INT 15 - SYSTEM - ENABLE/DISABLE WATCHDOG TIMEOUT (PS50+IBM PS/2 Models 50,60,70,80)
	AH = C3h
	AL = function
	    00h disable PS/2IBM PS/2, any model watchdog timer
	    01h enable PS/2IBM PS/2, any model watchdog timer
		BX = timer counter (0001h-00FFh)
	    02h disable Gearbox system
	    03h enable Gearbox system
Return: CF set on error
	CF clear if successful
Note:	the watchdog timer generates an NMIsee Non-Maskable Interrupt
SeeAlso: INT 21/AH=2Bh/CX=6269h"WDTSR"