CP/M floppy disk formatting & test utility
The original "Bigboad" contained an WD1771 floppy controller chip onboard. It only supported "single density" mode limiting the floppy capacity to around 120kB.
Somewhere I found Information about the WD1791 which supported "double density" mode. I got hold of one of these precious chips (and the corresponsing "data separator") and built a little daugherboard which could be inserted in place of the original WD1771.
But I needed to format floppies befor I could use them, so I built a standalone formatting program (written in the assembler described above). It supported various densities, sector sizes (128, 256, 512 bytes) and interleave factors.
It was a bit cumbersome to edit/assemble the program on the HP3000 system and download the hex file into the Bigboard's memory. Later I burned 2716 EPROMs to be able to format floppies "standalone".
This activity taught me a lot about low level organization of disks.
Some files saved from this activities:
BIOS, Low level I/O, Bigboard Monitor
Floppy Formatting for WD1791 and BIOS
Pascal Compiler for CP/M
Pascal MT Plus Compiler for CP/M
Various CP/M Utilities