Abstract: A data display control arrangement in which apparatus for scrolling lines of data relative to a display area of a data display apparatus (1) comprises means (2) for producing a selectively controllable scrolling action, the means (2) including a transducer device (16) comprising two groups (18A, 18B) respectively including two sets (20,21) (24,25) of elctrical contact tracks 19 and an elastomeric pad which includes a non conductive member 27 is loaded with conductive material, whereby pressure on the member (27) changes the conductivity thereof and in so doing progressively interconnects the tracks of the sets (20,21) (24,25) to produce analogue signals related to extent of pressure. A converter 9 converts the analogue signals to digital signals which are used to control said scrolling.

Abstract: A visual display system having a restricted data display capability incorporating a main buffer store (1) having a storage capacity for data lines greater than the display line capacity of the display (2). Status information signals from a control unit 14 are associated with each line of data as it is introduced into the display so that when the display is scrolled or racked to free data display lines for new data--the status signal effectively decides whether a line of data is discarded or fed into the main buffer store (1).