Re: ROM Editing

[mjmahon@aol.com (Michael J. Mahon)]

Paul Grammens wrote:

>"David Wilson" <david@uow.edu.au> wrote in message
>news:3c9a582d$1@news.uow.edu.au...
>> >> Paul Grammens wrote:
>> >> > Anyone have any pointers on how to hack ROM's?
>>
>> 1.Transfer contents to a disk file.
>> 2.Run it through a disassembler.
>> 3.Add comments and labels to code.
>> 4.Add new code or modify existing.
>> 5.Reassemble.
>> 6.Burn new EPROM.
>> 7.Test it.
>>
>> I did this with my first Cirtech SCSI card. It only supported up to 128MB
>> disk drives and I had a 200MB unit. I have my own disassembler I wrote
>that
>> runs on UNIX. I found how it handled 1st 4 32MB partitions and added
>similar
>> code for next 4 partitions giving total of 256MB per disk. It worked
>perfectly.
>> --
>
>Thanks for the tips, David. I've got step 1 done, and downloaded the
>disassembler. Disassemblers must be platform-specific, right? Or maybe just
>CPU-specific. Is there a better one than S-C Disassembler?
>Steps 2 thru 5 are the tough ones, I've got the others covered.

S-C Disassembler is a good one in my experience.

BTW, Bob Sander-Cederlof is the author of the AE firmware,
as well as the noted S-C Assembler and the Disassembler.
He went to work for AE after gaining considerable acclaim as
an Apple assembly language expert.

I think that several folks, myself included, would be interested
in a good disassembly of the Vulcan code.  I took a shot at it
many years ago (when my reverse-engineering skills (or maybe
my patience  ;-) were not so developed, but didn't complete it.
I do remember being impressed at the unrolled loops used for
moving data from the onboard buffer to Apple RAM.

-michael