Concept Keyboard / Star Microterminals A4-128

The innovation was not electronic but conceptual. A printed paper overlay — typically A4-sized — was placed on top of the keyboard and held in place by corner clips. The overlay mapped pictures, words, or symbols onto the touch zones. When a child pressed the picture of a cow, the computer received zone code 47; the educational software knew that '47' meant 'cow' in the context of the farm-animals overlay. The same zone 47, under a different overlay, might mean 'FORWARD 20' in a Logo turtle programming activity. The overlay was passive — the computer could not detect which overlay was in use — but the reconfigurability was real: the same hardware became a completely different interface through a simple paper swap. This was a pre-touchscreen, pre-GUI approach to making computers physically accessible, and it prefigured tangible computing by over a decade.

For children who could not read, the Concept Keyboard collapsed the literacy barrier. Instead of typing words they could not recognise, children pressed pictures. For children with motor disabilities, the large touch zones (approximately 18 × 52 mm each) made computer access physically possible where a standard keyboard was not. The interaction philosophy was that the interface should adapt to the user, not the user to the interface — a principle that became central to accessibility HCI decades later.

The Concept Keyboard embodied several ideas that would later be formalised as 'tangible user interfaces' (Ishii and Ullmer, CHI 1997): physical objects (paper overlays) mapping to digital functions, reconfigurable physical interfaces, and non-screen-based interaction. Unlike later tangible interfaces, the overlay carried no digital identity (no RFID, no barcode, no conductivity pattern), but the human factors insight was the same: sometimes the best interface is one you can hold in your hands and swap like a placemat.