> > I'd make the assumption that the "special conditions" would be zip under the
> > best compression supported by Mame.
>
> File date/time stamps, file attributes, file order, upper/lowercase, use
> zipcompressionlevel, used compressiontype, compressionratio (e.g. rezipped with
> zimaxed), etc..etc...they will all change the zip's hashvalues.

Maybe Add this feature to ZipMAX allowing ZIP normalization as option

Set all case to lower..
Set all file times to 01/01/1980
Set File order to alphabetical ....
this would allow standard HASH generation from multiple sources