So J.C. Wren's tool worked. He also helped me getting something to read the parallel port on Win32 platforms using Perl, so I was able to write the interface between the ADREMO wheelchair and pVoice. It's not beautiful yet. It's more a quick hack. Now I have to think of a way to implement the ways of controlling pVoice using different devices as a modular thing.
At least I have to write a module for every different device, but I'm not quite sure how to implement it. In a configuration utility the user should be able to select the right device for him or her, so it must be a pretty transparent interface.
Maybe I should write Device::Parallel for CPAN first. But I would still have to find a way to read that port from Unix variants. Of course there is always