Re: Fluke Signatures....

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I have found a nice CRC web site that allows one to change many of the
settings of the CRC to try out various polynomials.

http://www.gpfn.sk.ca/~rhg/csc8550s02/crc.html

I've been tossing in a few numbers at random to see if I can see what
variation of the CRC-16 polynomial it is. I believe that Fluke used the
standard CRC-16 formula with a preset CRC value as there is mention in the
docs about dividing the data into a fixed number. Now to figure out the
number... I'm just using an old posting of mine where I tried some two byte
data chunks on the Fluke ROM Signature generator...but I'm not getting very
far yet.

I don't know how to solve hexadecimal polynomial problems...considering
that we pretty much know the formula X16 + X15 + X2 + 1, and the data and
the result, but the mystery "binary number" is the tricky bit ... I'm way
too rusty (like 30 years since I last did this) to figure this one out
without a bit of help...

Sig. - DATA (two bytes)
93D0 - FF 00
9351 - FF 01
9390 - FF 02
9311 - FF 03
.....
93AF - FF FE
932E - FF FF

John :-#)#

At 10:45 PM 12/10/2002 -0700, John Robertson wrote:

>Seed file? I used the Pacman 6E as I recall. Just ran the calculator
>utility included with Hexedit (http://www.expertcomsoft.com/) a nice
>windows file editor - search and replace etc...
>
>There was mention that the signature was created using "The ROM signature
>is obtained by successively dividing the data in ROM by a binary number"
>in the manual as you may recall...what order would the data be divided?
>Would this matter?
>
>John :-#)#
>
>At 11:38 PM 12/10/2002 -0400, Kev wrote:
>
>>Ah yes but what are you using for a seed file for the CRC 16 /32
>>calculators?
>>
>>I belive the Fluke version is possibly based on some of the original
>>articles that were in BYTE circa 1983. I'll need to research that a bit
>>more.
>>
>>Kev
>>
>>
>>
>> >Still looking for this one - what is the algorithm used to generate the ROM
>> >Signature in the 9100/9010s? Have tried almost all the CRC programs I could
>> >download, none were correct. It's not CRC-16, CRC-32, CCITT, CHECKSUM....
>> >
>> >Anyone get any further?
>> >
>> >Attached is the file that I used to try and identify the signature and
>> >these are the results:
>> >
>> >CRC-16 =58B8
>> >CRC-32 =C1E6AB10
>> >CCITT =E63C
>> >
>> >(the "Correct" Fluke signature is = 8B1A)
>> >
>> >The file is from a video game, it's a 4K size chunk of the main program...
>> >
>> >John :-#)#
>> >

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Received on Sun Oct 13 21:43:36 2002