14. A unit as defined in claim 13 wherein a group of lines that appear to be displayed simultaneously by said display means constitute a frame of text and wherein said address generating means includes a running address generator and means connecting said running address generator to said memory means, said unit additionally comprising a first display register connected to said address transfer means, said address transfer means loading the contents of said first display register into said running address generator prior to the beginning of each display frame whereby said display means repeatedly displays a string of characters beginning with the characters corresponding to the character codes stored in said memory means at the address indicated by said first display register.
13. A unit as defined in claim 12 wherein said transfer means includes a character register connected to said memory means for storing the succession of characters from said memory means and wherein: F. said margin means includes: i. margin register means for storing the predetermined number that establishes the number of display positions on the given line, ii. a character counter connected to said timing means and said margin register means that counts the character codes retrieved from said memory means, iii. comparison means connected to said margin register means and said character counter for indicating an equality when said margin register means and said character counter are equal, and I. said display position recording means includes a position recording register means connected to said delimiter means, said comparison means and said character counter for storing the contents of said character counter each time said delimiter means indicates the retrieval of a delimiter character from said memory means until said comparison means indicates equality whereby said position recording register means records the position of the last delimiter character for the given line, said control means being connected to said position recording register means to cause said transfer means to inhibit the display of characters corresponding to the character codes in said first register following the last delimiter character.