Browse Prior Art Database

Minimizing Redisplay Alphanumeric Flicker

IP.com Disclosure Number: IPCOM000034555D
Original Publication Date: 1989-Mar-01
Included in the Prior Art Database: 2005-Jan-27

Publishing Venue

IBM

Related People

Authors:
Clegg, J Downs, T Whittingham, T [+details]

Abstract

This article describes an efficient method of eliminating alphanumeric flicker on displays which do not provide direct access to the bit planes. The method introduced involves the use of an extra attribute bit in a character representation as well as buffer update and display algorithms using this bit. Background displays supporting alphanumerics often require to make small changes to a large amount of text already displayed. On a display which does not allow direct access to the bit planes, it is often necessary for the sake of efficiency to request the hardware to update a larger area of the screen than is required. To update on a single character basis would usually prove too slow. On many devices when such an update is initiated, characters which are redisplayed but unchanged are seen to 'flicker' by the user.