To: John Lohmeyer &                                        X3T9.2/93-028 rev 0
    SCSI Reflector

From: Joseph Chen
      Cirrus Logic

Date: Feb. 12, 1993

Subject: ATA 3.3 Concerns:



There is question in the ATA specification revision 3.3.  In the protocol 
overview, section 10.1.1 PIO read command, it describes the sequence of a 
read command.  The sequence is correct except the last data transfer block,
there are some discriptions missing.  

First, after the last data transfer, both BSY and DRQ should be 0. 

Second, a status read after the last sector is recommanded for the
BIOS/driver implementation.  This status read serves the purpose of 
confirming the last block of data transfer does not have error.

This recommandation adds the provision for BIOS implementors to validate 
the last block of data transfer.  The last transfer can have errors such 
as buffer underrun/overrun, parity error, and so on.  With this suggestion, 
BIOS would be able to resolve the error on the last sector.