An operator station consists of a digitizing device, an interactive cathode ray tube (CRT) display unit, coordinate readouts and a keyboard. The main difference between stations is in the type of digitizing input station used. The Calma digitizer is a backlit 48 by 60 inch table. To digitize analog graphical data directly on computer-compatible medium, the operator of the digitizer manually traces graphical data with a moveable stylus. The graphic tablet has a smaller surface and is operated with an electromechanical graphic pen and were used primary to edit an electronic layout once it was digitized.