VIDEO DISPLAY TERMINAL WITH PARTITIONED SCREEN

A data display terminal includes a mapped character buffer (18) in which character bytes representing characters to be displayed on a CRT screen (23) are stored. Data streams from a host processor or data from a keyboard (12) are entered into the character buffer (18) by means of a microprocessor (7...

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Bibliographic Details
Main Authors HUGHES, MICHAEL A, JOHNSON, JEREMY S.M, WINN, GRAHAM C.E
Format Patent
LanguageEnglish
French
Published 22.06.1982
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Summary:A data display terminal includes a mapped character buffer (18) in which character bytes representing characters to be displayed on a CRT screen (23) are stored. Data streams from a host processor or data from a keyboard (12) are entered into the character buffer (18) by means of a microprocessor (7) having a data bus (8) and address bus (9). Refresh hardware including refresh logic control (19), line buffer (20, 28), character generator (21, 29) and serializer (22) write data within the buffer (18) to the CRT screen (23). Data integrity within partitions on the screen is maintained by employing left hand margin attributes for each partition. Efficiency is raised by employing right hand margin attributes. This requires slightly more character buffer space but allows the display to handle existing data streams.
Bibliography:Application Number: CA19790334068