This is quite innovative, at the time most 'digitisers' had a pantograph arm with a couple of potentiometers going into a A to D converter plugged into a parall

This is quite innovative, at the time most 'digitisers' had a pantograph arm with a couple of potentiometers going into a A to D converter plugged into a parallel port. Such systems cost a fortune and suffered from analog noise problems. The 'digitiser' survived for a while in things like GIS but what Apple was doing with their tablet won long term.