IBM Integrated Bluetooth IV with 56K Modem (BMDC-3)
IBM Partnumbers
IBM FRU PN: 39T0022 ($37.50 in July 2005)
This part takes the place of the 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, and another indicator LED on the top of the lid. To see these two LEDs, two new clear plates are required. The entire set of replacement sticker plates can be ordered as FRU 26R8409 ($12 as of July 2005). (formerly FRU: 13R2455)
Also known (in IBM literature) as....
Linux Bluetooth driver
The Bluetooth device is implemented using USB and can be enabled or disabled with the FnF5 key combination; enabling / disabling bluetooth leads to USB connect and disconnect events.
Bluethooth can also be enabled or disabled using ibm-acpi.
Some problems have been reported using bluetooth after a suspend/resume cycle on the T43. These problems can be mitigated by unloading the USB kernel modules (uhci_hcd, ehci_hcd, hci_usb) before the machine is put to sleep, and by re-loading these modules when the machine wakes up again.
Linux Modem driver
Although, the Smartlink driver for Agere modems is able to communicate with the modem via AT commands, it cannot dial out (contradicting reports welcome!).
If your favourite distribution does not include a hsfmodem driver (search for "hsfmodem" or "Conexant"), you can try the one from Linuxant: http://www.linuxant.com/drivers (14k free as in beer, 56k+Fax license 15$, they explain this policy under: http://www.linuxant.com/store/faq.php ) ha.