Re: very strange C64 fault

From: Francesco Messineo <>
Date: Sun, 23 Apr 2017 19:24:28 +0200
Message-ID: <>
On Sun, Apr 23, 2017 at 7:16 PM, Gerrit Heitsch
<> wrote:
> On 04/23/2017 06:53 PM, Francesco Messineo wrote:
>> Hi All,
>> final update: it was the CPU, fortunately it was temperature
>> sensitive, so when cold it would take a few minutes to show the fault.
>> So cooling the various chips with compressed air just showed the real
>> culprit.
>> It's my first broken 8500 and also the only 8500 spare was used to fix
>> the C64C :/
> You can use a 6510 as a replacement.

sure, if I had one :)

I've never had many spares, almost all of my spare chips are from the
'80s when I kept a small stock (1 for each part, mostly) to test the
broken computers that were brought to be fixed. I would then order the
spare once I identified the problem.
Back on the '80s, Commodore spares were cheap and one week away from
the day of the telephone order.
I had one spare CPU (8500R3 from 1985) that could be used for both
6510 and 8500 boards.
Now the partly working 8500 from 1989 that I changed on my C64C will
be uses as test for really dead CPUs (if any) in future
This 8500 is also my only C64 CPU in the broken MOS chip collection so far.

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Received on 2017-04-23 18:01:49

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