PC with multiple video-display refresh-rate configurations using active and default registers
US6049316A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 12, 1997 |
| Grant date | Apr 11, 2000 |
| Priority date | — |
| Expiry date | Jun 12, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2370/047
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A portable personal computer (PC) can be connected to a variety of different external CRT monitors. Configuration of each CRT monitor is performed by the graphics display driver software so that the user does not have to re-configure the graphics sub-system every time a different CRT monitor is connected. Auto-configuration of Plug-and-Play monitors occurs by reading configuration information from the monitor itself. For Windows 95, the Plug-and-Play drivers are used for auto-configuration, or for older operating systems the video BIOS display-data-channel functions is used. Older "legacy" CRT monitors that do not support Plug-and-Play are still auto-configured. The vertical refresh rate for each resolution is stored in a default register on the graphics controller chip. The vertical refresh rate from default register is copied to an active refresh-rate register when a legacy (non Plug-and-Play) monitor is detected. When a Plug-and-Play monitor is detected, the refresh rate is calculated and written to the active refresh-rate register, without overwriting the default registers. Thus a Plug-and-Play monitor can be connected without losing configuration information for the legacy mon…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.