Terminate and stay resident program

In computers, a terminate and stay resident program (commonly referred to by the initialism TSR) is a computer program that uses a system call in DOS operating systems to return control of the computer to the operating system, as though the program has quit, but stays resident in computer memory so it can be reactivated by a hardware or software interrupt. This technique partially overcame DOS operating systems' limitation of executing only one program, or task, at a time. TSR is unique to DOS and not used in Windows.

Some terminate and stay resident programs were utility programs that a computer user might call up several times a day, while working in another program, using a hotkey.

^{[ PM | Exclude me | Exclude from subreddit | FAQ / Information ] Downvote to remove | v0.22}