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rjsquirrel
July 8th, 2005, 01:24 PM
I decided to try and revive my Commodore PET 2001 that has been in the basement for many years (I'm the original owner). When I turn it on, the screen is filled with seemingly random alpha-numeric and graphic characters. They are static, but vary somewhat in configuration if I cycle the Power. Does anybody have any suggestions? Thanks.

Kaptain Skitzo
July 10th, 2005, 05:31 PM
Shoot it. :shock: :lol:

Just kidding. Seriously, I'd take the case off and give it a really good cleaning. Chances are, being kept in a basement, some moisture crept inside there and caused some mold. Use 70%(minimun) rubbing alcohol, let it dry(should only take minutes)...then try kicking it up with the case still off. That way, if the cleaning didn't help, you don't have to take it apart again to effect repair.

true2u1
October 5th, 2005, 04:54 AM
I have an old PET 2001-8 and it has the same problem. I have tried cleaning it and re-seating the ICs to no avail. I read a post elsewhere that it may be one of the capacitors on the 555 timer. It is supposed to activate the processor reset. I have not tried it yet, but I obtained a great book off ebay called "The PET Revealed" that has a great schematic.

I also discovered that the drive belt in the datasette is rotted and broke. In my experience with an old VCR that had drive belts, you can measure the belt dimensions as best you can and they can be purchased any number of places (electronic supply, online).

If I can get the thing work, the next thing to do is find some software for it!

billdeg
October 18th, 2005, 06:54 PM
This is indicitive of a RAM problem. Try re-seating the RAM chips (front left bank of chips) if possible. How many rows of RAM chips are there? If there are two (it's been upgraded), you can take out the back row/swap them around. You only need the first row.

Be careful!