The files
To run this place both files in the same directory and open a terminal window and use the command
halrun -I -f ptest.hal
You can push the output buttons and change the state of each output. When you toggle an input it shows up on the screen.
Enjoy BJT
A parallel port tester for an existing parallel port and a second parallel port switched to "in" can be found on:http://www.vdwalle.com/Norte/Second%20Parport.htm