Going to upgrade the memory or leave it original & matching the nameplate?
Well, what made me get it out to fix after having it for several years was seeing the demo called "No PETS Allowed", and I thought it would be cool to see it on a real PET. But I'm torn. 4016s don't seem very common, and there's something about keeping it stock. Still thinking about that one.
Good luck with the disk drive issue; cable & connector good? Correct device ID?
I had cleaned the connectors, but apparently not well enough. Cleaned the IEE-488 connector again, this time using my wife's jewelry cleaner. Then I also screwed the MB down to eliminate the possibility that my problem was a poor ground, and the 4040 works!
Last, I put the original RAM chips in one at a time, and it turns out there were two bad ones. I decided to see the "piggyback test" for myself, so putting in one bad 4116 at a time, I pushed one of my new good ones onto the bad one, and in both cases, the computer came up, and like you guys said, showed an unusual number of bytes free. That was a neat experiment. I don't think it would have worked during the initial troubleshooting for two reasons: First, I had two bad ones, and both were preventing the PET from booting. Second, the pins on the old chips were so tarnished, my new ones probably wouldn't have made contact. This worked because they all have sockets now, and the piggybacked chips actually reached down to touch the sockets. I've learned a ton on this project!
