


		OS/78 Version 4 System Generation

1.0  General Information

System generation for OS/78 requires two system devices. In the ex-
amples that follow, the "master" system was RK05-based, the object
system was either RL01/RL02 or RX01/RX02. System generation also re-
quires a PDP-8/e, OS/8 Version 3D, and MACREL/LINK Version 2 (or
later) for the assembly and linking of the CCL program modules, the
FORMAT.SV utility, and FORLIB.RL. The batch files provided are:

CCLGEN.BI  Assembles and links CCL
FORMAT.BI  Assembles the MACREL version of FORMAT
FORLIB.BI  Assembles and links FORLIB.RL
BLDRxx.BI  Uses BUILD.SV to create a "system head"
RxxFIN.BI  Finishes transfer of image files to the new system.

NOTE: The above files must run under OS/8 on a PDP-8/e; the balance
are supported by the VT278.

BASGEN.BI  Assembles BASIC
FORGEN.BI  Assembles FORTRAN run-time and monitor
HANGEN.BI  Assembles the handlers and creates the .HN image files
UTLGEN.BI  Assembles and creates the Utility program image files

The files OS8V4.PA and CDV4.PA are assembled individually. The [binary]
object files produced are then submitted to BUILD.SV to construct the
"system head" and ABSLDR.SV.

2.0  System Generation

For the generation of this particular version of OS/78, the master
system resided on an RK05 with an OS/8 V3D monitor. This system also
contained the necessary MACREL/LINK utilities for assembly of sources
written in MACREL. The balance of the .PA (PAL8 assembly language
sources) were stored on an RL02. Executable image files were stored
on the master as .V4, .HN or as applicable for special cases, for
example BASIC.OV.

2.1  Utility, Monitor and Language Image Files.

Assemble the Utilities, Monitor and Langage image files with BASGEN.BI,
FORGEN.BI, HANGEN.BI, and UTLGEN.BI. Move the image files to the master.
Remember OS/78 does not preserve successive file generations so any .SV
utility moved to the master will replace the OS/8 file of the same name
and may not be compatible with the OS/8 monitor. Move BUILD.PA to the
master.

2.2  CCL, FORLIB and FORMAT.

If no changes to any of the FORLIB modules (.RA) were made, move the
FORTRAN library FORLIB.RL to the master system. If changes were made,
assemble and link the new FORLIB.RL. Assemble and link CCL; assemble
FORMAT. Both image files are saved as "filename.V4".

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2.3  Creating the "System Head".

The term "system head" describes those OS/78 image files that are per-
manently resident in blocks 0, and 7-67, plus ABSLDR.SV. Blocks 0 and 66
will contain the system device handler. The system head will also contain
the device handlers that will be resident on the system. These may be
replaced later with "SET HANDLER old device<new device", but the slots
must be reserved at this point, since SET does not allow the insertion
of handlers, only the replacement. Also, the SET handler replacement
alogrithm requires that all handlers be two-page handlers with no
more than two co-resident devices. OS/8 can support an RL02 handler
with four co-resident devices; OS/78 is limited to two. BAT:, LPSV:
and VXA0: are actually one-page handlers, but for OS/78 they are de-
clared to be two pages, and are so treated by SET.

You may use a previously "run" version of BUILD.SV to insert or re-
place handlers in the new system head, but to build the image files
that will comprise the Monitor, Command Decoder, User Service Routine,
ODT, and ABLSDR.SV, you will need an unused assembly of BUILD.PA.
Assemble BUILD and save as BUILDV.SV for the batch files provided in
this system.

Modify BLDRxx.BI to include the list of handlers you want. These hand-
lers must reside on the master SYS: device and be binary (not save
image) files with the .BN extension. The $BUILD command (not to be
confused with the BUILD program) requires the .BN files that will
be used to create the monitor. The first file is OS8V4.BN in this
example, but may be renamed to anything, so long as it is still the
OS/78 monitor, has a .BN extension, and resides on SYS:. The de-
fault device for BUILD.SV is DSK:, but for OS/78 DSK=SYS. The second
file that will be read by the $BUILD command is for the Command
Decoder and ABLSDR.SV. Again, the file name CDV4 is not required,
but the binary file must be generated from CDV4.PA.

When the $BOOT command is given, BUILD will construct the system
head. The date for ABSLDR.SV is generated from a fixed table in
OS8V4.PA at the tag "DPROPR". Modifying "VERDATE" in OS8V4.PA will
change the date from the fixed entry.

See the OS/8 System Reference Manual for further information about
BUILD.SV.

2.4  Finalization.

After the BUILD program has run its course, reboot the master 
system and submit RxxFIN.BI to finish the transfer of image files.
Most OS/78 features are defaults; however, "SET SYS VT278" for VT278
systems and "SET TTY SCOPE" for all VDT-console systems is required.

3.0  Alternative Methods

3.1  Using PIP.SV.

If the system head area has not undergone revision, and the system
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built will have the same system device as the current system, the
"older" method of using PIP to transfer the system head may be 
used. The command ".R PIP" calls the command decoder processor to
allow entry of input and output file specifications. The /Y option
transfers the system head, but does not transfer the directory, or
any files. See the OS/8 System Reference Manual for a complete de-
scription of PIP and options.

3.2  Using SET SYS DEVICE.

In OS/78 V4, the command "SET SYS DEVICE old<new" will transfer the
current system head to the new device, inserting the proper system
handler in the process. Provided no changes were made to the system
head files, this process is much quicker than using the BUILD batch
files. For more information on this command see ".HELP SET" or the
OS/78 V4 User's Guide.

