公开(公告)号：US3812485A

公开(公告)日：1974-05-21

申请号：US25106672

申请日：1972-05-08

Applicant: INT COMPUTERS LTD

Inventor： MORETON D

IPC: G09G1/10 ,  G06F3/14

CPC classification number: G09G1/10

Abstract: A visual display device is described for drawing lines on the face of a cathode ray tube. Information describing the lines to be drawn is held in a store and is presented in the form of positional information describing one end (the initial end) of a line together with values representing the displacement from the initial end of the terminal end of the line. By relative shifting operations on this information a standardised line drawing speed is achieved by the repeated cyclic addition of the shifted displacement values into a register holding the positional and displacement information. Other relative shifting of positional and displacement information permits effective speeding up of ''''drawing'''' any part of a line that disappears off the field of view of the cathode ray tube and the shifting of both position and displacement values enables the scale of the drawn display to be altered.