It sounds what you are looking for is a daemon to handle the actual communication. Basically in your scripts, you would pull in a module that knows how to talk to the daemon (sendto_wheelchair, retrieve, etc).

Unfortunately, in order to avoid using networking, you will have to use windows pipes (NT4, 2k, XP, etc).

I'm a little leery of using perl for the daemon given the time cycles (this sounds like it will require realtime scheduling) as I'm not sure if you can *consistantly* get the level of granularity out of the script.

That said, I have a vague memory of someone asking something similar in the microsoft.com newsgroups a couple years back but it was about running Visual Basic applications to interface with a wheelchair. A quick search on google didn't show anything. Thinking that such an daemon might be of use for many people writing applications for the wheelchairs.

btw, there was a person back in summer that wrote a magazine article about writing perl windows apps for a touch screen display for a disabled family member. For the life of me, I'm unable to remember the name of the magazine.

now, what you are trying to accomplish is closely tied with anyone performing jobs through a parallel port. You may do well to take a look at the 'hobbyist' angle as well.

hope this helps

jason