Texas Instruments TI-81 ViewScreen

The TI-81 ViewScreen is the teacher version of the standard TI-81. It connects with a special port permanently to a ViewScreen panel via a flat-ribbon cable. Placing the panel on the overhead projector enlarges the image of the handheld screen so that each student can follow along. From a technical point of view the TI-81 VSC is almost identical with the students TI-81. The main difference you notice is a two piece bottom shell of the calculator housing to accommodate the ViewScreen electronics.