"port side of the computer" should read "starboard side". It's on the right-hand side when the computer is positioned normally in front of you.
Maybe I'm too used to running flight simulators on my Macs. But to us sailors or pilots, it would perhaps be clearer if the instructions mentioned "I/O port side" as Andrew did above.
Honestly, it never crossed my mind that 'port' refered to in/out…