Yo no tengo MAC pero se me ha ocurrido usar ese invento nuevo llamado Google y mira:
Busqueda: "terminal serie mac"
Resultados: CoolTerm
Mcwise
Zterm
Minicom
Por ejemplo...
Pero lo que mas inri tiene es que igual no sabes que el S.O. del Mac es practicamente un unix o linux, y tiene una terminal el mismo.
Si quieres usar la consola de MAC como terminal:
Solution: Use screen, Terminal, and a little AppleScripting.
First, launch Script Editor and type/paste in the following code:
tell application "Terminal"
do script with command "screen /dev/tty.KeySerial1"
set number of rows of window 1 to 100
set number of columns of window 1 to 80
set background color of window 1 to "black"
set normal text color of window 1 to "green"
set custom title of window 1 to "SerialOut"
end tell
Compile and save as an app from within Script Editor, and you have a double-clickable application to launch a serial Terminal session. You may want to customize this slightly -- you can change the screen colors or number of columns or rows. You may also need to customize the screen command with a different device name if you are using something other than the Keyspan Serial Adapter (do an ls tty* of the /dev/ directory to get the right name).
screen uses Control-A to take commands directed to it. So type Control-A followed by Control-\ to exit your screen session. If you fail to do this and exit a Terminal session, you'll leave the screen session alive and the serial resource unavailable until you kill the screen session manually. man screen will show you further commands to send to a screen session.
Es increible lo que inventan los ingenieros

Consejo: Es bueno aprender como funciona el ordenador de cada uno.