摘要 |
The prolonged depression of a cursor scan control key on a CRT terminal keyboard generates a unique coded signal that is fed to a gating circuit. Prolonged depression is further detected by an astable circuit that generates repeated enabling pulses to the gating circuit so that the coded signal is repeatedly transferred to a separate programmable control unit. The unit is programmed to translate the repeated signals to a cursor scan command for a CRT which forms a part of the terminal.
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