Lots of tools I used stoped working with Win2K, so I had to make one machine dual-boot Win2K or Win98. Some tools got updates to make use of a driver, or the native API. Some of these updated tools never worked well, because of the timing issues introduced.

A bit of M$ documentation for accessing the parallel port can be found at:
http://msdn.microsoft.com/en-us/lib...85%29.aspx

But the M$ driver layer isn't so fun for real-life use, so third-party drivers are an easier route.

And of course, the best route is to ignore the parallel port. For a single signal, a RS-232 port can be used. And for many situations, a USB-connected device is the most general route to go.