Abstract: A time variant measured variable is graphically displayed in moving strip chart format on a cathode ray tube. During a scan line the electron beam is intensity modulated at a position on the scan line whith represents the magnitude of the measured variable at a given time. The intensity of the electron beam at positions in successive scan lines is similarly intensitymodulated to produce a trend line representing the magnitude of the variable along the strip chart format. During the scanning of a subsequent raster frame, a new data value of the measured variable is displayed at a selected position at an edge of the viewing area of the strip chart format in thwe location previously occupied by the next sequential value and the older data values are simultaneously displaced. The oldest data value is deleted from the format. During a raster scan the electron beam is modulated at different intensity levels to produce chart lines and time lines on the strip chart format.