New Graphics Controller for Electrostatic Plotting

Recent developments in electrostatic plotting techonology-specifically in areas related to the plotter's speed, density, and color-forced processing requirements for graphics controllers beyond what is possible with traditional approaches. New market segments in the VLSI field, which were opened by the introduction of color, created more demanding applications, exceeding 10 million graphic elements per single E-size drawing. Conventional technology and architecture cannot generate the performance requirements within the given cost constraints. The new RPM (Raster Processing Machine) controller is based on a unique modular pipeline architecture, VLSI implementation of rasterizing routines, and parallel processing for performance and bottleneck by passing. For simple plots a single board processor based on the Motorola 68000 provides conversion from random graphic elements to the raster form required. As plot complexity increases, a special bipolar processor with a writable control store is added. For applications covering large graphic constructs with special texture (often needed for color generation), two custom chips on a dedicated VLSI board are added to the system. Multiplicity of processors and buses is possible for additional throughput. The controller's performance, along with the analysis of potential constraints, is also described.