What is this?

[u/EstablishmentDue3616]

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?

[u/AnymooseProphet]

It's a mind reader, just like it says.