Ok, I've done my research and it appears that threading isn't supported on a Mac by FPC/Lazarus . Reading it appeared that I should setup my own TThread structure. I modified my code to use MPCreateTask and MPTerminateTask but it still crashes when the thread spins up .

Any ideas on how to properly spin up and execute a thread on a MAC?

You can see my attempt in the ATerm demo I posted in the macClient.inc file. Download at: http://www.eonclash.com/ in case you don't want to go searching for it