Partitioned display control system
US4129858A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 23, 1977 |
| Grant date | Dec 12, 1978 |
| Priority date | — |
| Expiry date | Mar 23, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/04842
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A system for controlling display of characters on partitioned regions of a CRT display surface comprising a refresh memory having a capacity enough to store application display data for exhibiting application display on the entire area of the CRT display surface, and a special display data memory storing special display data for exhibiting special display on a limited specific region, for example, the lowest and second lowest display line portions of the CRT display surface to be pointed by a light pen. In the system, elements including a data selector, a comparator, a register and a flip-flop are provided to switch over the data input to the CRT unit so that, when the special display is not required, the data stored in the refresh memory are solely read out to exhibit the application display on the entire area of the CRT display surface, while when the special display is required, the data stored in the special display data memory are read out to exhibit the special display on the specific display region during scanning of this specific display region of the CRT display surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.