Re: Cracking the 9010A ROM signature generator

If anyone wants them I have some emulator execution trace
capture files of the IO_LEARN sequence. Somewhere within
this listing the 'calculation' is performed. The capture, IIRC,
is MANY loops within loops but I believe it's all there. The
above mentioned capture file is 125Kbytes long, there's ALOT
of information in it. There are some other trace capture files
I saved too, just say the word and thier yours.

Dave

----- Original Message -----
From: Mike Coates <mcoates@mame.net>
To: <TechToolsList@flippers.com>
Sent: Thursday, November 08, 2001 5:55 PM
Subject: Re: Cracking the 9010A ROM signature generator

> I've done some dissassembly on the code for both the pod and the base, and
> have to agree with David, whatever it was written in had an awful
> compiler! - It's not easy tracking down anything, since the code is so
> illogical!
>
> the code in the pod is a little more understandable, but only just, and
not
> understanding (yet) how the pod communicates to the UUT makes ot difficult
> to follow as well.
>
> My next step in the attack on understanding the code is to try and create
an
> emulator for the pod software, at least then I may be able to trap all of
> the reads/writes that communicate with the pod (I need to know this for a
> later project anyway!) - hopefully, seeing the data transfers may help
gain
> understanding in how the entire thing works
>
> from your examples, it certainly follows no checksum algorithm I know of,
> reversing the bit pattern either needs a lookup table (which I will check
> for in a minute) or some nasty calculations (which again, should be
> obvious!). I'm going to have another troll though the 48k of code looking
> for anything that may implement such things.
>
> just out of interest, does the 6502 pod (or another 8 bit pod) generate
the
> same checksum, and secondly, does it generate the same checksum for the
same
> data at a different address ?
>
>
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Received on Thu Nov 08 15:28:22 2001