[updated:LAST EDITED ON 29-Dec-01 AT 02:11 PM (GMT)]Go to the very informative http://www.sathelp.co.uk and follow the link to analogue satellite, there you can get a demo of Pacelink.
PS. Just traced the link and it goes to the Pace site which no longer seems to supply the software. You can try writing to firstname.lastname@example.org who sell the interface and may be able to provide you with the siofware. If not go to any large satellite installer and they may sell you an old version.