Their GDS I and II software operated on Data General Corporation's Nova and Eclipse line of 16 bit mini Computers. Sketches or layouts of electronic system were first manually drawn on mylar or paper to scale and were placed on large backlit 48 by 60 inch table digitizers. Using a moving stylus, these layouts were organized in layers, first placing the smaller common and custom circuits, created in a library, then manually traced their interconnecting circuitry on further layers, the completed layout then stored in computer files.