[Techtoolslist] Eprom checksum

[Jose Luiz Martins]

Ops Sorry David... Now I realize your board is about 20 years younger them
nine!

JL


On Sun, Mar 31, 2013 at 11:28 PM, Jose Luiz Martins <
joseluizmartins at gmail.com> wrote:


> Uauuuu!!!!!!!!!!!!!!!!!!!!!!!!!  I was writing something like this to

> flippers when received your email!

>

> I'm facing exactly SAME problem with many Taito boards.

>

> Some 2716 and 2516 are even testing as blank!

>

> I did some research and the EPROM live time is guaranteed for about 10

> years, but many of my boards has between 25 and 30 years old.

>

> Called one friend today, asked him to test some boards and the result is

> the same problem.

>

> I think we should consider some plan against this suicide EPROM behavior.

>

>

> JL

>

>

> On Sun, Mar 31, 2013 at 10:36 PM, David Shoemaker <davids at oz.net> wrote:

>

>> 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

>>

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>

>