Patent · US Expired

Apparatus and method for data entry and display

US4068226A · kind A · utility

5Cited by
7References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 10, 1975
Grant dateJan 10, 1978
Priority date
Expiry dateJun 10, 1995

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG09G3/04
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

Data entered at a matrix keyboard or from a remote computer is loaded into a display buffer area of a random access storage device. Data is displayed by sequentially refreshing a plurality of display elements from a one character display buffer, loaded from the storage device under control of a display address counter. Data storage and data retrieval for display is multiplexed, with data retrieval being synchronous with respect to a system clock, and data loading being asynchronous from the keyboard. A control counter, synchronously driven by the system clock, is decoded to scan the keyboard for data entry and to gate the one character display buffer to the next sequential display element to be refreshed. Initial correspondence between the display gating and the display address counter is established, which correspondence is asynchronously stepped by entry of another character from the keyboard, so that the most recently entered character appears at the rightmost position of the display.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.