howto rig up a computer at home to a cellphone with a cable and set it to automatically answer any incoming calls. Basically, the phone acts like a modem. It's supposed to be used for transferring data in emergencies (i.e., from a payphone). hacking Uses a piece of hamradio software called CallTTY, which implements tty and ttd (Telecommunications Devices for the Deaf) in software instead of hardware.