Re: PET 2001 Fix....WAS: Will pay good money for NON working PET 2001 motherboard.

From: Ethan Dicks <>
Date: Mon, 23 Nov 2009 09:42:29 -0500
Message-ID: <>
On 11/21/09, Philip Lord <> wrote:
> Hi again,
> I just wanted to say a big thanks for everyones help, and to apologize
> for being such a dumbass for not being able to fix the board.
> Anyway, Ethan has the boards now, and has kindly offered to take a
> look at the problem for me. Thanks again Ethan.

So far, it looks like the one board with the PSU issues has fried
rectifier diodes - With ~9VAC coming onto the board from the brown
wires from the transformer, I get 1.8VDC at the inputs to the 7805s.

As for the other board, the one with the 2316 Character ROM on a 6540
adapter that seems to be flaky, I happened to have a 6540-010 ROM and
dropped it in place of the ROM adapter.  The board comes up, displays
the BASIC startup message, and runs a simple loop and print BASIC
program.  It's hard to read the 2316 Character ROM because of the rust
on the package, but it appears to me to read 901447-12.  This is
interesting because the only ones I was aware of online copies of are
-08, -10, and -14 (all of which I think I have in actual boards).  -12
could easily be a "lost" Japanese variant.  I just need to build a
6540-JEDEC adapter and I can read this out.

I don't think I have any 3A rectifier diodes lying about to fix the
one board, but they are under $0.20 from most suppliers.


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Received on 2009-11-23 15:00:10

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