Starting with Drivers for other converters may also be present, but I have not used them. I have found FTDI devices to perform more consistently. Of the two, I found the open source PL driver to be slow and observed occasional data corruption I did not try the closed source driver but heard worse things. For instance, two common chips include the FTDI series official driver here and the Prolific PL chipset open source driver hereclosed source driver here. Given variability in driver quality and compatibility, you may want to try a few models and driver implementation. You probably want a USB to serial converter, of which there are a variety. The first step is to get an RS serial port on your Mac, which hasn't been built-in for a long, long time. I was working with The technique described here has been reported to work at least as recently as For completeness, here are some links to several of the sites I encountered, which should give you the basic idea of the problem. Many were quite old, and it appears that the process has gotten more difficult with more recent versions of OS X at least Snow Leopard People have generally had more success with the Xserve OS X server versions. I first tried googling around, and I encountered a few references to this issue on various Mac forums. One of two things is generally meant by this, either using a Mac as the interface to a serial device accomplished by running a terminal emulator program on the Macor using another machine to connect to the Mac over serial and accessing the shell provided by the Mac.