**********  NOTICE:  This code is not for novices!!! **********
																																																																June 7, 1992

						This is the document file for the following microcode (aka firmware)
      and BIOS code:

           BS6MCODE.HEX       :microcode
           BS6BIOS.HEX        :BIOS code

      The code is for the AHA-1540B or AHA-1542B.  It may or may not differ
      from the code that was shipped with your AHA-1540B/1542B.
      The code is in a binary format.  The code must be programmed into a
      27C128 EPROM using a PROM programmer.  The code is 4000h bytes in size.
						A 27128A EPROM can also be used.

      The microcode and BIOS EPROMs are socketed on the AHA-1540B/1542B.
      The microcode EPROM is labeled with the word 'MCODE', and is at
      silkscreen position U12 on the host adapter.  The BIOS EPROM is 
      labeled BIOS, and is at silkscreen position U13 on the host adapter.
      The microcode and BIOS should only be changed together.	Be sure to 
      watch pin 1 orientation of the EPROM, signified by a notch on the 
      EPROM and the EPROM socket.

      This code has the following capabilities:

        -support for Western Digital and IBM SCSI drives
        -ability to access all capacity with drives greater than 1 gigabyte
         under MS DOS 5.0. (using an alternate translation scheme).  A   
         jumper must be installed on the AHA-1540/42B at J6, position 2 to
         enable the new translation scheme.  Please read the enclosed file
         154X_GIG.DOC for complete details and limitations.  A new 
         ASPI4DOS.SYS (version 3.0a) is required and is available as a free
         upgrade on the Adaptec BBS using the program UPGRADE.EXE in the
         UPGRADE file library.

      This code is provided with no warranties expressed or implied.  It may 
						or may	not improve performance/compatibility with your SCSI host
      adapter. Also, keep in mind that changing the microcode or BIOS EPROMs
      voids your warranty.