digital equipment corporation · maynard, massachusetts
PDP-8 (Straight 8) Diagnostics

This document listed MAINDEC-801, MAINDEC-08-D01A, D02B, D04B, D05B, D07B, D1MA, D1L0, D2EP, D2QD, D1AC as the diagnostics to run on a straight 8 and gave partial instructions for running them. The D2EP diagnostic listed should have been D2PE. The document also listed EAE test MAINDEC-08-D0BA which I haven't been able to find. I did find a D0AA EAE MAINDEC. The maintenance manual listed the older MAINDEC-8## series for which no instructions for operation seem to be available.

md-801-1.rm            - Inst test 1 RIM format, Start 200 will halt at 200, set SR 7777, cont, 
                         will halt at 202 with AC=SR, cont, will halt at 205 AC=0, cont
maindec-801-2a.bin     - Inst test 2A Start 1200 SR 7777.  Will stop with AC 0 at HLT at 1202, hit continue (no instr)
md-801-2b.bn           - Didn't figure out how to run (no instr)
maindec-801-2C.bin     - Inst test 2C Start 41 SR 0. NO TTY (no instr)
maindec-08-d01a-b-pb   - Inst test 2A Start 1200 SR 7777.  Will stop with AC 0 at HLT at 1202, hit continue
maindec-08-d02b-pb.bin - Inst test 2B start 200 SR 1600
maindec-08-d04b-pb.bin - Inst test rand jmp start 200 SR 0000
maindec-08-d05b-pb.bin - Inst test rand jmp-jms start 200 SR 0000
maindec-08-d07b-pb.bin - Inst test rand isz start 37 SR 0 first run, SR 1 second run
maindec-08-d0aa-pb.bin  - Inst test 3A EAE (no instr) start 0201 SR 1000 print, 4000 halt
                         (200 start for later machines with SCL instruction)
maindec-08-d1b1-pm.bin - Mem address low, RIM format, start 4
maindec-08-d1b2-pm.bin - Mem address high, RIM format, start 7400
maindec-08-d1l1-pm.bin - Mem checkerboard low, RIM format start 5 SR 0100 no TTY
maindec-08-d1l2-pm.bin - Mem checkerboard high, RIM format start 7430 SR 0100 no TTY
maindec-08-d1ma-pm1.bin- Mem address, Start 4 SR 0, restart 0 (prints 11, identical to d1b1 except tape format)
maindec-08-d2pe-pb.bin - ASR 33/35 Teletype tests part 1, operation too complex to summarize
maindec-08-d2qd-pb.bin - ASR 33/35 Teletype tests part 2, operation too complex to summarize
maindec-08-d1ac-pb.bin - Memory power on/off test, start 14, halt 42, start 1, power off and on, start 1 NO TTY

maindec-d01a-pb.bin is PDP-8 paper tapes that doesn't match the other

"No TTY" indicates the diagnostic does not send anything to the teletype 
interface. Those diagnostics halt on error. The others the given switch
settings if I could find them have it print on error but not halt. Some
such as d01a halt without printing. It only prints 2A at the end of each pass.

"No instr" indicates I haven't found any instructions. The start address and
switch register setting are a guess from disassembling the tape and possibly
later versions of the test.

A maindec-08-d0ba should exist as second half of EAE testing but I have
not found a copy.  I haven't gotten d05b not running
I found a maindec-08-d01c-pb.bin, start 144 SR 0, halts 146 AC 0 which is not
compatible with straight 8. It tests IAC with rotate which doesn't work on
a straight 8.

My MAINDEC and other paper tapes images are available here. More MAINDEC's are available here. Instructions for operations are available here and searchable here.

I have some of the original maindec-801 etc series and more are available at PDP8/S diagnostics but I haven't found any information on running them. From my 1973 diagnostics manual all except the maindec-801 seem to have been superseded by the maindec-08 versions.

If you can't find something email me.

Up to straight 8 restoration

Feel free to contact me, David Gesswein djg@pdp8online.com with any questions, comments on the web site, or if you have related equipment, documentation, software etc. you are willing to part with.  I am interested in anything PDP-8 related, computers, peripherals used with them, DEC or third party, or documentation. 

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