Hi Rafael,
you should divide your problem into two steps - first a simple output/input should work and then step two: bidirectional operation, if needed. Find attached a simple prog, that writes and reads some values to/from LPT - use a scope for test or a DMM in debug mode - file.png shows bahaviour at bit0 & bit1 (used OS - WinNT). In addition you need accesshw installed on your machine. If there are still open questions - write to: werner.hasche@web.de
regards
wha