Video board for serving both 1-bit plane operation and 2-bit plane operation

A video board circuit having a one-bit plane video board mode and a two-bit plane video board mode, said video board circuit comprising:

• processor means for controlling operation of the video board circuit in dependence upon computer control signals of a computer;
• means for storing picture information in dependence upon processor control signals of said processor means;
• switching means for providing switching output by separately buffering said picture information from said storing means into first and second parts each having an equal number of bits, said first part comprising high order bits and said second part comprising low order bits;
• and
• video output controlling means for selectively generating video output signals for the one-bit plane video board mode and the two-bit plane video board mode by shifting said switching output from said switching means in accordance with a selection signal corresponding to selection of one of the one-bit plane video board mode and the two-bit plane video board mode.

A process for controlling a video board, comprising the steps of:

• controlling storage in a memory of video information in dependence upon processor control signals of a processor stage;
• transmitting said video information as eight-bit bytes from said memory to a video output controlling stage;
• generating video output signals in the video output controlling stage for one of a one-bit plane video board mode and a two-bit plane video board mode by shifting said video information transmitted to said video output controlling stage in response to a selection signal;
• and
• displaying said video output signals.

A video board circuit supporting a one-bit plane video board mode for generating video data and a multi-bit plane video board mode for generating gray level video data, said video board circuit comprising:

• memory means for storing received video data from a host interface, and for reading out said received video data as parallel video data in response to memory control signals;
• graphic processor means for controlling storage of said received video data in said memory means, and for generating said memory control signals;
• switch means for receiving said parallel video data in sixteen parallel bits, for converting said parallel video data to eight parallel bits, and for providing said parallel video data of said eight parallel bits;
• and
• video output controlling means for receiving said parallel video data of said eight parallel bits, for generating one-bit plane video data by converting said parallel video data of said eight parallel bits to a single bit serial format, and for generating multi-bit plane video data by converting said parallel video data of said eight parallel bits to a multi-bit serial format.

A video board circuit supporting a one-bit plane video board mode for generating video data and a multi-bit plane video board mode for generating gray level video data, said video board circuit comprising:

• memory means for storing received video data from a host interface, and for reading out said received video data as parallel video data in response to memory control signals;
• graphic processor means for controlling storage of said received video data in said memory means, and for generating said memory control signals;
• and
• video output controlling means for receiving said parallel video data, for generating one-bit plane video data by converting said parallel video data to a single bit serial format, and for generating multi-bit plane video data by converting said parallel video data to a multi-bit serial format, said video output controlling means comprising:
• shift register means for receiving said parallel video data at a plurality of input terminals, for transferring said parallel video data to a plurality of output terminals in response to selection signals received at a selection line, and for shifting said parallel video data at said output terminals in response to clock pulses to generate one of said one-bit plane video data and said multi-bit plane video data.

A video board circuit supporting a one-bit plane video board mode for generating video data and a two-bit plane video board mode for generating gray level video data, said video board circuit comprising:

• memory means for storing received video data from a host interface, and for reading out said received video data as parallel video data in response to memory control signals;
• graphic processor means for controlling storage of said received video data in said memory means, and for generating said memory control signals;
• and
• video output controlling means for receiving said parallel video data, for generating one-bit plane video data by converting said parallel video data to a single bit serial format, and for generating two-bit plane video data by converting said parallel video data to a two-bit serial format.