You can plug your keyboard into either PS/2 port. I spent about 5 minutes trying to figure out why Tracy’s keyboard didn’t work, and mine did, after moving our computers. I couldn’t see the back of either machine but I thought I remembered which socket was for the keyboard. Even though I guessed wrong, it worked on my computer, so I was confused why it didn’t work on Tracy’s computer even though I could feel that it was plugged into the same socket.
Of course, it still needs to be in the right socket to get into the BIOS menu so I’m going to change mine around as well.