642B UPAK

[Richard Carlson]

Hello Steve,

Hope you are doing well.

I was working on my 642B emulator/simulator, and I wanted to start using the UPAK memory file that you provided me for testing my UNIVAC 1540 tape sim. However, when I disassembled the program, I noticed that there are some references (subroutine calls and variables) outside of the current address space of the program, which ends at 02046. I also noted that there are some RJPs that point to the middle of code blocks, and not normal entrance cells. Do you happen to have the original source code?

Thanks!

Rich C 

[sboy...@gmail.com]

Rich;

That attached archive contains all of the files that I have for the 642 UPAC program. I got these originally from Duane Craps. He can be found on MeWe. He is probably more knowledgeable about this program that I am.

Steve

[Duane Craps]

Hi All

I only have the a Paper Tape

I did not expect there to be more than one block on the tape Turns out there are 5

1.) 622-2044

2-5) each 2000 - 2044

Looks like it is to be written to Mag tape and different functions call in different overlays. The basic Load has a function to write the UPAC to the tape.

Oh the contortions they went to when memory was limited

The  .76  file is an ASCII image of the Paper Tape The header for bi-octal tape is 76 octal. the first non-zero frame is 62 decimal or 76 octal.

I never got into it far enough to determine what the peripheral devices are.

Duane

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[Richard Carlson]

Thanks guys! I will review.

[Richard Carlson]

I have decompiled, and analyzed the code, including all other the segments/blocks. It appears that there are only 4 channels, that are used in the UPAK program.
These are 6, 7, 13, and 14. 

The base program, (623-2044), I am calling Block 1, uses channel 13, and channel 7.

Block 2 (2000-2477), uses channel 6, and channel 14.
Block 3 (2000-2477), uses channel 6.
Block 4 (2000-2477), uses channel 6.
Block 5 (2000-2477), uses channel 13.

I have not found any details on what should be attached to what channel. I can only assume that there is a Magtape channel, probably attached to channel 13. Channel 7, couold be the Teletype. Channel 6 might be the papertape/teletype unit (1532?) Haven't a clue about channel 14, without digging deeper into the EF words, I am hoping that either of you, happen to know what goes where. 
Thanks!

[Duane Craps]

Richard,

Assuming that the attached card is the correct one:

The card calls them base and 1-4

Since the base program can copy the Paper Tape to Mag Tape. It should be MT an 13 and PT on 7

TTY an channel 6

There is a note on the card that boot loading with key  3 set will cause it to wait for input from the SMP so that would be the channel 14

Duane

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[Richard Carlson]

So, what specifically, determines what segment 1-4 (2000-2477), gets loaded as an overlay, over the basic program's addresses 2000-2044?
Do you need to set some additional parameter in one of the registers, or does it do it automatically, by the values placed in Q and A only?

[Duane Craps]

Richard,

My experience with the 642s was limited to helping to running  test during ship yard periods.  I was the S/Y 1219 guy and spent most of my time in missile plot. Mike (ex UNIVAC) sent me some 1219 Paper Tapes and must have included the 642B UPAK by accident.

I found the Instruction card on the UNIVAC VIP site.

There is a note on the card about starting all functions at P=00001. Maybe UPAK puts srartup code down thereas part of fault recovery. Or maybe it refers to base+1

Mike,

You got any brain cells left? If you still have 642B stuff Richard could use help on his emulator program.

DC

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