Switch Interface Help

I'm in the process of wiring together a simple switch interface for my F-16 simpit and my pc froze and I lost the instructions! I can't seem to find the website after looking for hours and I can't remember what the switch interface was called. So I'm hopeing someone can point me in the right direction . . . all I remember is that it required 40 diodes, a few resistors, a printer cable, and some software. . . Ring Any Bells?