Graphical Layout System for IC Mask Design

The Fairchild graphical layout system is a design tool for the layout and production of masks for large-scale integrated circuits. Its purpose is to reduce the time delay from the specification of a circuit design in schematic form to the production of a set of masks to be used in the manufacturing process. The system operates on an IBM 1130 computer with 16K 16-bit words of core memory. A Sanders display system built to Fairchild specifications makes possible rapid graphic man-machine interaction. An entire design may be carried out at the display or portions of it may be entered through punched cards. Final output consists of masks cut on a Calcomp plotter, line drawings, and/or digital images of the design which may be saved for later use and modification, or for output on other media (e.g., reticle generators). The use of a grid system for determining coordinate positions together with software windowing and scaling has produced a layout design package that is easy to use and provides rapid response to user requests with a relatively small low-speed computer. The graphical layout system produces circuit layouts with resolutions that are an order of magnitude greater than the resolution of the CRT display.