Groundspeak Forums -> Gps With Mac's: "First of all, I should say all this takes place with a 12 inch, G4 iBook with an 800 Mhz processor, 256 MB RAM, and Panther 10.3.3. Thankfully, OS 9 did not have to come into play at ANY point.

I have a Garmin eTrex, the regular ol' yellow base model which ran about 100 bucks when I bought it a few years ago. My first task in marrying the iBook and eTrex was purchasing the proper cabling, and the cavemen from prehistory who make GPS data cables still work with 9-pin serial ports. That would be great if this was 1997, but nowadays most Macs are strictly USB and Firewire. So i needed 1) a GPS data cable that ran from the back of the eTrex to a female 9-pin serial connect and 2) an adapter to plug that 9-pin serial into a USB port. "