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Monochrome Display Driven by Color System

IP.com Disclosure Number: IPCOM000062298D
Original Publication Date: 1986-Nov-01
Included in the Prior Art Database: 2005-Mar-09

Publishing Venue

IBM

Related People

Authors:
Anwyl, ED Davis, MI [+details]

Abstract

A color display system generates a differential 8-level output from a digital-to-analog converter (DAC) for each of three colors. When using these three color outputs to drive a monochrome display, the outputs of two DACs are wired together to provide a differential 16-level monochrome grey scale drive signal. Alternatively, the outputs of three DACs are mixed by a matching impedance network to provide a 24-level monochrome drive signal. Fig. 1 shows a portion of a typical all-points-addressable (APA) display system. Eight bit planes are shown, each plane typically carrying one storage cell position for each picture element (pel) on the CRT screen. By the use of multiple bit planes, each pel can have a variable color assigned to it.