CP/M 2 Emulator

Not all functions under CP/M 3.x are compatible to those of CP/M 2.2. Particularly direct BIOS calls may cause crashing CP/M 3.x. Also the BDOS function 27 — Return address of allocation map — may cause incorrect results. (User of TURBO-PASCAL 3.x know the problems determining the free disc space.)
Use this RSX if you are running programs making problems as described above. After installing the RSX CP/M 3.x acts like CP/M 2.2.

Here the source files:

Main program The program checks whether there is room for the RSX in the COMMON memory area and installes the RSX in case it is
RSX The RSX must be combined with the main program
Deleting program This tool deactivates the RSX