>It's a Z80 in a cartridge and was capable of booting CP/M 2.2. But don't get too excited: the 1541 was still the 1541, so it could only run software that had been copied to a GCR disk (no directly reading MFM floppies).
This by itself is no great obstacle; even aside from the nonstandardization of CP/M 5.25" disk formats, CP/M on Apple II has the same GCR/MFM issue but the SoftCard and its many clones were among the most popular accessories, and consequently no shortage of software available on the Apple II disk format.
No, the issue with the C64 CP/M cartridge is that it sucked, like almost everything else Commodore designed. Even assuming that someone in 1985 or 1986 wanted to run Turbo Pascal or WordStar on the 128 as opposed to buying an inexpensive PC clone or a used Kaypro or Osborne, the 128 implementation is so slow that it is more or less unusable for regular use.
This by itself is no great obstacle; even aside from the nonstandardization of CP/M 5.25" disk formats, CP/M on Apple II has the same GCR/MFM issue but the SoftCard and its many clones were among the most popular accessories, and consequently no shortage of software available on the Apple II disk format.
No, the issue with the C64 CP/M cartridge is that it sucked, like almost everything else Commodore designed. Even assuming that someone in 1985 or 1986 wanted to run Turbo Pascal or WordStar on the 128 as opposed to buying an inexpensive PC clone or a used Kaypro or Osborne, the 128 implementation is so slow that it is more or less unusable for regular use.