Color Electrostatic Printer

Michael Frank Deering: Hardware: Color Electrostatic Printer

Company: Benson

Year of Commercial Product Release: ~1986

Product Production Name:

The product was named “color electrostatic system”, or “CES” (which caused some marketing problems in France).


Both Versatec and Varian developed and sold narrow and wide body monochrome printers starting the mid nineteen seventies, generally printing square pixels at 200 dpi. By the early eighties, Versatec has a four color that worked by making four passes over the paper, and the company had been acquired by Xerox. Benson, which by then had been acquired by Schlumberger, was working on a four color single pass printer, with a rendering resolution of 400 dpi. The print engine development was coming along with the usual fits and starts, but the interface to feed such a high speed beast was becoming a problem. Customers were switching over from simple pen plotter languages (which had still been used to drive the raster devices) to more general graphics APIs, specifically Adobe’s PostScriptTM.

I, with Bill Graves and others, were given the challenge of coming up with a rasterizer that could work as fast as the printer, and because of time constraints, we had to use off the shelf chips. The solution we came up with was to use an array of 2D PC graphics chips to render different swaths of the image on the fly. Someone else came up with the idea of pre-scanning the input to check for “hot spots” where the chips might run slower than the printer; these very few areas were pre-rendered onto disk and output when their part of the paper came flying by.


Being the only single pass color wide body electrostatic plotter gave Benson a timely product for the VLSI industry (chips were still printed out on large wall drawings for additional checks), though eventually Xerox/Versatec came out with a competing product.

The market eventually went away as chips got too big to be worth printing (the last go was at Intel where they had a 20′x20′ room with the entire chip plot on the floor and the engineers had to wear slippers and crawl over their circuits to inspect them), and other markets liked the cheaper wide-body ink-jet plotters.