Originally Posted by PistolRogue
I believe it was markers fired via a microswitch, and not electronic in general. If I'm not mistaken that was part of why the Mini platform and later the newer Tippmann E-grips went with a Hall Effect sensor instead of a microswitch. Again, I could be making that up but I'm pretty sure I remember reading it somewhere that that was how it all came to be...
Smart Parts owned that patent. KEE may own it now, but I don't think the general public knows for sure.