I forget the name, but I worked at a place ~1997 that had one that I'm pretty sure used regular board and pens. It had two bar-like devices affixed to a side and along the top of the board.
I remember that product. It seemed like a good idea, but it just couldn't keep up with writing at normal speed so we gave up on it. (You also had to put a special collar on the otherwise normal markers.)
Yes, the collars! I remember it had a kind of kiddie-name and maybe some blob-type design elements.