Making my dumb Microsoft Streets and Trips GPS work on my Mac

1) Download Prolific PL2303 Driver for Mac OS X. Install.

2) Edit /System/Library/Extensions/ProlificUsbSerial.kext/Contents/Info.plistChange idProduct and idVendor numbers to match those you get from the Apple System Profiler. Use the decimal values, not the hex ones.

3) Reboot. /dev/tty.usbserial should exist now.

Similar instructions at: http://www.osxhax.com/archives/000006.html