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United States Patent | 4,555,772 |
Stephens | November 26, 1985 |
A personal computer having an interactive all points addressable display terminal (44) and a cursor positioning device (52) and provided with apparatus for facilitating the generation of a graphics display using cursor characters selected from a table of cursor characters is capable of clearly demarking the currently selected cursor character from characters previously fixed at various points on the all points addressable display. This is accomplished by exclusive ORing the selected cursor character data with the corresponding data in the all points addressable display at the current position of the selected cursor character.
Inventors: | Stephens; Lawrence K. (Charlottesville, VA) |
Assignee: |
International Business Machines Corp.
(Armonk,
NY)
|
Appl. No.: | 06/499,452 |
Filed: | May 31, 1983 |
Current U.S. Class: | 715/856 ; 715/256; 715/259; 715/859; 715/866 |
Current International Class: | G09G 5/40 (20060101); G09G 5/08 (20060101); G06F 009/00 () |
Field of Search: | 364/2MSFile,9MSFile |
4200913 | April 1980 | Kuhar et al. |
4204208 | May 1980 | McCarthy et al. |
4298957 | November 1981 | Duvall et al. |
4377852 | March 1983 | Thompson |
4405978 | September 1983 | Lange et al. |
4471465 | September 1984 | Mayer et al. |