Bitfields for IBM/MS INT 13 Extensions API support bitmap: Bit(s) Description ) 0 extended disk access functions (AH=42h-44h,47h,48h) supported 1 removable drive controller functions (AH=45h,46h,48h,49h,INT 15/AH=52h) supported 2 enhanced disk drive (EDD) functions (AH=48h,AH=4Eh) supported extended drive parameter table is valid (see #00273,#00278) 3-15 reserved (0)