It's a modem. It doesn't use a "driver". You just access it as a serial device, and issue it commands via serial connection.
Example: PPP software would issue all the commands automatically, you just tell it the phone number, and it handles all the commands.
Example: Terminal software would just open a straight terminal connection, and you'd enter "ATDT 8005551212" (for example) to dial a phone number to make the terminal connection (in this case, to the phone number 800-555-1212, obviously you'd replace it with the number of the system you are connecting to.) Once the modem makes its connection, you'd have your terminal connection to the remote machine.
Example: PPP software would issue all the commands automatically, you just tell it the phone number, and it handles all the commands.
Example: Terminal software would just open a straight terminal connection, and you'd enter "ATDT 8005551212" (for example) to dial a phone number to make the terminal connection (in this case, to the phone number 800-555-1212, obviously you'd replace it with the number of the system you are connecting to.) Once the modem makes its connection, you'd have your terminal connection to the remote machine.