Personal computer with multiple independent CRT displays of ideographic and/or ASCII characters having loadable font memory for storing digital representations of subset or special characters
US4954979A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 22, 1985 |
| Grant date | Sep 4, 1990 |
| Priority date | — |
| Expiry date | Aug 22, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2360/04
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A plurality of language display control cards are provided for insertion into the motherboard of a personal computer, each card having connector means to which a CRT display and a keyboard may be connected. Each card controls its display independently of the others so that different data may be displayed on each display screen. A display control card includes a font memory for storing the digital video representations of ideographic characters of a standard code, and an ASCII memory for storing the digital video representations of ASCII characters. In addition a loadable font memory is provided for storing the digital video representations of characters which are not commonly used characters of a language but may be frequently used in a particular application. The outputs of the three memories may be serially interspersed so that the CRT may display ASCII, or ideographic characters or a mixture of both. To reduce the size of the font memory, a translator memory is provided for converting non-sequential numbers representing the characters of a standard internal code used by the PC into a sequence of consecutive numbers for addressing the font memory.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.