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Category: DOS kernel

INT 25 - DOS 3.31+ - ABSOLUTE DISK READ (32M-2047M hard-disk partition)

	AL = drive number (0=A, 1=B, etc)
	DS:BX -> disk read packet (see #02548)
Return: CF clear if successful
	CF set on error
	    AH = status (see #02547)
	    AL = error code (same as passed to INT 24 in DI)
	    AX = 0207h for FAT32 drive -- use INT 21/AX=7305h
	may destroy all other registers except segment registers; Win9X always
	  sets SI to 0000h due to an apparent coding bug
Notes:	partition is potentially >32M (and requires this form of the call) if
	  bit 1 of the device attribute word in the device driver is set
	original flags are left on stack, and must be removed by caller
	this call bypasses the DOS filesystem
	for FAT32 drives (which may be up to 2TB in size), use INT 21/AX=7305h
SeeAlso: INT 13/AH=02h,INT 25,INT 26/CX=FFFFh,INT 21/AX=7305h

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  Copyright 2000   by Ralf Brown     Updated Jul 2000