CALIBRATING OPTICAL DATA TRANSMISSION FREQUENCY FROM CRT

摘要

The invention includes systems and methods for calibrating bit transmission rates in a computer system (11) which uses selected raster lines ¢30(1)30(10)! of a frame-scanning display device (14) for serial data transmission to an external receiving device (12). A data processor (17) is programmed to count the number of timing signals (104) generated by an internal timer (24) and the number of frame scans (106) of the frame-scanning display device which occur during a selected measurement period. The data processor (17) is further programmed to calculate a frame scan period (109) of the frame-scanning display device based upon the predetermined frequency of the timing signals, the predetermined number of timing signals, and the number of frame scans counted while counting the predetermined number of timing signals. The frame scan frequency is used to determine (109, 110, 112) the correct spacing of the data transmission raster lines which establishes the desired serial transmission bit rate to the external receiving device.