I was just curious why I scan some sets it will tell me the file is wrong CRC and some others it will say Unneeded File?

When I check the unneeded file rom the CRC is different compare to the dat file CRC. But instead of listing it as a uneeded why not as Wrong CRC?

IS it the way the dat file is made? I compare the one I am using to one that will show a CRC error and the only difference is that it shows the size.

For example I am scanning GBA files using GBAdat Pure from http://gbadat.pocketheaven.com/index.html

Here is what is listed for a file that tells me that it is uneeded...

game (
name "1010 - Iridion II (E-M3) by Eurasia"
description "1010 - Iridion II (E-M3) by Eurasia"
rom ( name "1010 - Iridion II (E-M3) by Eurasia.gba" size 8388608 crc 437519A2 )
)

Now I will take one of your dats Roman. Here is a 7800 Dat from you that will show a CRC error of a file I have...

game (

name "BadCode4 (Metal) (rom format) by Badcoder (2000) (PD)"

description "BadCode4 (Metal) (rom format) by Badcoder (2000) (PD)"

rom ( name "BadCode4 (Metal) (rom format) by Badcoder (2000) (PD).jag" size - crc 8f1586a9 )

)


As you can see the only difference is the size listing. Looking at the dats I see your lines aren't spaced in between each dat info, well in notepad it doesn't show this but here it does. But I wouldn't think this would make a different since the ( & ) defines the info.

Any reason what defines a CRC error compare to an Unneded file if the Rom has the right name and extention and size but the only difference is the CRC?

Here is the info of the GBA file I have that shows in Winzip...

Name: 1010 - Iridion II (E).gba
Type: GBA File
File Size: 8,388,608
Packed Size: 4,897,470
Ratio: 42%
Modified: 5/28/2003 8:13AM
CRC: 43B815AC

As you can see from what I have, compare to the dat info, it's the wrong CRC, but ClrMame tags it as an uneeded file instead of wrong CRC.

> As you can see from what I have, compare to the dat info, it's the wrong CRC,
> but ClrMame tags it as an uneeded file instead of wrong CRC.

The unneeded check is performed first. It scans the set and finds a not listed name (you current name is wrong). Then the name check checks the crc32 of that wrong named file and can't match it with a crc32 in the datfile. So the file is declared as unneeded and won't be touched by further romchecks like case, size and CRC32.

Roman Scherzer
ClrMamePro

> > As you can see from what I have, compare to the dat info, it's the wrong CRC,
> > but ClrMame tags it as an uneeded file instead of wrong CRC.
>
> The unneeded check is performed first. It scans the set and finds a not listed
> name (you current name is wrong). Then the name check checks the crc32 of that
> wrong named file and can't match it with a crc32 in the datfile. So the file is
> declared as unneeded and won't be touched by further romchecks like case, size
> and CRC32.
>
> Roman Scherzer
> ClrMamePro
>


Ahh ok, so if the name was correct originaly then it would show the CRC.

Thanks again Roman :)