| 摘要 |
In a computer system, a system video adapter and an add-on video adapter generate video signals according to different dimensional characteristics. The dimensional characteristics of the system adapter are calibrated by a calibration unit so that the video signals can simply be merged. The calibration unit comprises a comparator for detecting pixel signals of calibration lines generated by the system adapter at predetermined horizontal and vertical positions of a display device. The comparator, in response to detecting the pixel signals exceeding a predetermined reference signal, cause a latch to store counts of a counter. The counts represent the horizontal and vertical positions of the detected signals. The counts are presented to the add-on video adapter as calibration parameters. The add-on video adapter can use the calibration parameters to generate video signals which can be directly merged with the video signals of the system video adapter.
|
