I just pulled my 305 out of a box where it sat unused for 5 years and it still works. Yay!
I just had to download the PC drivers and the Communicator browser plugin, and then replace the HRM strap battery.
I found that it does not work with Garmin Connect website in or with Attackpoint on Chrome browser.
But it works with Attackpoint on IE! Excellent.
I'd suggest installing Garmin Express on your pc, then you can use the attackpoint gc_web_sync to pull them into AP: http://www.attackpoint.org/garmin-connect.jsp
(not sure if you need to donate to get this)
Still using mine, actually have several , as I resurrect old ones others have given up on. (usually a battery replacement).
Speaking of battery replacement. the June 2016 issue of Compass Sport had an article on how to replace the battery
I installed Garmin Express. Then I was able to sync the 305 activities to Garmin Connect. Then I was able to import those activities from Garmin Connect into Attackpoint using Chrome.
It is nice to use Chrome, but that seems like a circuitous route to import training session data into Attackpoint. Am I missing some other advantages of this method?
GC import is manual for AP, but if you use other tracking sites like Strava, Citystrides etc then GC can push new workouts automatically.
As cmorse says I use it primarily to push to Strava, then pull into here. A bit circuitious but apart from the AP bit it all happens automatically for me as I have a bluetooth connection from watch-phone, so the only bit I actually do anything for is the AP bit. It would be a bit more work for a 305...
Thank you. It is working fine now. Garmin Express and Garmin Connect are importing the workouts automatically when I connect the 305 to the PC. The final step of importing into AP using the gc import function is all that I need to do each time. I like it.
I gave up using mine after I got a Fitbit Surge. I had a lot of trouble with the charger.