You "can" program almost the either panel without the 6139, you only need it for zone programming. Most of the time I don't install a programming keypad, but I always carry one on the truck...with long alligator clip leads on it. Any user programming can be done without the 6139. I highly discourage homeowners from programming their system if I am monitoring it...actually I don't allow it at all. If this is y our house you're talking about then install a 6139 or the newer programming keypad...I think the 6160 can program but double check on that..I cant remember fer sure.
There's also a secret way of programming without the 6139 but it's kinda goofy, so I don't do it much.