| 摘要 |
<p>A control apparatus for displaying alphanumeric characters on a cathode ray tube in a plurality of lines of n characters each, said apparatus comprising a character counter for counting the character positions along each display line and a character address register for storing the succeeding addresses of the locations in a memory containing the characters to be displayed, first means connected at the outputs from the character counter for detecting the address of character position k, where k is lower than n, and producing a stop signal for the counter when the latter reaches a count of k, the first means being arranged for holding the stop signal during a predetermined time equal to the scanning time corresponding to at least one character width, and second means connected at the outputs from the character counter for detecting the address of character position (k+1) and producing an inhibit signal during the occurrence of the stop signal. The inhibit signal serves to inhibit the illumination of the spot on the cathode ray tube thereby to prevent a same character to be displayed repeatedly while the character counter is stopped. Comparator means are coupled to the outputs from the character counter and the character address register for producing an illumination enable signal in response thereto.</p> |
