The developer's resource for computer interfacing, ethernet and internet communications for embedded systems, USB, mass storage, parallel port, RS-232 and RS-485 serial communications, info about 8052 microcontrollers and making printed-circuit boards.
A collection of files and links to material about the PCs parallel port, including ECP, EPP, bidirectional, and IEEE-1284 modes (and other I/O ports as well). From Jan Axelson.