Actually I never had any "programmer tool" There was a book about EIA programming.
Procomm or hyperterminal would work @ 300/1200 on a null modem. Flip the switch, the system goes down, enter a few times, then codes to get into interactive mode adn more importantly help. Then you need the codes from the book to make your changes. Typically programming off the phone WAY easier, but having the data dump was very valuable.