INT D4 - PC-MOS/386 v5.01 - GET SYSTEM CONTROL BLOCK SEGMENT/SELECTOR           
	AH = 26h
Return: DX = segment/selector of the System Control Block (see #04004)
Note:	this function supersedes AH=02h
SeeAlso: AH=02h,AH=27h,AH=28h,AH=29h,AH=2Ah