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…
"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.