied all 
   knowledge of this at the time; he puts it down to serendipity.
                                                     -----------

That's presumably why he lives in Sri Lanka -- a ready-made excuse.
  
--
 Kit Powell
  c.j.powell@bristol.ac.uk +44 117 9287864 (fax +44 117 9291576)
  Computing Service, University of Bristol, Bristol BS8 1UD, GB


From werme@alingo.zk3.dec.com Wed Aug 24 03:06:23 EDT 1994
Article: 1021 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!gatech!howland.reston.ans.net!europa.eng.gtefsd.com!MathWorks.Com!news.duke.edu!alingo.zk3.dec.com!werme
From: werme@alingo.zk3.dec.com (Eric Werme)
Newsgroups: alt.folklore.computers,alt.sys.pdp8,alt.sys.pdp11,comp.society.folklore
Subject: Re: DEC roots of PIP, DDT, etc. (& early OS/8)
Followup-To: comp.society.folklore
Date: 23 Aug 1994 15:21:03 -0400
Organization: Digital Equipment Corporation
Lines: 72
Sender: jfurr@acpub.duke.edu
Approved: jfurr@acpub.duke.edu
Message-ID: <werme.777579770@alingo.zk3.dec.com>
NNTP-Posting-Host: bio2.acpub.duke.edu
Xref: bigblue.oit.unc.edu alt.folklore.computers:73163 alt.sys.pdp8:1021 comp.society.folklore:321


Hear are two replies I received from people much closer to those early roots
than I.

------------------------------------------------------------

From: "John Green" <john_green@jericho.mc.com>

You don't have to appeal to CJL.
==========
I believe (CJL - help!) that the PDP-8 folks writing OS/8 (TS/8?)
picked up the names and general command syntax from their PDP-10
exposure.  Many of those people moved to RT-11 and copied all of
that.  A DDT for the -11 came from CMU in the mid 1970s, but I'm
not sure if that ever became a distributed piece of code either
through DEC or DECUS.
==========
    What do you mean PDP-8 folks writing OS/8? It was a one man project
conceived and implemented by my roommate Richard F Lary. He called it the First
Upward Compatible Keyboard Monitor (FUCK Monitor). There was an intention,
perhaps only humorous, to write a PDP-15 Second Upward Compatible Keyboard
Monitor (SUCK Monitor).
    He took the idea to his boss on Wednesday. His boss said to start work on
it as a background project and keep his regular work on schedule. If he ever
got within 6 months of finishing they would assign a tech writer to it and
consider releasing it.
    Richie took that as a challenge and demoed the system to his boss the
following Monday. It was complete enough to load a primitive PIP off DEC Tape
which would give a prompt and copy files. Of course it took another year of
work before Programming System/8 (PS/8) was released. At Eli Glaser's (a Long
Island NY salesman) suggestion the system was renamed OS/8 as Eli said he could
sell more machines with an Operating System than he could with a Programming
System.
    The intention of the project was to be able to have an ASR-33 in an empty
room and give a user a Turing Test to see if he could determine whether it was
connected to PS/8 or TOPS-10.
[werme nitpick: I'm not certain about 1971, but I know in 1969 (see below)
 "TOPS-10" wasn't shipping.  Ihe OS was called merely the "PDP-10 Monitor".]

Regards,
John C

------------------------------------------------------------

From: lary@ssag.cxo.dec.D5NET.dec.com (A cowflop in the cybernetic meadow)

John's information is fairly accurate, a coupla nits:

- I wrote the first draft of the FUCK Monitor, which became the BLEEP Monitor,
which was released as PS/8 (Programming System/8, my term, because I didn't
think any system which didn't enable interrupts should be called an OS), which
became OS/8 during the Nixon Wage/Price Freeze in 1971 (because, um, if we
called it PS/8 Release 2 we couldn't charge a higher price for it). I didn't
write the released product alone, however, I had help from a guy named Ed
Friedman and another guy named Paul <memory loss>. 

- Digital had a program development system for the PDP-8 at the time (1969) but
it was bad, bad, bad. We acquired the rights to a system named CPS (Cooley
Programming System, developed at Cooley Lab at the University of Michigan)
in exchange for some hardware and I was given the job of productizing it. CPS
was miles better than what we had, but it had LOTS of internal restrictions and
its user interface was alien (modeled on TSS/360, which is what they had at
Michigan) so I decided to scrap it instead. My manager, Chuck Conley, covered
me by telling the rest of the company that we were just making some small
changes to CPS to make it more compatible.

- Actually, there wasn't a DDT on the PDP-8 for a long time; we couldn't afford
the room for the symbol table. We used ODT, Octal Debugging Technique, with
similiar syntax to DDT but no symbols. No big deal when a large program (like
our Fortran compiler) was less than 10KB...

							Richie


From svm@kozmix.xs4all.nl Wed Aug 24 03:07:27 EDT 1994
Article: 1022 of alt.sys.pdp8
Newsgroups: alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!rutgers!cis.ohio-state.edu!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!EU.net!sun4nl!hacktic!kozmix.xs4all.nl!svm
From: svm@kozmix.xs4all.nl (Sander van Malssen)
Subject: Re: PDP-8 emulator
Reply-To: svm@kozmix.xs4all.nl
Organization: Kozmic Egg Productions, Gouda, Netherlands
Message-ID: <Cv06xG.6JA@kozmix.xs4all.nl>
References: <MLEWIS.5.777584242@P06.dasd.honeywell.com> <33b6o3$qu3@nexus.uiowa.edu>
Date: Tue, 23 Aug 1994 21:46:27 +0200 (MET DST)
Lines: 20

jones@pyrite.cs.uiowa.edu (Douglas W. Jones,201H MLH,3193350740,3193382879) writes:
> There are some good emulators written for the IBM PC also,
> Bill Haygood <billh@comtch.iea.com> has a nice one, with good
> support for more devices, I believe, but as I understand it, the
> graphics aren't so flashy.  Anyway, the faq has pointers to various
> stuff on FTP archives you might want to look at.

Haygood's emulator has the added advantage that it comes with a disk
pack image full of goodies. If someone wants to build it on a UN*X
box, mail me for an improved version of the screen handling code.

(BTW, the /pub/academic/computer-science/history/pdp-8/emulators/new
dir on sunsite.unc.edu is a later version of .../emulators/haygood,
so don't bother downloading both dirs.)

Cheers,
Sander
-- 
Sander van Malssen
svm@kozmix.xs4all.nl


From jones@pyrite.cs.uiowa.edu Wed Aug 24 03:07:55 EDT 1994
Article: 1023 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!rutgers!cis.ohio-state.edu!math.ohio-state.edu!hobbes.physics.uiowa.edu!news.uiowa.edu!news
From: jones@pyrite.cs.uiowa.edu (Douglas W. Jones,201H MLH,3193350740,3193382879)
Newsgroups: alt.sys.pdp8
Subject: PDP-8 systems available!
Date: 23 Aug 1994 21:21:54 GMT
Organization: University of Iowa, Iowa City, IA, USA
Lines: 24
Distribution: world
Message-ID: <33dp9i$58h@nexus.uiowa.edu>
NNTP-Posting-Host: pyrite.cs.uiowa.edu

Chuck Taylor <ctaylor@college.antioch.edu> of Antioch College in Ohio
says that he has a pair of PDP-8/E systems to dispose of.

One is a lab8/e system (green paint job on the front panel), the other
is a PDP-8/e.  He listed the following options as being present on
both machines (his list wasn't complete):

M8350	KA8E	External positive I/O bus interface
M884	KG8E	Parity Generator Detector for DP8E
M8655	KL8JA	Terminal Control (UART based substitute for M8650)
M848	KP8E	Power fail and auto-restart

He also says there is a paper tape reader/punch and 25 or more rolls of
psper tape, plus many "flip'n'file" plastic paper-tape holders.

The system was supposed to be functional when he got it, but it hasn't
been tested recently.

This is an excellent chance for folks in the east-central states to get
their hands on a machine.  If you want to arrange to pick up one of
these machines, please reply directly to Chuck Taylor, not to me.

				Doug Jones
				jones@cs.uiowa.edu


From grg@boombox.micro.umn.edu Wed Aug 24 17:27:03 EDT 1994
Article: 1024 of alt.sys.pdp8
Newsgroups: alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!news.duke.edu!MathWorks.Com!panix!zip.eecs.umich.edu!umn.edu!news
From: "George Gonzalez" <grg@boombox.micro.umn.edu>
Subject: Re: PDP-8 emulator
Message-ID: <52571.grg@boombox.micro.umn.edu>
X-Minuet-Version: Minuet1.0_Beta_17a4
Sender: news@news.cis.umn.edu (Usenet News Administration)
Nntp-Posting-Host: x130-199.open.umn.edu
X-Popmail-Charset: English
Organization: University of Minnesota, Twin Cities
Date: Wed, 24 Aug 1994 15:56:39 GMT
Lines: 17

On Tue, 23 Aug 1994 21:46:27 +0200 (MET DST, 
Sander van Malssen  <svm@kozmix.xs4all.nl> wrote:

>jones@pyrite.cs.uiowa.edu (Douglas W. Jones,201H MLH,3193350740,3193382879) writes:
>> There are some good emulators written for the IBM PC also,
>> Bill Haygood <billh@comtch.iea.com> has a nice one, with good
>> support for more devices, I believe, but as I understand it, the
>> graphics aren't so flashy.  Anyway, the faq has pointers to various
>> stuff on FTP archives you might want to look at.
>

Has anyone gotten Haygood's emulator to compile and run under MSDOS?
It seems to use some large arrays that make Borland C choke.
Plus there are a few typos in the CRT library that don't compile at all.

Respond by e-mail,  please.


From smj@sdf.lonestar.org Sat Aug 27 03:50:43 EDT 1994
Article: 1025 of alt.sys.pdp8
Newsgroups: alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!news.duke.edu!MathWorks.Com!europa.eng.gtefsd.com!howland.reston.ans.net!cs.utexas.edu!convex!egsner!sdf!smj
From: smj@sdf.lonestar.org (Stephen M. Jones)
Subject: decmateIII forsale
Message-ID: <Cv3J2x.Dx3@sdf.lonestar.org>
Organization: sdf.lonestar.org - dallas, tx.. 1 + 214.248.9811
Distribution: usa
Date: Thu, 25 Aug 1994 15:01:34 GMT
Lines: 8


hello.  I am selling a working decmate three (includes monitor and keyboard 
of course)  I have some software from CL ftp site to include with it
as well (os/278, gte .. et cetera)  Please make an offer.


-- 
stephen m. jones ... smj@sdf.macross.org 


From Tonyquin@sixpints.demon.co.uk Tue Aug 30 04:11:36 EDT 1994
Article: 1026 of alt.sys.pdp8
Newsgroups: alt.sys.pdp8
From: tonyquin@sixpints.demon.co.uk (Tony Quinn)
Path: bigblue.oit.unc.edu!concert!news-feed-1.peachnet.edu!news.duke.edu!MathWorks.Com!udel!news.sprintlink.net!demon!sixpints.demon.co.uk!tonyquin
Subject: Re: PDP-8 emulator 
Distribution: world
References: <52571.grg@boombox.micro.umn.edu>
Organization: Total lack of.....
Reply-To: Tonyquin@sixpints.demon.co.uk
X-Newsreader: Simple NEWS 1.90 (ka9q DIS 1.21)
Lines: 17
Date: Sun, 28 Aug 1994 09:30:33 +0000
Message-ID: <778066233snz@sixpints.demon.co.uk>
Sender: usenet@demon.co.uk

In article <52571.grg@boombox.micro.umn.edu> grg@boombox.micro.umn.edu writes:

>
>Has anyone gotten Haygood's emulator to compile and run under MSDOS?
>It seems to use some large arrays that make Borland C choke.
>Plus there are a few typos in the CRT library that don't compile at all.
>
>Respond by e-mail,  please.

I seem to be having the same trouble, typos I can cope with, the large
arrays Mr Borland's finest can't!!!
--
--------------------------------------------------------------------------
                Tony Quinn ----- The Voice of Insanity

               replies to tonyquin@sixpints.demon.co.uk
--------------------------------------------------------------------------


From jones@pyrite.cs.uiowa.edu Tue Aug 30 04:12:16 EDT 1994
Article: 1027 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!news-feed-1.peachnet.edu!news.duke.edu!convex!cs.utexas.edu!math.ohio-state.edu!hobbes.physics.uiowa.edu!news.uiowa.edu!news
From: jones@pyrite.cs.uiowa.edu (Douglas W. Jones,201H MLH,3193350740,3193382879)
Newsgroups: alt.sys.pdp8
Subject: Re: PDP-8 emulator
Date: 28 Aug 1994 16:44:15 GMT
Organization: University of Iowa, Iowa City, IA, USA
Lines: 11
Distribution: world
Message-ID: <33qesv$ejo@nexus.uiowa.edu>
References: <778066233snz@sixpints.demon.co.uk>
NNTP-Posting-Host: pyrite.cs.uiowa.edu

>>Has anyone gotten Haygood's emulator to compile and run under MSDOS?
>>It seems to use some large arrays that make Borland C choke.
>>Plus there are a few typos in the CRT library that don't compile at all.

Well, try mine then, in the non-X-windows version.  It has no big arrays,
but it has one module, ttyaccess.c that will need rewriting to run under
MSDOS (my version is for UNIX).  All ttyaccess does is take over the
keyboard for single character at a time polled use.

				Doug Jones
				jones@cs.uiowa.edu


From lhauser@rs6a.wln.com Tue Aug 30 04:13:20 EDT 1994
Article: 1028 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!news.duke.edu!eff!news.kei.com!rs6a.wln.com!rs6a.wln.com!lhauser
From: lhauser@rs6a.wln.com (Williams Kastner Gibbs)
Newsgroups: alt.sys.pdp8
Subject: Re: PDP-8 emulator
Date: 29 Aug 1994 15:26:03 GMT
Organization: WLN
Lines: 17
Distribution: world
Message-ID: <33sumb$14lq@rs6a.wln.com>
References: <33qesv$ejo@nexus.uiowa.edu>
NNTP-Posting-Host: rs6a.wln.com
X-Newsreader: TIN [version 1.1 PL8]

Douglas W. Jones,201H MLH,3193350740,3193382879 (jones@pyrite.cs.uiowa.edu) wrote:
: >>Has anyone gotten Haygood's emulator to compile and run under MSDOS?
: >>It seems to use some large arrays that make Borland C choke.
: >>Plus there are a few typos in the CRT library that don't compile at all.

: Well, try mine then, in the non-X-windows version.  It has no big arrays,
: but it has one module, ttyaccess.c that will need rewriting to run under
: MSDOS (my version is for UNIX).  All ttyaccess does is take over the
: keyboard for single character at a time polled use.

: 				Doug Jones
: 				jones@cs.uiowa.edu

Doug... how do we get it?  I'd like to try it.

Lee


From jones@pyrite.cs.uiowa.edu Tue Aug 30 04:13:57 EDT 1994
Article: 1029 of alt.sys.pdp8
Path: bigblue.oit.unc.edu!concert!rutgers!koriel!cs.utexas.edu!math.ohio-state.edu!hobbes.physics.uiowa.edu!news.uiowa.edu!news
From: jones@pyrite.cs.uiowa.edu (Douglas W. Jones,201H MLH,3193350740,3193382879)
Newsgroups: alt.sys.pdp8
Subject: Re: PDP-8 emulator
Date: 29 Aug 1994 16:40:49 GMT
Organization: University of Iowa, Iowa City, IA, USA
Lines: 10
Distribution: world
Message-ID: <33t32h$m4b@nexus.uiowa.edu>
References: <33sumb$14lq@rs6a.wln.com>
NNTP-Posting-Host: pyrite.cs.uiowa.edu

From article <33sumb$14lq@rs6a.wln.com>,
by lhauser@rs6a.wln.com (Williams Kastner Gibbs):
> 
> Doug... how do we get it?  I'd like to try it.

For now, I'm distributing a uuencoded compressed UNIX-style shell archive
by E-mail.  You asked for it, so I already E-mailed it your way.

				Doug Jones
				jones@cs.uiowa.edu


