PROMs and EPROMs, specifically 2332/2532/2732

Adrian Graham witchy at
Sun Oct 25 06:17:42 CDT 2015

On 25/10/2015 08:27, "tony duell" <ard at> wrote:

>> Further digging into available eproms that the programmer can read reveals
>> it CAN read 2532s, specifically the MCM2532 which the datasheet tells me has
>> the same pinout as the 2332. I still get "reverse insertion error" so I'm
>> guessing my PROMs are toast.
> As others have said, normally when putting a smaller chip into a programmer
> with a bigger socket you keep the 'bottom row' of pins -- including ground --
> in the same position for all chips. A look at the pinouts will show why. But
> as 
> you can read 2716s that's not the problem.
> Often 'reverse insertion error' means the chip drew the wrong supply current
> --
> often far too much. Which does suggest your ROMs  are dead :-(

Ah, OK, that makes sense. Bad ROMs and low-quality sockets are the chief
reasons for dying PETs so it doesn't surprise me. I've found some 2532s
pretty locally so hopefully they'll be with me on Tuesday and I can test
yesterday's soldering.

Wish there was a more local hobby/electronic shop here - I miss being in a
city but only for that reason :) Given that there are schematics for PET
testing boards like the PETVET I'd like to build my own. Nearest component
place is M*plins and they're not what they used to be.


Binary Dinosaurs creator/curator - the UK's biggest private home computer

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