Video display generator having alternate display modes

摘要

Video control circuitry for controlling the video format presented to the cathode ray tube to provide a combination of character generation and cell generation along with selective character inversion on a character-by-character basis. The video controller may comprise a video memory means for storing video character codes, character generator means and cell generator means both being coupled from the output of the video memory means in a common to a shift register. The shift register has associated therewith controls for the loading thereof and for the shifting of signals therefrom. Control signal means are provided having a video inverting and a video non-inverting state. At the output of the shift register, there is preferably provided output gating means. The aforementioned control signals couple to the output gating means for providing either inversion or non-inversion of the signal to the output gating means from the shift register. Depending upon the state of the control signal, the character information is either inverted or not inverted.