Microelectronics | Adaptec AHA-1542CP SCSI Controller ROM BIOS Language


This Adaptec AHA-1542CP SCSI Controller has a German ROM BIOS. While I can use it because I know where and what to change to suit my needs (by comparing to my other Adaptec AHA-1542CF SCSI Controller), it would've been very nice to see the information presented in a language that I actually understand.


Translating strings inside the ROM dump itself is possible but too cumbersome (possibly involving offset manipulations). Naturally I began searching for ROM dumps on the Internet. It is amazing what sort of weird sh*t you can find on the Web these days -- count my content in as well. So I found this site called ROM Images for Various IBM PC Family Devices that stores all kind of ROM dumps. Between them, I found the AHA-1542CP dump(s). Somebody was kind enough to dump both ROMs. So there are two files, the Microcode dump and the ROM BIOS dump. The Microcode is most probably used by the Z80 microprocessor for card control purposes. So not very interesting for my needs. The other one, tagged 908501-00 D BIOS A91E is actually what I was looking for.

The rest is simple. I programmed an UV erasable EPROM chip of type 27C256-12 made by Texas Instruments, with the TL866II Plus Universal Programmer. Then I replaced IC designated U7 with this EPROM. Alles gut dann! Oh, pardon my German. All good then!

As a side note, for optical (cosmetic) reasons, I have also replaced the Microcode ROM with an UV erasable EPROM. These ICs look cool enough to actually worth the effort of reading the Microcode ROM and writing it back into the UV erasable EPROM.


... and after.

That was a quick essay offering me almost instant gratification.

This controller can now go back into my vintage DIY computer.

Your Help Matters

This essay is provided as-is and is not for commercial purposes. It reflects my experiments and research and should be treated as such. I release my work to the public for educational purposes. I did all this on my expense and in my free time. So if you like my work, or find it useful or inspiring for your projects, please consider a donation.

Copyright © 2004- Alexandru Groza
All rights reserved.
VER. 1.0 | REV. A