Partition Types

[EtchedPixels]

Your docs talk about partition type 7F and the fact there is no CP/M partition geometry on the disk. It was more used post 8080 CP/M but there is a standard partition type and behaviour for CP/M syystems with a PC partition table.

0xDB is a CP/M partition with attached info, and sector 4 of the partition contains the BPB. a bad block and spare list and the drive geometry information.

https://www.seasip.info/Cpm/cpm86form.html

Still doesn't help with the compatibility issues very much but there were reasons MSX went CP/M clone with FAT file system and DRI did the same with TOS and DR-DOS.