- CP/M is a single tasking operating system and having grown-up with single tasking systems this has never really been a problem for me. There is style of program that would make my life easier, however. When I was in college, using MS-DOS, we used a program called Borland Sidekick. This is a TSR that stayed in memory and when you pressed a hot key combination the program would display on the screen. Sidekick was great because it would allow you to run a program from the DOS prompt and then if in the middle of this program you wanted to edit a document or check the ASCII table, you could press the correct keys and it would suspend your executing program and start Sidekick.