From article <3marmn$8qe@lyra.csx.cam.ac.uk>,
by ard12@eng.cam.ac.uk (A.R. Duell):
> 
> You can link the M8650 to a teletype, which has a paper tape 
> punch/reader. You'd only get 10cps, though :-(

Here is the complete "cheat sheet" for the M8650, including instructions
on how to run it at baud rates well above what you can push over a modem!

 - - - - - - - Snip - - - - - - -


Technical notes for the M8650 KL8E OMNIBUS asynchronous interface board

by Douglas Jones
jones@cs.uiowa.edu

The M8650 board supports asynchronous communications at a variety of
baud rates, with either an RS232 or a current loop interface.  The board
is, effectively, equivalent to a UART chip, but it is made with SSI and
MSI chips.  Most of the options that might be programmable in a modern
UART chip are available, but they are selected by jumpers or part
changes on the board.

General geography of the M8650 board:

      \\____//           \\____//          \\____//           \\____//
 ______||__||_____________||__||____________||__||_____________||__||_____
| o  ____        o   o              o  o    _         o   o   9 7531     o|
|   |_   |                         |_|     | |   _    _  o1_  o oooo  _   |
|     |  | |||||||| ||             [_]     | |  | |  | |Ho2 |   G 42 | |  |
|     |  |  O|||O|H H|                     |_|  | |  | | o| | o oooo | |  |
|     |  |  |   | H H             o1            |_|  |_| 3|_|10 86   |_|  |
|     | B|      + | |             2 _                                     |
|     | E|                _       o| |      _    _    _    _    _     _   |
|     | R|               | |      J| |     | |  | |  | |  | |  | |   | |  |
|    _| G|               | |      o|_|     | |  | |  | |  | |  | |   | |  |
|   |____|               |_|      3        |_|  |_|  |_|  |_|  |_|   |_|  |
|                                                                         |
|    _    _    _    _     _     _     _     _    _    _    _    _     _   |
|   | |  | |  | |  | |   | |   | |   | |   | |  | |  | |  | |  | |   | |  |
|   | |  | |  | |  | |   | |   | |   | |   | |  | |  | |  | |  | |   | |  |
|   |_|  |_|  |_|  |_|   |_|   |_|   |_|   |_|  |_|  |_|  |_|  |_|   |_|  |
|                                                                         |
|    _    _    _    _     _     _     _     _    _    _    _    _     _   |
|   | |  | |  | |  | |   | |   | |   | |   | |  | |  | |  | |  | |   | |  |
|   | |  | |  | |  | |   | |   | |   | |   | |  | |  | |  | |  | |   | |  |
|   |_|  |_|  |_|  |_|   |_|   |_|   |_|   |_|  |_|  |_|  |_|  |_|   |_|  |
|                                                                         |
|    _    _    _    _     _     _     _     _  oooooo _    _  oooooo  _   |
|   | |  | |  | |  | |   | |   | |   | |   | |       | |  | |        | |  |
|   | |  | |  | |  | |   | |   | |   | |   | | F E D | |  | | C B A  | |  |
|   |_|  |_|  |_|  |_|   |_|   |_|   |_|   |_|       |_|  |_|        |_|  |
|                                              oooooo         oooooo      |
|_                __||               _||               __||              |
  |              |   |              |  |              |   |              |
  |______________|   |______________|  |______________|   |______________|

Given an M8650 board, various optional parts and jumpers must be inspected
and possibly changed prior to any use of the board.  The following sections
treat the primary options that limit the range of baud rates supported,
that select a particular rate, and that select the I/O device addresses
used for the board.

1) General baud rate considerations

      \\____//           \\____//
 ______||__||_____________||__||___________
| o  ____        o   o              o  o
|   |_   |                         |_|
|     |  | |||||||| ||             [_]<Crystal
|     |  |  O|||O|H H|                    14.418 MHz for 110 baud
|     |  |  |   | H H                     19.6608 MHz for all others.
|     | B|      + | |                     (in the latter case, the
|     | E|      ^                         board is designated M8650 YA)
|     | R|  Unless the board is to be
|    _| G|  used with a 110 baud current  The CTS MP196 19.6608 MHz
|   |____|  loop interface, this 0.47 uf  crystal, sold by DigiKey as
            capacitor may be removed.     part CTX090 works here.
            If the board is to be used
            with a current loop interface
            at over 110 baud, this must
            be halved for every doubling
            of the baud rate, but it is
            usual to just remove it.


2) Jumpering for data format               \\____//           \\____//
                                   _________||__||_____________||__||_____
                                    o  o    _         o   o   9 7531     o|
                                   |_|     | |   _    _  o1_  o oooo  _   |
                                   [_]     | |  | |  | |Ho2 |   G 42 | |  |
                                           |_|  | |  | | o| | o oooo | |  |
                 Jumper group J > o1            |_|  |_| 3|_|10 86   |_|  |
                                  2 _                    ^
         The factory installed    o| |      Jumper group H
         jumper (a zero ohm       J| |
         resistor between lugs    o|_|  The factory installed jumper (zero
         2 and 3) gives 2 stop    3     ohm resistor) between lugs 1 and 2
         bits.  Cut it and solder       gives the same baud rate for transmit
         a jumper from lug 1 to 2       and receive.  Consult DEC's drawings
         for one stop bit.              For the effects of alternatives here.


3) Jumpering for a specific baud rate.     \\____//           \\____//
                                         ___||__||_____________||__||_____
                                                      o   o   9 7531     o|
       Jumper group G gives the baud rate        _    _  o1_  o oooo  _   |
                                                |E|  | |Ho2 |   G 42 |E|  |
       Only one jumper should be present in     |2|  | | o| | o oooo |0|  |
       this group!                              |2|  |_| 3|_|10 86   |5|  |

           7 to 8  --  110 baud or 150 baud (depending on crystal)
           5 to 6  --  300 baud
           3 to 4  --  600 baud
           1 to 2  -- 1200 baud
           9 to 10 -- 2400 baud

       The following "unofficial" jumperings between pins of E05 (the IC
       in the upper right corner of the board) and the adjacent trace can
       be used for higher baud rates.  Electrically, these are all parts
       of jumper group G.                                    \\
                                                       __ __  \\
           8  --   4800 baud                         =|1  14|= ||<jumper
           9  --   9600 baud                         =|     |= || to this
           12 --  19200 baud                         =|   12|= || trace.
           14 --  38400 baud                         =| E05 |= ||
                                                     =|     |= ||
       In addition, long jumpers from pins of E22    =|    9|= ||
       to lug number 9 of jumper group G can be      =|____8|= ||
       used for even higher nonstandard rates.                 ||
       With these high rates, special short cables may
       be required!  The 314400 baud rate is pushing the limits
       of the frequency divider circuitry by cutting out most of the
       synchronous counter in E22 and shunting a 9.8 MHz signal
       directly into asynchronous circuitry rated at 10 MHz.
                                                                   9   7 5
           6  --  76800 baud    __ __                              o   o o
           2  -- 153600 baud  =|     |=     __ __       __ __
           3  -- 307200 baud  =|2    |=    |     |     |     |         G
                              =|3    |=    |     |     |     |
                              =| E22 |=    |     |     |     |     o   o o
                              =|     |=    |     |     |     |    10   8 6
                              =|6    |=    |     |     |     |
                              =|     |=    |     |     |     |
                              =|_____|=    |_____|     |_____|

4) Jumpering for the device address.

Jumper groups F, E, D, C, B and A give      _  oooooo _    _  oooooo  _   |
the device addresses for the input and     | |       | |  | |        | |  |
output ports.                              | | F E D | |  | | C B A  | |  |
                                           |_|       |_|  |_|        |_|  |
Each jumper group is physically                oooooo         oooooo      |
set up as follows:                   _||               __||              |
                                       |              |   |              |
   2  1                                |______________|   |______________|
   o  o

   |  |  factory installed zero ohm resistors for the
   O  O <default address.  Although they look like they
   |  |  go from 2 to 4 and 1 to 3, they don't!

   o  o
   4  3     The layout of the lugs in each jumper group is almost random!
            Here it is, in detail:

            - r  - t  r -      r -  r -  t -    r = receive address bit
             F    E    D        C    B    A     t = transmit address bit
            MD5  MD6  MD7      MD8  MD3  MD4    - = set bit to zero
            t +  r +  + t      + t  + t  + r    + = set bit to one

The following are popular device address jumperings:

03/04       o-o  o o  o o      o o  o-o  o-o  Note that the wiring of the
  console   |    | |  | |      | |    |    |  split lugs doesn't match the
  default!  |    | |  | |      | |    |    |  apparent layout of the zero
            o o  o o  o o      o o  o o  o o  ohm resistors for the default.

40/41       o-o  o-o  o-o      o-o  o o  o-o
  usual     |    |      |           |      |
  second    |    |      |           |      |
  TTY       o o  o o  o o      o-o  o-o  o o

65/66       o-o  o o  o-o      o o  o o  o o
  usual     |      |           | |  |    |
  serial    |      |           | |  |    |
  printer   o o  o-o  o-o      o o  o-o  o-o

The KL8E board allows arbitrary addresses for transmit and receive, but
by convention, the receive address should always be one less than
the transmit address.


5) Cables

      \\____//
 ______||__||______
| o  ____        o
|   |_   |
|     |  |    The cable plugged into the Berg connector determines whether
|     |  |    the board uses a current loop interface or an RS 232 interface.
|     |  |
|     | B|    The following connector hardware will mate with the Berg
|     | E|    connector on the board (DigiKey part numbers for AMP parts):
|     | R|
|    _| G|        ASC40G-ND  40 pin gold socket connector
|   |____|        ASSR40-ND  strain relief for above
                  ASPT40-ND  pull tab to make it easy to unplug

For an RS232 interface, you need the equivalent of DEC's BC01V cable.  This
mates with the Berg connector at one end and has a male DB25 connector at
the other end, in conformance with the RS232 specification.  For a current
loop interface, you need a 7008360 cable with a Mate-N-Lock connector at
the far end.
