On Mon, 1 Oct 2001, Ruud Baltissen wrote:
I have several 2031's. I have not run into this specific problem, but
have had similar problems where the chips do not seat in the socket
properly. You could try spreading the pins apart so that when you insert
the ROM it is a very tight fit. Moving the ROM back and forth in the
socket also helps to make good contact. Those sockets are not very good
quality and sometimes the socket contacts get bent down. Try using a
magnifying glass to check the contacts.
1541 ROM's will not work in a 2031. They will not even complete the self
test.
> Hallo allemaal,
>
> I borrowed a 2031 from Arndt to check out the differences between this drive
> and the 1541. So I checked the circuit and read-out the ROMs and gave the
> 2031 back to him. He powered it up and it started to flash three times:
> brooken second ROM :( I promised Arndt to have a look at it.
>
> I just read the ROMs, hadn't even checked the contents. So I checked them by
> comparing them with the images on FUNET: no problem. So I read both ROMs
> again and compared them with the original read outs: no problem. It looked
> like an hardware error, maybe something went wrong with addressing the
> second ROM. But how to check that? I'm working on a 6502 debugger but that
> would take some dayswork yet.
>
> Then I got this idea: except the IEEE-bus, the 2031 and 1541 are the same.
> So IMHO I could swap both sets and the drive should power on normally. The
> 2031 with 1541 ROMs powered on as it should and the 1541 with the 2031 set
> started to flash.
> I even went a step further, I tried the drives with mixed sets. And every
> time the drive with the second 2031-ROM started to flash.
>
> So I checked the read-outs and the ROMs again: all were allright. But I must
> say I had a similar experience in 1988: a self built computer refused to do
> anything allthough every part looked fine, including the self burnt EPROM. I
> replaced the EPROM and the computer worked fine.
> With this in mind, I suspect that this ROM has become "senile" as well.
> (Anyone has another description?)
>
> Why the above story?
> - Has anyone else experienced this before with a ROM? Or are it infact
> OPROMs?
> - I wanted to mention the used trick.
> - Has anybody a spare second 2031 ROM?
> - I have these Motorola pin compatible EPROMs (forgot to note the number)
> but haven't any programming data on them. Anyone has please?
> ___
> / __|__
> / / |_/ Groetjes, Ruud
> \ \__|_\
> \___| http://Ruud.C64.org
>
>
>
>
>
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