TO: JOHN LOHMEYER                                        X3T9.2/88-081 R0

  FROM: BILL SPENCE

  DATE: JULY 12, 1988

  RE: LOG SELECT/LOG SENSE PAGES


             Table x.y:  Page Codes for LOG SELECT/LOG SENSE Commands

==============================================================================
Page Code   Description                                   Section
----------  --------------------------------------------  -------
 00h        Summary List of Supported Pages
 01h        Buffer Overrun/Underrun Counter
 02h        Write Error Counter
 03h        Read Error Counter
 04h        Read Reverse Error Counter
 05h        Non-Media Related Event Counter
 06h        Last n Error/Event Log
 07h - 1Fh  Reserved
 20h - 3Eh  Vendor Unique
 3Fh        Reserved
==============================================================================



                 Table x.y:  Buffer Overrun/Underrun Counter Page

==============================================================================
  Bit|   7    |   6    |   5    |   4    |   3    |   2    |   1    |   0    | 
Byte |        |        |        |        |        |        |        |        |
==============================================================================
 0   |                           Page Code (01h)                             | 
-----|-----------------------------------------------------------------------|
 1   |                           Reserved                                    |
-----|-----------------------------------------------------------------------|
 2   | (MSB)                                                                 |
-----|---                        Page Parameter Length                    ---|
 3   |                                                                 (LSB) |
-----|-----------------------------------------------------------------------|
 4   | (MSB)                                                                 |
- - -|- -                        Parameter Code                           - -|
 5   |                                                                 (LSB) |
-----|-----------------------------------------------------------------------|
 6   |                           Parameter Contol Byte                       | 
-----|-----------------------------------------------------------------------|
 7   |                           Parameter Length (n)                        |
-----|-----------------------------------------------------------------------|
 8   |                                                                       |
- - -|- -                        Counter Value                            - -|
7+n  |                                                                       |
==============================================================================





  The parameters  for this page comprise only counters.  The list of parameter 
codes is given in Table _._.


           Table x.y:  Parameter Codes for Buffer Overrun/Underrun Page

==============================================================================
Parameter   Description                                   Section
----------  --------------------------------------------  -------
 00h        Undefined
 01h        Undefined
 02h        SCSI bus busy - underrun
 03h        SCSI bus busy - overrun
 04h        Transfer rate to slow - underrun
 05h        Transfer rate to fast - overrun
 06h - 7Fh  Reserved
 80h - FFh  Vendor Unique
==============================================================================