For questions related to the CP/M operating system by Gary Kildall.
The CP/M operating system (acronym for Control Program for Microcomputers) is an operating system developed by Gary Kildall at Digital Research for the 8080 microprocessor, although it can be used in Z80 environments, where it gained popularity.
For questions related to a particular implementation of CP/M, please add the relevant tag indicating the target machine. For programming for CP/M, also use the programming tag.
More information about CP/M: https://en.wikipedia.org/wiki/CP/M
Unofficial page devoted to the CP/M (with lots of information and source code): http://www.cpm.z80.de/