Function 0Eh	Read Sector Buffer			   (XT, Portable PS/2)
entry   AH      0Eh  
	AL      number of sectors 
	CH      cylinder (bits 8,9 in top two bits of CL) 
	CL      sector number 
	DH      head number 
	DL      drive number 
	ES:BX   pointer to buffer 
return  CF      set on error 
		AH      status code (see above) 
	AL      number of sectors actually transferred     
note 1) Transfers controller's sector buffer.  No data is read from the drive 
     2) Used for diagnostics only on PS/2 systems