A digital generator for pattern drawing applications

The generator may be used off-line or on-line to a computer. It is used principally for integrated-circuit mask generation but is also suitable for other precision pattern-drawing applications. The generator accepts commands to draw line segments, to outline or scan rectangles, and to replicate patterns in regular arrays (step-and-repeat). The output of the generator comprises x and y co-ordinate-direction pulses. The organization of the instrument allows the later addition of other pattern modules. The instrument is constructed from off-the-shelf TTL. The advantage of the generator, compared to earlier models, is the great economy it effects with respect to the bulk of input-data medium or to the density of data on the computer interface line.