[vcf-midatlantic] Workshop this weekend - Thoughts?

Jonathan Gevaryahu jgevaryahu at gmail.com
Sun Jan 31 17:24:26 EST 2016

Not that I am aware of. The BP-1600 programmer I use uses built-in 
functionality of the PLA to dump the raw original fusemap.

On 1/31/2016 3:36 PM, Douglas Crawford via vcf-midatlantic wrote:
> Another question related to this:
>>>> If anyone has an older 'breadbox' c64 (not c64c) with the signetics 
>>>> 82s100
>>>> PLA in it (only used for the first year or so before being replaced 
>>>> with
>>>> the MOS PLA) let me know, I'd like to try to read the fusemap out 
>>>> with an
>>>> 82s100 programmer. There exists a reverse engineered fusemap of the 
>>>> 82s100,
>>>> but it was done "by hand" using an eprom programmer to probe all 
>>>> the inputs
>>>> and look at outputs like a giant truth table, and based on an 
>>>> interview
>>>> with Bil Herd a few years ago, I now know that this will not 
>>>> produce an
>>>> accurate dump of the chip, because the engineeres at commodore 
>>>> played some
>>>> tricks by adding extra/unnecessary gates to certain outputs to
>>>> intentionally 'slow down' the edges of certain signals to prevent 
>>>> glitches.
> Any real risks to the PLA in reading in this fashion?

Jonathan Gevaryahu
jgevaryahu at gmail.com
jgevaryahu at hotmail.com

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