"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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