See the following topics for more information: INT 20 Program terminate INT 21 DOS Function Dispatcher INT 22 Program Terminate INT 23 Ctl-break exit address INT 24 Critical error handler address INT 25 Absolute disk read INT 26 Absolute disk write INT 27 Terminate but stay resident INT 28 DOS idle loop/scheduler (undocumented) INT 29 Fast character output (undocumented) INT 2E Execute command using base level COMMAND.COM (undoc.) INT 2F Multiplex interrupt (DOS 3.x+)