My version of the complete fix started in July 2009, about a month after buying the PET from Yahoo Auction Japan.
It arrived DOA, The first thing I did was to replace the caps and 7805's in the power circuit, but that did not help. Fortunately Ethan Dicks from the cbm-hackers list was kind enough to offer to take a look at it if I sent it to him. In the end I sent him two PET 2001 boards. The other had been given to me and was also in some trouble. Ethan was able to get the other board fully working, and fix the power circuit in the Japanese board.
So the complete list of thanks and fixes are:
• Ethan Dicks - Replaced dead diodes in power circuit.
• Burn new character ROM (CHARGEN ROM) as the original was dead.
• Ruud - For writing a test program that could be written to an EPROM and used in troubleshooting.
• MikeS - For suggesting to replace the 74LS165 at B2 to fix the vertical line problem and for also suggesting to remove C8 (C8 was actually ok, but doing this allowed for much more detailed testing).
• dave_m - For finding the final fix for the offset characters. 74LS00 at D8.
• André - For following this fix from cbm-hackers to VCF, and for his brilliant timing diagnosis which pointed us all in the right direction for the final fix.
• Nicolas Welte - For correctly diagnosing a build issue with the RAM/ROM board I was using for testing. I had placed the resistor pack in the wrong way. The other issue with the RAM/ROM not booting BASIC4 was solved by me, as the Flash ROM which came with the board was corrupt. I also built one of Nicolas's 6550 video RAM replacement boards which was installed in the machine too.
• Anders - For sending me a keyboard from a PET 3000 series machine. I built up an adaptor to connect it to the 2001. Works great.
• Matthew D'Asaro - For making the PET composite video adaptor, which was invaluable for testing.
Hopefully I have remembered everything correctly.
Well, I'm sure there are more people to thank, but I think this list covers off on the top 8. Thanks everyone.
I learnt a lot of things during this fix, in particular I learnt how to use a scope for basic testing.
I have to say I feel a little sad that the machine is fixed. What am I going to do with my evenings now?…Oh yeah, I'm going to try out the floppy drive and I/O interface that Tezza sent for my Dick Smith System 80
Thanks again everyone.
Phil