INT 51 - Tandy 2000 - KEYBOARD SERVICES                                         
Note:	this interrupt is identical to INT 16 on Tandy 2000
SeeAlso: INT 16/AH=00h,INT 16/AH=01h,INT 16/AH=02h,INT 16/AH=04h"Tandy"
SeeAlso: INT 16/AH=04h,INT 4A"Tandy 2000",INT 4C"Tandy 2000",INT 52"Tandy 2000"