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Alphanumeric Graphic Display

IP.com Disclosure Number: IPCOM000091894D
Original Publication Date: 1968-Jun-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Kronick, HE: AUTHOR

Abstract

A cathode ray tube display is used in a system for alphanumeric and graphic displays. A single, efficient memory format is employed. For a 64 alphanumeric character capability, eight binary coded bits are used, six bits to identify the character, one bit to distinguish between control and data words, and a parity bit for checking. A character generator decodes the six-bit BCD information and generates the stroke format required to define the selected characters. For graphic information, a series of plotting characters, each comprising two columns of four dots, are arranged and uniformly spaced side-to-side and top-to-bottom in the form of a dot matrix pattern.

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Alphanumeric Graphic Display

A cathode ray tube display is used in a system for alphanumeric and graphic displays. A single, efficient memory format is employed. For a 64 alphanumeric character capability, eight binary coded bits are used, six bits to identify the character, one bit to distinguish between control and data words, and a parity bit for checking. A character generator decodes the six-bit BCD information and generates the stroke format required to define the selected characters. For graphic information, a series of plotting characters, each comprising two columns of four dots, are arranged and uniformly spaced side-to-side and top-to-bottom in the form of a dot matrix pattern.

Since the plotting character comprises eight dots, it can be identified by eight binary bits, each bit representing an intensity signal which is either on or off. This permits use of a mapped memory buffer in which each alphanumeric or plotting character on the cathode ray tube has an assigned memory slot corresponding to its position on the display. In the graphic mode, the plotting characters are generated individually in a zig-zag sequence bottom-to-top in row 1, top-to- bottom in row 2, etc., the characters being generated line-by-line in a typewriter mode. Various graphic patterns can be displayed by utilizing a plurality of plotting characters such as shown in the upper right quadrant in the drawing and selectively unblanking the beam at specified dots. The plotting charac...