FreeBSD driver for MosChip 7820/7840-based 2- and 4-ports USB serial ports
adapters.

  This driver supports all basic operations and all baud speeds for 2- or
4-port devices.

  Support for advanced features, such as IrDA or RS-485 modes and fine-tuning
will be added later.

Note that this driver will work with FreeBSD 8.0 (with USB2) or superior only.

WWW: http://lev.serebryakov.spb.ru/download/umcs7840/