Victor/Sirius 9000 had the least compatible MS-DOS disk format.
Micromint/Ciarcia used a serial terminal. Very little commercial software
could work with that.
Toshiba T300 (with 96 tpi) had CGA at B000h segment, but it was trivial to
patch PC-Write for that. Ended up loaning one of those to Toshiba's MRI
division.