INT E0 - REAL/32 - "L_TIMEOUT" - SET LIST DEVICE TIMEOUT
	CL = B9h
	DX = timeout value in system ticks (see #04048)
		0000h-FFEFh = new number of system ticks
		FFFDh = get current value without changing
		FFFEh = start timeout count
		FFFFh = never timeout
Return: AX = status, or current timeout value if DX=FFFDh on entry
	may destroy SI,DI
SeeAlso: INT E0/CL=BAh