INT 13 - HARD DISK - READ SECTOR BUFFER (XTIBM PC XT only)
	AH = 0Eh
	DL = drive number (80h = first, 81h = second hard disk)
	ES:BX -> buffer
Return: CF set on error
	CF clear if successful
	AH = status code (see #00234)
Notes:	transfers controller's sector buffer.  No data is read from the drive
	used for diagnostics only on PS/2IBM PS/2, any model systems
SeeAlso: AH=0Ah