9th key pattern

[9th key pattern]

The late great Ken Uston had a book called Mastering Pac-Man that presented his friend's pattern for the 9th key. I remember it had a place or two where you had to hesitate for "a brief time, about 1/10 of a second." That drove me nuts. Despite trying over and over on an emulator, I never got the right amount of pause for the pattern to work.

[Pac-Man Plug and Play from 2007!]

I think the twisty unit also had Ms. Pac-Man, which had a bug where you could go into the tunnel and sometimes get stuck in the wall. Kind of the opposite of the Atari Pac-Man bug, where you can get stuck in the vertical column in the center and go through the walls.

[What were the arcades like back in 1982-1983?]

Question: were there any cooperative multiplayer games back in this time period? I'm struggling to think of any. Gauntlet didn't arrive until 1985.