As a kid I used open up those handheld games beginning 80s to try to figure out how they worked; most has just 1 blob on the pcb which contained the chip and no

As a kid I used open up those handheld games beginning 80s to try to figure out how they worked; most has just 1 blob on the pcb which contained the chip and not much more but I did get some good results, like a Pacman clone had 2 blobs; one if them was a music chip which contained 100s of tunes mosty unrelated to Pacman; by figuring out what was the power and what was the signal to select the tunes (there was not much choice and if I remember the correctly the signal was serial). Great fun. Took me a lot of time and the games would be broken afterwards; luckily my parents liked that I was learning stuff instead of playing the actual games.