I am trying to understand the disk layout for a NCR Deskmate CP/M system
https://oldcomputers.dyndns.org/public/pub/rechner/ncr/dmv/manuals/ncr_dmv_s... Manual page 3-3. Decision Mate V "the formatting facility designates the surface 1 tracks with the track numbers 40 through 79." That suggests (but doesn't require) that files proceed from surface 0 track whatever, track whatever+1, ...., 39, surface 1 track 40, 41, ... 79. But how it's formatted may not correspond to the "logical order". Earlier in the document, Boot, BIOS, CCP and BDOS are on the disk side 0 and the first 3 track. The "acid test" would be to find CP/M-80 asm.com on the NCR disk and walk through sectors to see where it lives. I assume you can read hex codes. If you obtain a known asm.com binary elsewhere (pretty common) as a single file, you can pace yourself through that known binary, to find the corresponding unknown binary on the NCR diskette. if asm.com on the NCR disk is the earliest file, then it ought to start after the end of the directory sectors. Of course, it may not. http://www.cpm.z80.de/download/bootdmv.zip Is this where you found the disk image? Regards Herb -- Herbert R. Johnson, New Jersey USA https://www.retrotechnology.com OR .net preserve, recover, restore 1970's computing email: hjohnson AT retrotechnology DOT com or try later herbjohnson AT comcast DOT net