The Ampro Little Board was a very simple and cheap Z80-based computer from 1984, which ran CP/M. It was, in fact, a single PCB which you could mount on the bottom of a 5.25" drive.
All about the Ampro Little Board
It stored either 400kB on a double-sided 40-track drive or 800kB on a double-sided 80 track drive. The disk format it used was a slightly quirky variation of the standard MFM IBM scheme --- sector numbering starts at 17 rather than 1 (or Acorn's 0). FluxEngine supports this.
FluxEngine has direct filesystem support for these disks, or you can pass the disk images into cpmtools:
$ cpmls -f ampdsdd ampro.img
0:
-a60014.e
amprodsk.com
bitchk.doc
bitchk.mac
cpmmac.mac
dir.com
himem.doc
himem.mac
kaydiag.lbr
kayinfo.lbr
...etc...
- Format variants:
400
: 400kB 40-track DSDD800
: 800kB 80-track DSDD
To read:
fluxengine read ampro --400 -s drive:0 -o ampro.img
fluxengine read ampro --800 -s drive:0 -o ampro.img