Video display system

Claim 1

Apparatus for providing a visual display of first and second received sequences of characters represented by first and second received sequences of character signals comprising: timing generator means for generating a pre-determined number of timing signals; first and second input register means for storing and reading out the first and second received sequences of character signals, respectively; first and second transfer control means for sensing the number of received character signals present in said first and second input register means, respectively, and for generating first and second transfer control signals respectively indicative of the numbers of character signals present; first recirculating buffer means for storing a selected number of character signals read out of said first input register means and responsive to certain of the timing signals generated by said timing generator means and to said first transfer control signals for simultaneously reading out and restoring the character signals stored therein; second recirculating buffer means for storing a selected number of character signals read out of said second input register means and responsive to certain of the timing signals generated by said timing generator means and to said second transfer control signals for simultaneously reading out and restoring the character signals stored therein; gate means responsive to the readout of character signals from said recirculating buffer registers and to selected timing signals generated by said timing generator means for alternately transmitting to the character generator means the character signals read out from said first and second recirculating buffer registers; character generator means responsive to the character signals read out from said first and second recirculating buffer means for converting the character signals to an electrical array, the array forming the character represented by the character signals being read out; scanning means responsive to certain other timing signals generated by said timing generator means for scanning the array corresponding to the character being read out; image reproducing means responsive to the output of said scanning means for displaying the first and second sequences of characters in rows on a display screen, said image reproducing means including deflection means responsive to still other timing signals generated by said timing generator means for implementing line scanning in the first direction and field scanning in a second direction, the characters being sequentially presented on a display screen in rows which are oriented in the direction of field scanning; first offset counter means responsive to said first transfer control signals for controlling the initial scan of said array to thereby produce an incremental positioning in the reproduction of the first sequence of characters by said image reproducing means in accordance with the number of character signals present in said first input register means; and second offset counter means responsive to said second transfer control signals for controlling the initial scan of said array to thereby produce an incremental positioning in the reproduction of the second sequence of characters by said image reproducing means in accordance wIth the number of character signals present in said second input register means.