In this simple application of the 68HC68 microcontroller serial-I/O utility, the goal is to configure a simple circuit, driven by any LPT parallel-printer port, which you can use as a remote I/O for a PC. You can independently program each I/O line as eit
http://www.edn.com/article/CA159689.html
only been tested on an old TTL-style printer port, not known if works with modern ones
http://www.6502.org/users/andre/ieee488/index.html
Schematics for a simple printer port project . Includes code for Visual Basic , QBasic , C and C++.
http://www.programmershelp.co.uk/printerport1.php
example of controlling a relay from the PC parallel printer port
http://ourworld.compuserve.com/homepages/Bill_Bowden/page6.htm#PPRIC
http://www.epanorama.net/circuits/parallel_output.html
12-bit analog I/O board that plugs into a PCs printer port
http://www.edn.com/archives/1995/020295/03di2.htm
venerable parallel-printer adapter has found many uses during its long lifetime
http://www.edn.com/archives/1995/062295/13df3.htm
16bit Output Interface for the Parallel Port
http://www.geocities.com/fishziblu/lpt16io.html