[Simh] IBM System/32 emulator

[Henk Stegeman]

Hi Al,

> Have you been able to successfully extract the microcode records from a
S/32 IPL or diagnostic floppy?

> I noticed that the first track is very different, with very long sectors
compared to the
> rest of the disk.

Yes !

Track 0 is indeed a very special sector. It starts with some sync bits
followed by a AM marker and then 2048 words including a CRC.
This sector can not be read by any standard floppy controller.
I connected a data separator to a 8" floppy drive, then I over sampled the
output with a logic analyser.
The output was saved as an CSV file.

I wrote a special programs that reads this csv file. It looks for the AM
marker (some clock pulses are missing) and then reads the 2048 words.
Last but not least I verified the CRC with a software routine. Initially it
failed, but after including the AM in the CRC is was ok.

Do you have by any chance the listings of these micro-instructions ? So far
I know they where part of the systems CE manuals.

Regards Henk