Interestingly I've searched the web for altair programs and found nothing useful. I find that pretty amazing. Well, I've written a number of programs already using the switches, so I took a crack at my own echo program. I would have guessed the program to echo characters would be:
IN 11 011 011
021 00 010 001
OUT 11 010 011
021 00 010 001
JMP 11 000 011
0 00 000 000
00 000 000
So I keyed this in via the switches and then tried every possible configuration of windows hyperterminal I could think of, all 9600 baud, with various partty, flow control, and stop bits settings. I've tried it with and without a null modem cable.
No go.
Either my program is wrong (highly likely because I used port 021 which is for data and not port 020 which is for control). But I can't find decent descriptions of how the IO ports actually work.
I wonder if the documentation was easier to come by in 1975. Or you could just attend the local computer club group.
Paul
|