Eric J. Rothfus wrote:
Anyone out there know the details of nibblizing for the very early Apple 5x3 GCR? There's a description in "Beneath Apple Dos" (BAD) but it is rather weak, and not very precise. I'm looking for the details of the nibblizing process that separate the bits from the target 256 bytes into the 410 "bytes" that will then be mapped to GCR5x3.
Well, if anyone has a copy of 13-sector DOS 3.2 kicking around, then we could disassemble it and answer your question. I'm willing to disassemble it and post it here, but I don't have a copy of DOS 3.2 anywhere.
Does anyone have an old 13-sector Disk II controller card ROM? The boot code on there would also give the secret away. Again, this may be hard to find, but the code is shorter than DOS 3.2 RWTS so it would be quicker.
-- Jerry Penner e-mail: awanderin at yahoo dot ca