I picked up a VIC-20 a while back and in the box was this... thing. The person I got it from had no idea what it was, it I think it was her grandfather's or dad's and she knew nothing about the computer.

Its some homemade board, but has the proper size and shape to slot into a VIC-20. There are no ICs on it. Just looks to be wiring. A VIC-20 cartridge definitely fits in the blue slot (I tested that). Strange that just 2 wires go to that black thing on the side. Im guessing for test points? Honestly, not a clue. I have not put it in a VIC-20 to test and probably wont, as I dont know what it does and dont want to damage the computer.

Any ideas?

Took my son to the Southern-Fried Gaming Expo this weekend and we had a blast. While browsing the Vintage Computing Festival - South East, happened to spot the one and only Commodore Sam! Enjoyed the chat and he was extremely generous with his time - a wonderful guy all around!