Why did many commodore 64 games require the joystick to be in port #2, despite being single-player games?
I remember being annoyed by having to unplug and plug the joystick between games.
I never really thought about that much as a kid, when I had my C-64 (we just left a joystick plugged into #2 all the time).
However, after some digging, according to Ode to Joysticks:
Port 2 eventually emerged as the default, mainly because joysticks plugged into Port 1 could interfere with the command line interface.
Which is a good point, now that I read that, I do remember that having a joystick plugged into port #1 would send bizarre key codes to the primary BASIC interpreter/command line.