Adding a Serial Port to a Mac
If you need to sync an old Palm device with only a serial connection to a Mac, you’re going to be up a creek. Modern Macs aren’t shipping with serial ports, but all is not lost. The Keyspan USB Serial Adapter works and works well. I had the opportunity to test a few Palm devices, the earliest being the m105. The devices sync without issue thanks to the fact that a) the adapter draws power from the USB port and b) Keyspan includes a driver disk so your machine knows the adapter is present.