Calculating the Checksum

[Roger Heflin]

Well, on a 93 Z28 A4 that seems to be where the checksum is also.   My eprom
is a 32k eprom.

It is going to have to be the same address for all chips used in the same ecm,
I think the builting stuff may check the checksum to know if the chip is good.

				Roger

On Thu, 10 Sep 1998, Ross Myers wrote:

> After my recent experience in disabling the VATS check, I am now wondering
> how the Checksum is calculated.
> 
> For the VATS it was kinda easy, as the disable signal ment taking 10h off
> $0014, then taking 10h off the checksum bytes $0006 & $0007 (This is the
> same address for 88 & 89 Vette isn't it?, anyway it worked, no code 51, and
> checksum was still enabled).
> 
> But lets say I change lots of values, what bytes get left out of the
> checksum value?. I know you don't add all of them up, so where?
> 
> Is it the same address' for all chips used in the same ECM?.
> 
> Thanks
> 
> Ross Myers
> 
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