RichCini
Veteran Member
All --
I'm currently working on a project that's tangentially related to TOPS-10/PDP-10 that I need some help in deciphering. With the impending 40th anniversary of the PC, I started investigating one very small part of it, a program called "20HAL" which is a PC-based program used between Microsoft and IBM to exchange files during the development. Of course, it's undocumented, but I have done a disassembly and have a few questions about how a link between Microsoft's PDP-10 and IBM in Boca Raton might have been designed. It's not clear if this program was used on one end or both ends (although I can't imagine IBM having a PDP-10).
As I disassembled the code, I noticed two character strings that are sent back-to-back: ^C^CPJ followed by TTY FILL 3. The first looks like it breaks into the TOPS-10 monitor (although I don't know what "PJ" is; maybe a shortcut for "PJOB") and the second is an identifiable TOPS-10 command. According to some other research, Microsoft stored the code being developed on its PDP-10 which was then downloaded to a test machine for assembly.
What I envision is that whatever machine was running this program (which, by the way, looks like a translated CP/M program) was connected to the pass through serial connector on a terminal (or directly to a front-end processor of some sort) otherwise it would have no need to send TOPS-10 commands. I did look at the Decsystem-10 Data Communications Guide for Software Specialists, so I have a general idea, but would someone at the time have used a leased line between the sites? Modem dial-up of some sort (either direct or through Tymnet)? There are no obvious modem commands or phone numbers in the code, nor any other TOPS-10 commands.
So, the question is two-fold. How would a setup like this have been designed and what is the "PJ" command? Is the scenario I describe plausible?
Thanks!
Rich
I'm currently working on a project that's tangentially related to TOPS-10/PDP-10 that I need some help in deciphering. With the impending 40th anniversary of the PC, I started investigating one very small part of it, a program called "20HAL" which is a PC-based program used between Microsoft and IBM to exchange files during the development. Of course, it's undocumented, but I have done a disassembly and have a few questions about how a link between Microsoft's PDP-10 and IBM in Boca Raton might have been designed. It's not clear if this program was used on one end or both ends (although I can't imagine IBM having a PDP-10).
As I disassembled the code, I noticed two character strings that are sent back-to-back: ^C^CPJ followed by TTY FILL 3. The first looks like it breaks into the TOPS-10 monitor (although I don't know what "PJ" is; maybe a shortcut for "PJOB") and the second is an identifiable TOPS-10 command. According to some other research, Microsoft stored the code being developed on its PDP-10 which was then downloaded to a test machine for assembly.
What I envision is that whatever machine was running this program (which, by the way, looks like a translated CP/M program) was connected to the pass through serial connector on a terminal (or directly to a front-end processor of some sort) otherwise it would have no need to send TOPS-10 commands. I did look at the Decsystem-10 Data Communications Guide for Software Specialists, so I have a general idea, but would someone at the time have used a leased line between the sites? Modem dial-up of some sort (either direct or through Tymnet)? There are no obvious modem commands or phone numbers in the code, nor any other TOPS-10 commands.
So, the question is two-fold. How would a setup like this have been designed and what is the "PJ" command? Is the scenario I describe plausible?
Thanks!
Rich