51 INT 51 - IRQ1 relocated by DESQview
51 INT 51 - IRQ1 relocated by IBM 3278 emulation control program
51 INT 51 - IRQ1 relocated by OS/2 v1.x
51 INT 51 - TI Professional PC - RESTART TIMING EVENT
51 INT 51 - Tandy 2000 - KEYBOARD SERVICES