Re: Fluke 9010A Checksum Hack

"Normal" CSUM routines do indeed just ADD all the bytes of the ROM and look at the
remaining 2 bytes. You should just be able to change the instruction from XOR to ADD
assuming that they still carry over the same and look at the same 2 byte (least
significant) result. :-)

jess

"Fish, David" wrote:
>
> Hi Folks,
>
> Since there seems to be renewed interest in this project
> I might as well 'let the cat out of the bag'. I've been
> working on this project for about a month so far in my
> spare time and I'm close to completing it. I've already
> emailed Jess and John to let them know, but I don't think
> John got his email, our system went down due to the virus
> and it may not have made it out.
>
> Anyway, so far I've got the code disassembled, all the
> message and look-up tables mapped out and the I/O
> routines located. I got my emulator hooked up to a 9010A
> and it finally functional (forgot to disconnect the two
> watchdog traces). On Saturday, I located the Checksum
> routine. The 9010A seems to perform an accumulating XOR
> Checksum calculation. I'm not sure what type of calculation
> PROM programmers use but I'm guessing it's just addition.
> Any know for sure?
>
> I'll let you all know when I've got the hack completed.
>
> David Fish "We want...Information. INFORMATION
> Melrose, MA USA You won't get it!
> fishd.at.tiac.net By hook or by crook we will"
> dfish.at.bev.etn.com _The Prisoner_
>
> > -----Original Message-----
> > From: John Robertson [mailto:jrr@flippers.com]
> > Sent: Thursday, May 04, 2000 4:02 PM
> > To: TechToolsList@flippers.com; TechToolsList@flippers.com
> > Subject: Re: Fluke 9100s - Who has what?
> >
> >
> > The problem with the checksum that the Fluke generates is
> > that it has no bearing on checksums that are created by
> > most eprom programmers etc, so it means you have to create
> > a new list of "Fluke" checksums for each rom image. I have
> > sent the file of the base unit for the 9010A to Jess, but
> > it is a Z80 based system and he is not so familiar with that,
> > any Z80 guru's want a crack at this?
> >
>
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Received on Mon May 08 08:48:24 2000