Preface

This is a collection of insights into details of the B5500/B5700 handling.

A lot of information can be found in the vast amount of documentation about the Burroughs at bitsavers:

http://bitsavers.org/pdf/burroughs/B5000_5500_5700/

But, most are scanned printouts and cannot be scanned for keywords. It can be difficult to find the information you may be looking for. Even when you remember the information exits somewhere, you may not find it again. (I spent hours re-reading those PDFs.) Thanks to Paul Kimpel, I could proceed at some problematic points. But, when some issues arise again after several weeks, I might have forgotten the details used to solve it last time.

Now I will collect the issues and details here. For the time being, and until it gets too crowded, I will not use subfolders.

Expect this list to grow in the future.

Howto: Recompiling the MCP

Probably one of the things you want to do at some point, either to test the system with some heavy load, or to change options that are compiled in. It is actually a very simple thing to do, if you get all details right...

Some information first:

There are basically two different MCPs you may want to create.

• MCP - The standard MCP for batch processing. It has the option to have data communications, but this is NOT timesharing
• TSSMCP - The Time Sharing MCP. It can handle several 100 remote users with Teletype or Block Mode Terminals (in addition to batch processing)

The sources are on the SYSTEM tape. There are three files you have to deal with:

• SYMBOL/MCP or SYMBOL/TSSMCP - this is the main source, representing the initial release of the MARK level you are working at (for example MARK XIII)
• PATCHES/MCP or PATCHES/TSSMCP - those are the patches used to create SYMBOL/MCP or SYMBOL/TSSMCP from the PREVIOUS MARK level. You do NOT want to have those files on the disk, ?REMOVE them!
• PATCH/MCP or PATCH/TSSMCP - those are the patches to apply to SYMBOL/MCP or SYMBOL/TSSMCP to get the most current version of this MARK level. You usually want those patches applied

Further reading: Pages 30ff of B5700_System_Operation_Dec73 but be aware that this does not exactly apply to the MARK XIII release of the MCP

Compiling the TSSMCP

In order to have the patches applied and the options set as you desire, you need a CARD DECK to drop into the Card Reader. The CARD DECK will typically look like this for the TSSMCP (note that I included a local patch for the "WD" SPO command):

?REMOVE tssMCP/NEW13, tssMCP/STUFF13, PATCHES/tssMCP, PBD/=
?EXECUTE PATCH/MERGE
?FILE CARD = PMCARD
?DATA PMCARD
$@ CONFLICTS LIST MERGE ZIP
$. 23 PATCHES FOR tssMCP
$*EXECUTE ESPOL/DISK
$*FILE TAPE = SYMBOL/tssMCP DISK SERIAL
$*FILE LINE = tssMCP/LISTING PRINT BACK UP DISK
$*FILE DISK = tssMCP/NEW13 SERIAL
$*FILE STUFF = tssMCP/STUFF13 SERIAL
$*DATA CARD
$-
$ SET AUXMEM = TRUE
$ SET B6500LOAD = FALSE
$ SET BREAKOUT = FALSE
$ SET CHECKLINK = TRUE
$ SET DATACOM = TRUE
$ SET DEBUGGING = FALSE
$ SET DCLOG = FALSE
$ SET DCSPO =  TRUE
$ SET DISKLOG = FALSE
$ SET DFX = TRUE
$ SET DUMP = TRUE
$ SET INQUIRY = FALSE
$ SET RJE = FALSE
$ SET SAVERESULTS = TRUE
$ SET SHAREDISK = FALSE
$ SET STATISTICS = FALSE
$ SET TWXONLY = FALSE
$ SET DCP = FALSE
$ SET STUFF TAPE
$ TAPE STUFF LIST SINGLE PRT
$# PATCH NUMBER 999 FOR tssMCP CONTAINS 2 CARDS
    DAYS:::   "   SUN","   MON","  TUES","WEDNES",                      08340200
              " THURS","   FRI"," SATUR";                               08340300
$: THIS PATCH CAUSES THE DAY OF WEEK TO BE PRINTED CORRECTLY FOR
$: THE YEARS 2000 UNTIL 2099 (DL5UY 2018-05-23)
?END

(This is the deck I currently use to compile the TSSMCP MARK XIII. If you want to compile the batch MCP, just remove the "tss" in all places and change the "23" to "37".)

Hints:

• Don't forget to say "RN 1" at the SPO, otherwise the ESPOL compiler will not be started. (The PATCH/MERGE program produces a card deck which has to be read by a pseudo reader)
• the "$." line gives two informations to PATCH/MERGE:
  1. the number of patches to expect - it must match the actual number found!
  2. the name of the file with the patches (after the FOR)
  The latter will be prefixed with PATCHES/ or PATCH/ to generate the file name
• You can add local patches directly at the end of the card deck before the "?END"
• The output file is TSSMCP/NEW13 or MCP/NEW13. Make sure it is NOT the currently running MCP!
• After a successful compilation and when you want to try it out, ?CHANGE TSSMCP/NEW13 TO TSSMCP/TRY001 or something like that and do a CM TSSMCP/TRY001. After a HALT/LOAD, the new one should be running!
• If it does not run (crashes) you are back at square one: cold start...
• If the compilation has errors, the ESPOL compiler ends with a
  -DIV BY ZERO:ESPOL/DISK= 2, S= 68, A= 75
  This is intentional
• You can change the options in the card deck. Not all changes will result in a successful compile
• You might not want any physical printer to be ready during this compilation...
• The ?REMOVE PBD/= at the begin of above deck removes all outstanding print backup files (from any previous compilation.) You might want to remove that.

Howto: Using the Magnetic Drums or AUXMEM

A Magnetic Drum represents 32768 words of fast storage. It rotates at 3600 RPM and can access 256 words per revolution giving an average access time of 8 milliseconds and 16 milliseconds of transfer time for 256 words.

AUXMEM is a vast speed improvement of that, using magnetic core memory. The magnetic core can access any word within microseconds. However, it is still a mass storage device accessed through an I/O unit and the words are sequentially transmitted as 6 bit characters, so it has not the same speed as the main core memory.

Two such devices can be present. They are named DRA and DRB, regardless whether they are drums or core.

• It appears that they only get used when their status is READY when the MCP starts
• Making them READY later will not get them used
• In my emulation, they are not buffered on any permanent storage. They are cleared at each emulator start. Since they are only used for overlay, I do not expect any problems
• It is assumed, that setting the AUXMEM option (see MCP Compilation options) changes the MCP's overlay handling to use the much faster access to the core memory

When you make DRA or DRB unREADY while they have overlayd data on them, expect the following:

DRA(W) FAILURE-D18
#DRA NOT READY
DRA IOD=0100310222270535;DA=D0000600;RD=1100000200470535;RTRY=0;MIX= 2
-UNEXP IO ERR:ESPOL/DISK= 2, S= 65, A= 80
 CODE/0000000/0000000= 0 SEGS--CREATED 05/15/18 AT 11:21:52:48
 CDA REL CARD 1:ESPOL/DISK= 2
 DECK#3110 REMOVED
 MCP/STUFF13/0000000= 100 SEGS--CREATED 05/15/18 AT 11:21:54:01
 CODISK/0000000/0000000= 500 SEGS--CREATED 05/15/18 AT 11:21:55:28
 ESPOL/DISK= 2,PST= 8 DS-ED