The design and construction of a low cost visual display unit

Abstract

After discussing the techniques employed in alpha-numeric V.D.U.s, and the style of storage used in map displays, the thesis goes on to describe & screen addressing system. This addressing system allows the display of detailed and varied designs on a raster-scan display, without recourse to the large stores required to implement the map technique. The addressing technique is used in a simple V.D.U, which, in order to minimise costs, uses a domestic television monitor as an output device. The display refresh store is made up of M.O.S. shift registers, and the store contents are organised under micro processor control. Though the unit described is primarily designed for the display of circuit diagrams it is easily adapted to the display of a wide range of graphic formats.