Many of the IBM ThinkPad 600E, 600, and 770 versions contain an
MWave DSP (Digital Signal Processor) chipset which, among other
things, emulates a Winmodem. IBM has provided a closed-source
driver for this device previously, but the new version is released
under GPL version 2.
The modem driver consists of a kernel module and a userspace
application. Together, the two components emulate the
Linux-standard serial port device (ttyS*) and a Hayes-compatible
modem supporting the "AT" command set.
Previous versions of the driver, released under closed source
licenses, remain closed source. The new, open source version
supports kernels from 2.2.16 onward, according to the source