This disclosure relates to a digital video display system wherein a control element is provided that includes position and count registers to specify the initial position of a scan line and the number of scan lines displayed which registers are supplied with incoming data to specify the position of each...http://www.google.com/patents/US4284988?utm_source=gb-gplus-sharePatent US4284988 - Control means to provide slow scrolling positioning and spacing in a digital video display system
