Abstract: A method and apparatus whereby an auxiliary yoke is used in conjunction with a CRT display to correctively deflect the electron beam to a true position within each pixel of a graphics figure, as the graphics figure is displayed on the CRT's screen. The apparatus thus increasing the display's resolution within each pixel so as to permit the smoothing of the displayed graphics figures.The improved resolution being achieved via a four bit binary position correction code, three bits of which are stored in the image memory at those memory addresses corresponding to the coordinates of the pixels that comprise the graphics figure, and one bit of which position correction code is stored at the immediately preceeding memory addresses. The entire position correction code in turn being decoded as the image memory is read and used to drive one or the other of the x and y coil pairs of the x-y auxiliary yoke.

Abstract: A system for expanding a dot-matrix for characters being displayed on a television raster scan display to improve the readability and resolution of displayed characters without a corresponding increase in the size of the Read-Only Memory (ROM) employed to generate the pattern of dots defining the characters. This result is accomplished by first displaying the identical dot-matrix stored in the ROM for each character in each row of characters to be displayed on the first pass of the raster scan. On the second pass of the raster scan, which is interlaced between the lines of the first pass of the raster scan, a new dot-matrix is inserted according to a predetermined logical real time comparison of the dot matrix of the adjacent rows of the dots produced during the first raster scan.

Abstract: A transmission line driver circuit especially designed for transmitting nonsymmetrical codes wherein signals to be transmitted are coupled to the lines by means of first and second transformers. A pair of digital logic circuits are connected to said first and second transformers such that positive going pulse signals are transmitted by way of the first transformer and negative going pulses are transmitted by way of the second transformer. Further circuitry is provided for discharging the energy stored in the magnetic field on the first transformer when the second transformer is coupling a pulse to the line and vice versa.