I've just seen a message on the Free-Online forum, in which someone has posted a reference to a Binatone support site from which the latest firmware and documentation may be obtained. The original post was in connection with the ADSL 2100 router, but I see the site also has other products listed. (ADSL500 anyone?). The site is:
(If you have a recent version of Internet Explorer, you can use that directly in your browser. For old fuddy-duddies like myself, that's just a fancy way of saying "FTP to 18.104.22.168 and log on with username "customer" and password "binatone".)
You'll see a whole load of folders amongst which are ones named ADSL2100 and ADSL500.