Re: PET 3032 alive :)

From: Francesco Messineo <>
Date: Thu, 2 Feb 2017 20:32:48 +0100
Message-ID: <>
On Thu, Feb 2, 2017 at 8:30 PM, Gerrit Heitsch
<> wrote:
> On 02/02/2017 08:26 PM, Gerrit Heitsch wrote:
>> On 02/02/2017 07:32 PM, Francesco Messineo wrote:
>>> And it's dead again :(
>>> I was typing the cbmlink bootstrap basic program.
>>> I saved it on tape and I was trying the first test runs as it just
>>> died on me.
>>> Now at reset it clears the video memory and sometimes it displays a
>>> few random characters but most of the time the screen remains just
>>> blank.
>>> I'm going to try to substitute the kernel ROM since on one of my
>>> programmers refuses to read entirely (on another one reads fine every
>>> time).
>>> With no kernel ROM, the screen remains full of characters as it should.
>>> Ok... old hardware isn't so easy to fix after all.
>> Could be a bad RAM. As far as I know, the 3032 uses 2 banks of 4116
>> DRAMs. You can swap both banks by desoldering and then crossing 2
>> resistors. If it's RAM, that should make the system behave differently.
>> Which ones? For that I would need the schematics... Anyone have them?
> If the schematics at
> fit your board, it would be R41 and R42 which you'd have to cross to swap
> the banks.
Thanks for the suggestion. I'm going to try also with the pettester
kernel that I just downloaded and written to a 2532. If I don't get a
better clue, I'll swap the resistors in a few minutes.

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Received on 2017-02-02 20:01:59

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