The link to test out talking to the rio server from the web browser is still 404 so i was not able to test that.
Well, I'm home now so I've got files on my local hard disk which describe the same things from Roger back when he was emailing them to me.
Here's some examples of how I queried my Rio Central (which has the address of 192.168.0.4):
Type this in your web browser:
http://192.168.0.4:12078/content/100?_extended=1
This results in a response like this:
3760=P(Low Key)
3c80=P(Workout)
5620=Ptemp
(...)
Those are root playlists, if you have any (they have a P there, see it?)
Type this in your web browser:
http://192.168.0.4:12078/content/3760?_extended=1
Note that I am entering the playlist's FID in the URL above. This results in a response like this:
3ee0=TLessons
3ef0=TTears
3f30=TCloser to the Heart
3500=T'39
3520=TSeaside Rendezvous
(...)
Those are tunes (See the "T" in there?).
Type this in your web browser:
http://192.168.0.4:12078/content/3ee0
Note that I am entering the tune's FID in the URL above. This results in, assuming your browser knows what to do with it, an MP3 which then plays automatically.
If you don't have any playlists, try something like this to get a list of tunes:
http://192.168.0.4:12078/results?source=2112&_extended=1
3eb0=T2112
3ec0=TA Passage to Bangkok
3ed0=TThe Twilight Zone
3ee0=TLessons
3ef0=TTears
3f00=TSomething for Nothing
There's more detailed stuff you can do with the queries, but that's your basic level of test to see if the laptop on the backside of that linksys router is able to get the stuff off the server the same way the receiver gets it.