| 摘要 |
<p>The ball game generating unit, for a television receiver, allows either tennis or football to be played on a television screen. The line and frame sync pulses are generated by two counters: the first counting clock pulses and the second counting line pulses. The 'ball' consists of a video signal generated by a further two counters: one determing the ball's horizontal position by counting a variable number of clock pulses, and the other determining its vertical position by counting a variable number of horizontal sync. pulses. The ball counters are controlled by devices that determines the direction of motion of the ball.</p> |
