IBM Integrated Bluetooth IV with 56K Modem (BMDC-3)
IBM FRU PN: 39T0022
This part takes the place of the bare 56K Modem board. It requires a Bluetooth antenna, and some ThinkPads built without Bluetooth already have the antenna installed -- the antenna wire may be found disconnected and taped under the Modem board.
In addition to the Modem/BT module, a Bluetooth Thinkpad also uses an extra indicator LED below the LCD display. To see this LED, a clear plate (FRU: 13R2455) is required.
Also known (in IBM literature) as....
Linux Bluetooth driver
The Bluetooth device is implemented using USB and can be enabled or disabled with thekey combination
Linux Modem driver
Although, the Smartlink driver for Agere modems is able to communicate with the modem via AT commands, it cannot dial out (contradicting reports welcome!).
If your favourite distribution does not include a hsfmodem driver (search for "hsfmodem" or "Conexant"), you can try the one from Linuxant: http://www.linuxant.com/drivers (14k free as in beer, 56k+Fax license 15$, they explain this policy under: http://www.linuxant.com/store/faq.php )