Serial Over USB on OSX via Screen!

Had to configure a Cisco firewall for the first time in literally YEARS today and ran into a few small hurdles. Mostly, my MacBook doesn’t have a serial port nor a HyperTerminal like program. Never fear, however, there are USB to Serial adapters out there that have OSX drivers… that’s where we meet challenge the first:

USB to Serial Drivers for 10.7

Disclaimer: You likely don’t want to go randomly installing 3rd party kernel extensions… but who am I to tell you what to do you your gear.

This site here has some kernel extensions that have been made to work with OSX 10.7. Basically, download the .tgz file and follow these instructions:

  • download and extract
  • cd /path/to/osx-pl2303.kext
  • cp -R osx-pl2303.kext /System/Library/Extensions/
  • next you need to fix permissions and execute bits:
    • cd /System/Library/Extensions
    • chmod -R 755 osx-pl2303.kext
    • chown -R root:wheel osx-pl2303.kext
  • kextload ./osx-pl2303.kext
  • kextcache -system-cache

From there, now  you need to actually connect to things. Thanks to Greg Ferro at for this post that will get you the rest of the way.