Each piece of hardware (barcode scanner, card reader) has proprietary driver and software that is most often NOT shipped with it, however look on your manufacturers website and check for a support, drivers, or a download link. From there you should be able to look up your model number and select the software you need.
Next, your software should allow you to send a character to your computer before it sends the data it scans. You define that character (on my system I programmed an asterisk). In TD, on the Hotkeys tab, I programmed a new hotkey with the asterisk as the hotkey and the command it sent to TD was to buy-in players. The Auto-Seat and Paid In Full were all checked (as well was the Auto-Print on the Preferences Tab>Print). When I swipe a card, it sends an asterisk to TD which initiated a Buy-In Players dialog. The number on the card scans into the search field and TD automatically looks it up. If the Auto-Perform action is not checked, you should now check it off. With auto-perform checked TD will buy-in the player, produce a table and seat and a receipt (if you are using receipts)
Jody