The DigiTemp program for Linux, DOS and Windows 95 uses a simple serial port adapter to communicate with the Dallas DS1820 digital temperature sensors. This protocol requires only a ground and a data wire to the device.
All power is derived from the data line while it is idle.
Each byte sent to the serial port represents one data bit to the DS1820. Wire cutters and a soldering iron. In this document I will refer to the pin functions. I have not built a DB-9 version myself. Please let me know if you successfully build one or have problems with it.