I want to write a simple script that will be able to send/receive signals over parallel port (LPT1) on Windows.
Does anybody know if there is a Lua library for parallel ports?
Not that I know of. There are som libraries  that can talk to the parallel port (does that still exist?), but you’d have to write a binding for it. Though from a quick glance it has only 2 functions, so that shouldn’t be too hard.