Browse Prior Art Database

Color on Color Character Attribute Mapping Implementation for a Liquid Crystal Display

IP.com Disclosure Number: IPCOM000061311D
Original Publication Date: 1986-Jul-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Arismendi, AA: AUTHOR [+4]

Abstract

A method is described to permit application programs utilizing the Personal Computer Color Graphics Adapter in the alphanumeric mode to display their text on a liquid crystal display for program transportability. The attribute byte of a given character defines its background and foreground colors. The bit positions are defined below (R is red, G is green, B is Blue, and IN is Intensify): (Image Omitted) A liquid crystal display (LCD) is limited to 2 colors: grey and black. In order to display color characters, mapping the attribute to allow it to be displayed on the LCD is done with a Color Enable Register and its associated logic. The Color Enable Register is defined as follows: (Image Omitted) Each of the color bits in the register correspond to the RGB bits of the character attribute.

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Color on Color Character Attribute Mapping Implementation for a Liquid Crystal Display

A method is described to permit application programs utilizing the Personal Computer Color Graphics Adapter in the alphanumeric mode to display their text on a liquid crystal display for program transportability. The attribute byte of a given character defines its background and foreground colors. The bit positions are defined below (R is red, G is green, B is Blue, and IN is Intensify):

(Image Omitted)

A liquid crystal display (LCD) is limited to 2 colors: grey and black. In order to display color characters, mapping the attribute to allow it to be displayed on the LCD is done with a Color Enable Register and its associated logic. The Color Enable Register is defined as follows:

(Image Omitted)

Each of the color bits in the register correspond to the RGB bits of the character attribute. When there is a "1" in a color position of the register, it will enable the corresponding foreground/background bit in the character attribute to produce an "ON" LCD pel. After the character attribute has been sifted through the Color Enable Register, the mapping of an enabled foreground color overlaying an enabled background color is as follows: - If the enabled foreground color is not the same as the enabled background color, the character is displayed in Reverse Video to allow its visibility and to distinguish it from characters with an enabled foreground color, but without an enabled backgr...