RE: ROM dumping woes (was: Re: Swedish CBM 3032)

From: Christopher Phillips (cphillips_at_reflectionsinteractive.com)
Date: 2002-02-06 18:28:39

Hmm.
It's probably worth doing some simple data integrity checks;
You could number and checksum blocks of 256 bytes, but
might be just as useful (and much easier!)
to do something like

 10 OPEN1,1,1,"ROM DUMP"
 15 PRINT#1,"HEADER";
 20 FORI=45056TO65535:PRINT#1,CHR$(I AND
255);CHR$(PEEK(I));CHR$(PEEK(255-I));:NEXT
 25 PRINT#1,"FOOTER";
 30 CLOSE1:RUN

so you can tell if you have missing start or end, or bytes randomly missing
or corrupted in the middle.



-----------------------------


> -----Original Message-----
> From: peter karlsson [mailto:peter@softwolves.pp.se]
> Sent: 06 February 2002 17:00
> To: cbm-hackers@cling.gu.se
> Subject: ROM dumping woes (was: Re: Swedish CBM 3032)
> 
> 
> peter karlsson:
> 
> > I'll have a better look into this tomorrow. Didn't sleep 
> too much this
> > night (was up to about 3:30am copying files)...
> 
> These dumps are broken, there are several bytes missing from them. The
> question is: did they get lost when I dumped them to tape on 
> the PET or
> when I read them back on the VIC? Does anyone know if the clock speed
> differences can cause problems here?
> 
> Basically, I saved them doing
> 
> 10 OPEN1,1,1,"ROM DUMP"
> 20 FORI=45056TO65535:PRINT#1,CHR$(PEEK(I));:NEXT
> 30 CLOSE1:RUN
> 
> on the PET and copied them to disk on the VIC back using
> 
> 10 E$=CHR$(0)
> 20 OPEN1,1:OPEN2,8,2,"0:ROM DUMP,S,W"
> 30 FORI=45056TO65535:GET#1,A$:IFA$=""THENA$=E$
> 40 PRINT#2,A$;:NEXT
> 50 CLOSE1:CLOSE2
> 
> (a simplified view of what I did)
> 
> Should I try reading the tape on my C64 or my C128, perhaps?
> 
> -- 
> \\//
> peter  - iDOC= - http://www.softwolves.pp.se/idoc/
> 
>   Statement concerning unsolicited e-mail according to Swedish law:
>   http://www.softwolves.pp.se/peter/reklampost.html
> 
> 
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