Character display device for television monitor

Claim 1

A character display device for display on a television monitor having a plurality of picture lines comprising a buffer memory for storing a plurality of rows of characters, a circulating memory for storing a line of characters, said circulating memory including a plurality of circulating registers each storing a portion of said row of characters, a decoder coupled to said circulating registers, said decoder responsive to the output of said circulating registers for providing a signal for selecting a character, a character generator coupled to said decoder and responsive to said decoder signal for generating the selected character, said television monitor coupled to said character generator for displaying each selected character, a checking device coupled to said circulating memory for recirculating said character line for as many times in succession as there are picture lines per line of characters, said checking device including a picture line counter and a character line counter, said checking device further coupled to said buffer memory for transferring the next successive character line to said circulating memory during the time interval corresponding to the plurality of picture lines representative of the space between adjacent rows of characters, said buffer memory including an address control device coupled thereto, said picture line counter and said characters per line counter being coupled to said address control device for selecting addresses of characters, in a sequence independent of the sequence of characters in a line of the display, in said buffer memory, and means for circulating said circulation memory during the time of a space between lines for a period of a number of lines whereby after the last picture line of a space, the circulation memory is supplied with characters on a line in succession.