The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 23, 1989
Filed:
Aug. 13, 1984
David J Gover, Eastleigh, GB;
Adrian J Hawes, Eastleigh, GB;
International Business Machines Corporation, Armonk, NY (US);
Abstract
A raster-scanned interlaced cathode ray tube display is refreshed from a bit buffer (1). Cursor control logic (17) compares the refresh address (3, 4) with a desired cursor address and generates cursor defining bit patterns in synchronism with the bit pattern derived from the bit buffer (1). The cursor control logic (17) also generates overlay information (25) to control the mixing of the bit streams in mixers (11, 12, 13) to produce a 2 or 3-pel wide cross-hair cursor on the CRT screen. The cursor lines can be black, white or transparent. The overlay signal may also be used to control a further optional mixer combining the composite cursor bit-buffer bit patterns with bit patterns derived from a coded character buffer containing coded alphanumeric characters to be displayed.