Multicolor display from monochrome or multicolor control unit

Abstract

A preconverged color display station is disclosed which is compatible with a computer controlled control unit that provides electrical convergence control signals. Compatibility is obtained by causing the control unit to transmit the electrical convergence signals to the screen storage memory RAM (random access memory) which normally stores information defining the character and character attributes to be visually provided by the display station CRT screen. The stored convergence signals are read back to the control unit from the screen RAM. After all of the convergence signals have been received by the display station and prior to the transmission of character and character attribute information signals to the screen RAM, the contents of the screen RAM is erased. Subsequently, the contents of the screen RAM, which now contains character display information signals, is read out and utilized to define a visual display on a CRT. During the time that the screen RAM contains electrical convergence signals, the video of the CRT is blanked. Selection of any of at least three basic colors is provided by the color display station whether or not electrical convergence control signals are provided thereto and whether or not a monochrome or multicolor control unit is coupled thereto.

Dependencies are inferred from the claim text.