A signature starts with a seed (e.g. 0000) and each byte is sort of xor'd and
shifted into the seed, to give you a result.
A checksum will miss double errors in different bytes, where they cancel each
other out, whearas a signature (depending on the xor function used to create it)
can be statistically proven to spot certain patterns of errors.
If a signature is right, you're virtually guaranteed the ROM is OK. Checksums are
a bit dodgy by comparion.
Phil
On Wed Sep 14 9:38 , 'Matt Rossiter' <matt@verio.net> sent:
>By the way, can someone explain the difference between a fluke signature and
>a checksum? Sometimes my fluke reports a bad rom signature, but that
>doesn't necessarily mean the rom is bad does it?
>
>Matt
>
>-----Original Message-----
>From: techtoolslist-bounces@flippers.com
>[techtoolslist-bounces@flippers.com] On Behalf Of John Robertson
>Sent: Tuesday, September 13, 2005 4:32 PM
>To: Technical Tools Mail List
>Subject: RE: [Techtoolslist] James has been busy!
>
>Let me sell off my 9010A bases before someone makes a PC interface
>for the pods!
>
>Sigh.
>
>I agree though, that would be best - a number of people have looked
>into it and said they were going to do it...nothing so far though.
>
>John :-#)#
>
>At 7:25 PM -0400 9/13/05, James Bright wrote:
>>Yeah, that's his name. The source code was there... or mostly there....
>>if I recall. It's not really all that tough to do because the scripts
>>that are delivered to the 9010A are really just keystrokes encoded a
>>specific way. The tedious part is that implementing a parser/syntax
>>checker/compiler and that is really not a whole lot of fun from a
>>programming perspective... BTW, by looking at his code was how I figured
>>out a little bit about "thunking down" to the z80 code.
>>
>>A much more interesting project would be an adapter to control the pods
>>from a PC. Quite a bit of work to get that completed (which is why I've
>>been keeping my eye on some of the Fluke emulation work), but it would
>>open up the possibility of using a more structured language to write
>>scripts. For example, wouldn't it be nice to use a CRC check instead of
>>a Signature check for ROMs... which is a little hard to implement with
>>existing script language.
>>
>>I'll start thinking about what enhancements I can do with
>>tech.quarterarcade.com.
>>
>>JB
>>
>>
>>--James Bright
>>www.QuarterArcade.com
>>Restored Arcade Games for your Home
>>
>>> -----Original Message-----
>>> From: techtoolslist-bounces@flippers.com [mailto:techtoolslist-
>>> bounces@flippers.com] On Behalf Of John Robertson
>>> Sent: Tuesday, September 13, 2005 2:12 PM
>>> To: Technical Tools Mail List
>>> Subject: Re: [Techtoolslist] James has been busy!
>>>
>>> No, there is another one, written by a Fredric L. Rice that he gave
>>> to the Fluke community (it's on the FTP somewhere) back in 2002. I
>>> don't think he included the source code though. I have sent him a
>>> note to see if he is interested in parting with that - assuming his
>>> email still works!
>>>
>>> John :-#)#
>>>
>>> At 6:50 PM +0100 9/13/05, Martin White wrote:
>>> >Don't forget that the compiler is just the command line one that
>>> >came with the 9010a. Therefore proprietry.
>>> >
>>> >I think!
>>> >
>>> >On 13 Sep 2005, at 18:32, Christopher X. Candreva wrote:
>>> >
>>> >>On Tue, 13 Sep 2005, John Robertson wrote:
>>> >>
>>> >>>The scripts run on the Fluke 9010A (Z80)...or are you speaking
>>about
>>> the
>>> >>>compiler?
>>> >>>
>>> >>
>>> >>I was, sorry.
>>> >>
>>> >>
>>> >>==========================================================
>>> >>Chris Candreva -- chris@westnet.com -- (914) 967-7816
>>> >>WestNet Internet Services of Westchester
>>> >>http://www.westnet.com/
>>> >>_________________________
>>>
>>> _______________________________________________
>>> Techtoolslist mailing list
>>> Techtoolslist@flippers.com
>>> http://seven.pairlist.net/mailman/listinfo/techtoolslist
>>
>>
>>
>>_______________________________________________
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>
>
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>
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Received on Wed Sep 14 04:54:28 2005
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