RE: Gottlieb / Q*bert scripts for the 9010A/9100

I'm coming into this thread half way so excuse me if i'm getting the wrong
end of the stick.

RomIdent does indeed use Standard CRC32, With Thierry's I wrote a VB front
end that imported the Romident database into access and then took a file
from disk or memory (It was an add on tool for my eprom programmer) and
calculated it's CRC32 and scanned the DB for matches. The one down side I
found was the diffence with how C++ and VB handle the datatype, it took a
while to realise that VB had inverted all of the CRC values.....

Chris

-----Original Message-----
From: Phillip Eaton [mailto:inbox@phillipeaton.com]
Sent: 08 May 2002 22:51
To: TechToolsList@flippers.com
Subject: RE: Gottlieb / Q*bert scripts for the 9010A/9100

AFAIK, the signature that Rom Ident uses is a standard CRC-32 calculation,
which is calculated in an identical way to CRC-16 and CCITT CRCs, using all
bits of each byte in the file.

The polynomial may be different (i.e. more bits for CRC-32), but the
technique is the same for any CRC/Signature calculation. Have a search for
CRC-16 and CRC-32 on Google, you get back loads of results.

WinZip uses CRC-32, as does MAME, to see the CRC-32 for a file, zip it up in
WinZip (8.0?) and set the configuraiton options to show the CRC. You'll see
it's 8 hex characters i.e. 32 bits.

Cheers,
Phillip Eaton

> -----Original Message-----
> From: John Robertson [mailto:jrr@flippers.com]
> Sent: 08 May 2002 22:44
> To: Phillip Eaton; TechToolsList@flippers.com
> Subject: RE: Gottlieb / Q*bert scripts for the 9010A/9100
>
>
> Home today fighting a small chest infection...
>
> I don't think these ROM Signatures generated by the base numbers are true
> "Signatures" after all. Note that the coding for them does not follow the
> convention of using HP's ACFHPU, rather the "signature" generated uses
> standard HEX nomenclature.. Now I wonder what this number
> actually is...I'm
> going to try to use my new Arium ML1400 Logic Analyzer to see if
> I can find
> the section of code in the base that actually is used to create the ROM
> signature and report back.
>
> I think it is more likely a signature similar to the one ROMIDENT uses...
> anyone know it's root formula?
>
> John :-#)#
>
> At 10:06 AM 07/05/2002 +0100, Phillip Eaton wrote:
>
> >Ah ha! You've just spotted the reason for my previous
> >question - What's the polynomial?
> >
> >I worked out the Cat Box polynomial directly from the PCB,
> >you can actually _see_ the address counter and the XOR
> >feedback points. Apparently the Cat Box polynomial is the
> >same as the HP one.
> >
> >Now it gets a bit confusing... (Especially as I've not
> >actually had time to get stuck into my Fluke and confirm all
> >of this!)
> >
> >/As far as I can see/ The Fluke creates a signature with a
> >similar procedure to a boring old checksum, by reading each
> >byte of a region of memory space and performing a calculation
> >on it to produce a single 16 bit signature. To create the
> >signature, it right shifts each bit of each byte into the
> >polynomimial XOR 'circuitry'. On the Cat Box the 'circuitry'
> >is physical, but is probably software on the 9010a for
> >reasons shown below.
> >
> >On a Fluke, there seems to be a bit of general confusion as
> >to where the calculation is done, in the pod or in the main
> >unit. I would be very surprised if it were done in the pod
> >but I could be wrong. (I hope to have a look myself in the
> >summer, when I've finished college...)
> >
> >Anyway, the Cat Box performs Signature /Analysis/, which also
> >produces a signature, but not by reading in a chunk of bytes
> >and creating a signature from them via software.
> >
> >Using a probe, it reads the chain of bits that occur at a
> >particular point on a PCB when the address bus is ramped from
> >0 to FFFFH. To test one part of a circuit e.g. a single ROM,
> >you would tie a sig analysis start and stop line to the chip
> >enable of the ROM which in effect maps to that ROMs address
> >space only.
> >
> >If you point the probe at the one data line of the ROM, you
> >will get a stream of bits which you can XOR in a similar way
> >to the standard Fluke signature. BUT the calculation will
> >only be performed on one bit of each byte as there are 8 data
> >lines and you only have one probe! Thus, you get 8 signatures
> >per ROM as shown in the Atari Cat Box signature reference for
> >each PCB.
> >
> >A Fluke signature is an improved way of testing a ROMs
> >integrity over a checksum, but it can't be used to analyse
> >anything other than a fixed areas of memory space i.e. ROM.
> >Signature /Analysis/ can test /any/ digital part of a circuit
> >as long at it derives from the processor's address and data
> >decoding (i.e you can't do the video circuitry).
> >
> >My program uses a software way of calculating the signature,
> >but it emulates the Atari probe hardware i.e. by testing only
> >1 bit of a byte and thus it is an emulator, as opposed to
> >just a signature generator.
> >
> >I originally wrote it to do the 8 bits of a ROM, but this
> >added an extra loop, and all I was really trying to do was
> >show how it worked, so I went back to just one bit for
> >clarity.
> >
> >Note BASIC has no bitwise operators so the code is a bit
> >cumbersome, if you rewrote it in C, or even better Forth, it
> >would be a fraction of the size.
> >
> >You could quite easily modify my emulation to either create
> >all 8 checksums together like the Cat Box or pass all of the
> >information from each byte serially into the calculation like
> >the Fluke (if you knew it's polynomial).
> >
> >Cheers,
> >Phillip Eaton
> >http://www.phillipeaton.com
> >
> >---- Original message ----
> > >Date: Mon, 06 May 2002 21:45:41 -0700
> > >From: John Robertson <jrr@flippers.com>
> > >Subject: RE: Gottlieb / Q*bert scripts for the 9010A/9100
> > >To: "Phillip Eaton" <inbox@phillipeaton.com>,
> ><TechToolsList@flippers.com>
> > >
> > >
> > >Hi Phillip,
> > >
> > >I just tried your emulator on a bunch of Asteroid files and
> >compared them
> > >with the signatures on the 9010 and I do not get the same
> >results... Does
> > >it not setup the same Signature that HP designed and thus
> >should it not
> > >give the same results for any file as the Fluke would do on
> >a ROM signature
> > >test? The signatures generated by your emulator are
> >consistent - identical
> > >files give identical signatures...
> > >
> > >Might I ask what the "Bit number <0 - 7>" refers to in the
> >emulator?
> > >
> > >John :-#)#
> > >
> > >At 11:08 PM 06/05/2002 +0100, Phillip Eaton wrote:
> > >
> > >
> > >>I wrote one of these a few years back. It's part of my
> >Atari Cat Box
> > >>signature analysis write-up which is held at
> > >>http://www.gamearchive.com/video/manufacturer/atari/vector/s
> >ignatures/
> > >>
> > >>It includes a very simple program source code (to aid
> >understanding) to do
> > >>what you mentioned in MS DOS QBasic for the Cat Box.
> > >>
> > >>You could quite easily use it as a base to write your own,
> >or simply change
> > >>the polynomial in mine and it'd do what you need.
> > >>
> > >>How did you work out the ploynomial?
> > >>
> > >>Cheers,
> > >>Phillip Eaton
> > >>
> > >> > -----Original Message-----
> > >> > From: owner-techtoolslist@www.flippers.com
> > >> > [mailto:owner-techtoolslist@www.flippers.com]On Behalf
> >Of John Robertson
> > >> > Sent: 06 May 2002 22:03
> > >> > To: TechToolsList@flippers.com
> > >> > Subject: Re: Gottlieb / Q*bert scripts for the 9010A/9100
> > >> >
> > >> >
> > >> >
> > >> > What we need is for some bright person to write a simple
> >utility that
> > >> > converts data files to signatures. The signature formula
> >is fairly simple
> > >> > and if combined with Bill Ung's ROMSUM would be a nice
> >tool for our
> > >> > package. If you don't know ROMSUM it is a dos utility
> >that will give a
> > >> > checksum listing plus the ROM size for a single or group
> >of files...
> > >> >
> > >> > The Signature process is a CRC process that uses the
> >following feedback
> > >> > equation: X(to the 16th) + X(to the 12th) + X(to the
> >9th) +X(to
> > >> > the 7th) +
> > >> > 1 or
> > >> > P(X) = X(15th) + X(9th) + X(7th) +X(4th) + 1
> > >> >
> > >> > So who wants to make a simple (not for me!) binary
> >program that
> > >> > allows one
> > >> > to input a file and outputs it's signature?
> > >> >
> > >> > John :-#)#
> > >> >
> > >> > At 09:11 AM 06/05/2002 -0400, Kev wrote:
> > >> >
> > >> >
> > >> >
> > >> > >Anyone written any test scripts for these or at the
> >very least have some
> > >> > >checksum signatures?
> > >> > >
> > >> > >Thanks,
> > >> > >Kev
> > >> >
> > >> >
> > >
>
>
Received on Thu May 09 01:56:49 2002