3" disks from other machines

[ASiC]

Slightly (?) off topic:Years ago, when I jumped back on the cpc, I was in a similar situation; A couple of non-readable disks and no software to format them.
I used an emulator to run discology and covert a copying/format utility to tape and saved it on a CDT file.Then I convert the CDT to wav and connect the speaker-out of the pc to the tape-in of the cpc.
Worked like a charm