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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