TS Rs
| Field | Programming |
| Went Obsolete | mid 90s |
| Made Obsolete By | Windows 95 |
| Knowledge Assumed | DOS internals (if you wanted to call int 21h) |
| When useful | DOS like systems |
TSR (terminate and stay resident) was a technique that allowed computer programs of the DOS era to be loaded into memory and be used later when some other DOS program was used. The typical TSR would take over some interrupt (e.g. keyboard) and perform its action (e.g. grab the screen and save it to some file) when an interrupt call met some predefined condition.
See also Editing AUTOEXEC-BAT and CONFIG-SYS to get as close as possible to 640K of free memory
