[sdiy] EPROM conversion question

[klosmon]

At 01:13 PM 3/23/2006, you wrote:
>On Mittwoch, 22. März 2006 03:28, klosmon wrote:
> > for the rev 2 version 7.0 -- for some reason, this version will NOT
> > work when copied into a 2716.
>
>This sounds like somehow this particular firmware is accessing locations
>outside the normal memory map and is expecting to see something
>specific, which would depend on the details of the address decoding,
>chip enable and perhaps what a non-enabled (hi-Z) EPROM output reads as
>in that particular circuit - this could be all ones, all zeros, random
>or the last data on the bus before all outputs were going hi-Z. The
>last one resulted in one of the hardest to find bugs I've witnessed and
>luckily I've seen this only once. The things that are easily verified
>is putting a copy of the low half into the upper half and putting all
>zeros or all ones there. If that doesn't work, then you'll probably
>have to jig up the enable input so that the EPROM is unselected for its
>upper half.
>
>
>Achim.

I'm becoming convinced it's some kind of incompatibility with the 7.0 files 
& the 2716.  Thanks to everyone's suggestions, I tried loading the same 
software into the upper portion of the chip, loading the upper portion with 
all ones or all zeros -- same non-workng deal.
Much appreciation to all who responed on list & off;  I'm going to have to 
bag this problem for a while, until such time as I can devote some serious 
study to the programming aspect -- looks like the only way to solve this is 
to take the file apart, bit by bit.

Much thanks,
~GMM