CP/M 3 (CP/M Plus)

Memotech computer disk systems were based on the CP/M 2.2 operating system, as are all of the modern day Memotech removable storage systems, including REMEMORizer, CFX and the original release of MFX.

Digital Research released a later version of CP/M as CP/M 3, also referred to as CP/M Plus. Quoting from the CP/M Plus Operating Guide, "CP/M(R) 3, also marketed as CP/M Plus(R) , is a single-console operating system for 8-bit machines that use an Intel(R) 8080, 8085, or Zilog(R) Z80(R) CPU. CP/M 3 is upward-compatible with its predecessor, CP/M 2, and offers more features and higher performance than CP/M 2."

For most users, CP/M 3 offers very few benefits over a CP/M 2 system, but the most significant are support for additional memory through bank switching and support from file time/date stamps with support for a Real Time Clock. The larger memory available (512kB) and the option to install a Real Time Clock in MFX meant that there was some incentive to port CP/M 3 to MFX.

Martin has (almost) gotten CP/M 3 running on MFX. The "disk" geometry is considerably different to CP/M 2.2, so the Memotech SDX ROM cannot access the disk from BASIC, but the the CP/M mode works well and can coexist with the CP/M 2.2 system on the same media with separate boot options for the two systems. Further details will be available from the MFX pages shortly.

	Title	Publisher	Source
	CP/M Plus (CP/M Version 3.0) Operating System System Guide		cpm.z80.de