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General Category => Technical Support => Software related => Topic started by: Audronic on 23:58, 07 January 16

Title: Help required to fix Checksum on a Utility rom Please
Post by: Audronic on 23:58, 07 January 16
Hi All
Help required to fix Checksum on a Utility rom Please.
Dropbox - UTILITY.ROM.zip (https://www.dropbox.com/s/izql3gdisk60cwr/UTILITY.ROM.zip?dl=0)


SORTED, The ROM is Faulty.


Thanks     Ray
Title: Re: Help required to fix Checksum on a Utility rom Please
Post by: TFM on 21:16, 08 January 16
You basically add the values from &C000 to &FFFE and keep the result in 8 bit. This byte then gets written to &FFFF.


Or you can use ROManager 2.14 to adjust the check-sum using the Test-ROM option.
Title: Re: Help required to fix Checksum on a Utility rom Please
Post by: Audronic on 01:00, 09 January 16
@TFM (http://www.cpcwiki.eu/forum/index.php?action=profile;u=179)


Thanks for the info, I did it the hard way
I used MegaFlash Romanager 464/664 Ver 1.45 (TFM)


To Test the rom, Update checksum, Dump rom to disk.
Compared   Rom1 Faulty CheckSum with Rom1 fixed CheckSum
Found the Byte that had been modified at &FFFF.


Thanks    Ray