92198A/MCO00701A EPROM dumps wanted

[brouhaha]

Thanks to Paul providing a dump of the firmware, I have partially reverse-engineered the MC00701A/92198A firmware, and put my work in progress on github. I have identified some but not all of the character processing and HP-IL state machines. There are four more HP-IL state machines yet to be identified, and three of them are likely to be R, AH, and SH.

I'd forgotten just how unpleasant the 8048 family is if you need more than 2KB of code.

Interestingly, internally it stores 82 bytes per line, rather than 80. I haven't yet found any reason for this. It sets the CRTC for linear addressing, and uses a table to do a multiply by 82 to get the base address for each display line. Oddly enough, there are 50 entries rather than only 48. Perhaps early in development it was going to have a 25x80 display rather than 24x80.

github does a poor job of displaying files containing horizontal tab characters. Perhaps I'll replace all the tabs with spaces.

The makefile verifies that the binary file generated by the assembler has the same SHA256 hash as the original firmware.