INT D4 - PC-MOS/386 v5.01 - GET/SET TIME SLICE                                  
	AH = 1Bh
	AL = subfunction (00h read, 01h set, 02h get and set)
	BX = task ID (FFFFh for current task) (see AH=19h)
	CL = new time slice value
Return: CF clear if successful
	    CL = current time slice value
	CF set on error
	    AX = error code (see #01680 at INT 21/AH=59h/BX=0000h)
SeeAlso: AH=1Ah,AH=1Ch