INT 21 - DOS 1+ - SET DISK TRANSFER AREA ADDRESS                                
	AH = 1Ah
	DS:DX -> Disk Transfer Area (DTAsee Disk Transfer Address)
Notes:	the DTAsee Disk Transfer Address is set to PSPsee Program Segment Prefix:0080h when a program is started
	under the FlashTek X-32 DOS extender, the pointer is in DS:EDX
SeeAlso: AH=11h,AH=12h,AH=2Fh,AH=4Eh,AH=4Fh