Abstract: A visual output assembly connects to a bus in a data processing system. The assembly includes a memory, plural visual display units and a multiplexing unit that connects to the bus, the memory and each visual display unit. Priority arbitration circuitry in the multiplexing unit receives request signals for access to the memory from the bus and from each of the visual display units. The priority arbitration circuitry controls address and data path switching circuits to establish appropriate address and data paths between the memory and the selected one of the bus and visual display units.

Abstract: A text-editing system includes a central processor unit, a bus connected to the central processor unit and input terminals connected to the bus for entering text and editing commands into the system. Text is displayed by the system on visual display apparatuses that are associated with each input terminal based upon information that is stored in display memories. A multiplexer circuit connects plural visual display apparatuses to the bus and a display memory and routes address and data signals between the display memory and either the bus or selected ones of the visual display apparatuses.

Abstract: A display unit useful for displaying graphical information and specifically for composing items to be printed on a page. The display unit includes a dot matrix screen and a display memory for storing the information to be displayed. An addressing register identifies memory locations in a sequence starting at location established by a begin display register. The starting location is transferred to the addressing register each time the display unit reaches a first dot location in the display unit. If the starting location is changed, an image corresponding to the item stored in the memory moves on the screen as a unit. Two or more memories can be interconnected to enable a relative motion between images corresponding to the items stored in each display memory.

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.

Abstract: A natural language text editing and display system having a central processing unit, a memory unit, and an input keyboard terminal. Display characters are selectively inserted into the text stored in the memory unit by actuating an insert key at the keyboard, positioning a cursor at the desired location on the display and actuating a key corresponding to a character to be inserted at that location. The terminal generates a character word having a character code corresponding to the selected display character and an insert code. The insert code identifies the associated character word as one to be inserted by the processing unit at the cursor location.