INT 16 - PC Tools v5.1+ DESKTOP API - CHECK FOR AND GET KEYSTROKE
AX = FFE6h
Return: AX = 0000h if no key available
else  BIOS keycode
Notes:  available only when popped up
invokes INT 28 idle interrupt before checking for key


16FFE6 - PC Tools v5.1+ DESKTOP API - CHECK FOR AND GET KEYSTROKE