Abstract

A text-editing and display system for editing and displaying natural language text, the system including a display controller, a central processing unit, a memory unit, a CRT raster scan display unit, and an input unit such as a teletypewriter keyboard. Text characters defining words are stored close-packed and in sequence in the memory unit except for the inclusion, where desired, of justification characters used for subsequent typesetting operations. The display is divided into a fixed header field and a text field. The display controller receives the memory addresses of the first characters of the header and text fields and a selected margin size. It retrieves the lines of text within each field from the memory unit and displays them within the selected margins. It calculates the memory address of the first character of each display line subsequent to the first line in that field. In addition, the display controller modifies the display appearance of any selected character to provide such features as black on white, blinking or underlined characters in response to appropriate coding data contained in each character word.