INT 5F C - TI Professional PCIBM PC - KEYBOARD QUEUEING VECTOR
Return: all registers preserved
Desc:	hook for multitaskers to be informed when a keypress is placed in the
	  keyboard buffer
Note:	the default handler is a simple IRET instruction
SeeAlso: INT 09,INT 4A/AH=00h"TI",INT 59"TI Professional"
SeeAlso: INT 5B"TI Professional",INT 5C"TI Professional"
SeeAlso: INT 5D"TI Professional",INT 5E"TI Professional"