Yes, the other interface issue is trying to read bytes into the PSP as fast as they are
coming out of the GPS.
You should look at the data coming out of the eTrex Legend with a serial terminalI'm planning to interface a Legend GPS
to make sure it does what you want.
ie. it doesn't output the time from it's onboard clock when it doesn't have a valid fix,
and even when it does, it only outputs time every two seconds.