INT 21 - DoubleDOS - ADD CHARACTER TO KEYBOARD BUFFER OF CURRENT JOB            
	AH = E3h
	AL = character
Return: AL = status
	    00h successful
	    01h buffer full (128 characters)
SeeAlso: AH=E1h"DoubleDOS",AH=E2h"DoubleDOS",AH=E8h"DoubleDOS"
SeeAlso: AH=F3h"DoubleDOS"