There are a few things to do first;
a. Unless you have a serial port on your PC - new ones don't - you will need to purchase a USB-serial converter. Uniden sells the USB-1, and it's available from Scanner Master
b. You will need to install drivers so that your PC recognizes the scanner as a valid device. This article will describe the steps you will need to follow - it's set up for XP, but you should be able to figure out where to go using this as a guide. Note that anything in blue is a link, both here and in our wiki
Connecting scanners via USB - The RadioReference Wiki
At the bottom of the article is a link for the Uniden TWiki - it has a link for the Prolific website where up to date drivers may be found
c. While we don't have the instructions for the 996XT for allocating and configuring the 2 ports, we do have them for the older 996T, and I'm willing to bet they are nearly the same.
Here is the link to some brief descriptions of the procedure...
Connecting the Scanner to the PC - the RadioReference Wiki
d. Go get a copy of
FreeScan. It's freeware. The
user guide is in our wiki. You can use that to download, make changes, upload, and use the virtual controls.
73 Mike