[Techtoolslist] Eprom checksum

[David Shoemaker]

Working on a Midway grid.  Board is reporting bad checksums on some roms.
The roms have checksums written on them (factory labels with handwritten
info).

 

Put a rom into my EMP20 (which I have never used for this size rom before)
and then had it calc the checksum.  Doesn't match the notation on the label.

 

Loaded a mame rom set into the software and got a different checksum from
both my rom and the file.

 

Doing a file compare against the rom loaded into the buffer and the rom in
the socket shows dramatic differences.

 

I tried this with one of the roms that the board is reporting as good and
got the same kind of results.

 

So now I don't know what to trust.

 

I wanted to calc the checksums of the mame rom images but can't figure out
what tool to use (running windows here).

 

Any help appreciated.

 

David