My online PDP-8 is hung off the parallel port. If you use the iopl call to set privlages to do raw IO port reads and writes (must be root) then you can directly talk to the parallel port with inb and outb from a user program. I use the 1284 mode stuff which is probably more trouble than it is worth. outputs can all be controlled by the PC and I think read. The data lines can be bidirectional. If you want it I can send you the source for my parallel port I/O routines, email me. Also you can email if you have questions and see how much I remember. For the simpler modes the stuff I found online a couple years ago was pretty good. I don't seem to have any at hand but can dig them up if you haven't found anything good. David Gesswein http://www.pdp8.net/ -- Run an old computer with blinkenlights.