Firmware Release Notes

This document details all firmware changes made to the DM-xx24 series drive.  At the
time of this document, interim firmware revision 1.1d is the latest change.   
                                        Changes
                                        Affected
       
       1.03 9/3/92     Auto speed reduction change at read 
                       error detection.  Auto switch operable 
                       without performing a device reset.  
                       Change Definition parameter altered to 
                       support speed change.  Mode sense page 
                       code 2 and E supposedly fixed. SCSI xfer
                       timeout reset added.
       
       1.04            Fixed minor SCSI Interrupt Handling.
       
       1.05 10/27/92    Fixed Selection anomaly.  Incorporated automatic low speed
                        to high speed switching.  Modified calculation 
                        of Lead-Out address for increased efficiency.  Fixed Read 
                        Header command anomaly. 
        
        1.06 11/18/92   Allowed drive to properly negotiate Synchronous 
                        Transfer.  Fixed a minor problem with data block size transfers smaller
                        than 2048 bytes.  Modified Spindle motor braking algorithm
                        to increase reliability during seek operations.
        
        1.08  1/26/93   This change incorporated many fixes and enhancements
                        including:
                        - Photo CD-Multi-Session Support.
                        - Limited support for Connect/Disconnect.
                        - Decreased processor initialization time.
                        - Allowed disc to recognize up to 99 audio tracks.
                        - Returned good status (pacified) for a prevent/allow media  
                          removal command.
                        - Support Read Extended (28h) with transfer length = 0.
                        - Support to play first frame of first audio track.
                        - Increased reliability of LASER optics power management.
                        - Support for Linked Command and Relative Addressing***
                        - SCSI reset detection.
                        - 1 block disconnect/reconnect temporary fix.
                        - Pre-fetch support.
                                         
        1.09   2/8/93   Delayed processor initialization so that drive system 
                        power could settle first.  This version fixed initial problem caused
                        by version 1.08.

        1.10   4/28/93  Again several fixes:
                        - Fixed mis-calculation of sub channel MSF data.
                        - Fixed Mode Select Page Code E. 
                        - Corrected Read Sub Channel to indicate correct audio        
                          status of 'No Audio Status to Report' vice 'Audio Paused'.
                        - Fixed anomaly with Connect/Disconnect.
                        - Fixed problem with Arbitration
                        - Support for SCSI Abort command
                        - Corrected Pointer Messages


Developer Application Notes
All firmware revisions below 1.1 need to use the Audio Control command (C9h) instead of the SCSI-2 
Mode Select/Sense Page Code (0Eh).  The Page Code (0Eh) in the previous firmware releases did not
work reliably.  This bulletin applies only for DOS specific drivers only.  Owners of multi-tasking
operating systems (OS/2, NT, UNIX, etc.,) should upgrade to firmware 1.1.  This latest firmware version
takes care of possible drive malfunction during large file transfers.  Therefore, full implementation of
Page Code E can be included without concern of previous firmware levels.

Note Concerning Firmware Revision 1.1
The 1.1 firmware originally was intended for interim use only.  However, progress to iron out remaining
issues with this version were never completed.  Therefore, some minor problems exist with 1.1 that
should be mentioned.

1.      During a SCSI reset, the drive issues two Unit Attentions instead of one.  In most cases
        this is no problem.  However, using a Future Domain controller under OS/2 2.1, the
        drive will not be recognized.

2.      If media is placed inside the drive prior to DOS bootup,  the drive may not initialize
        properly.  Therefore, remove the media from the drive prior to boot up. 

3.      During large file transfers the drive may reset itself.  This only happens under OS/2 and
        only in very isolated circumstances.  The error is recoverable and shall not cause the
        system to fail.  
               
