Abstract: The invention concerns storage of data within a computer, from which a composite image may be generated on the computer's display. The data may include different types, which are normally incompatible, such as particular types of RGB data, and particular types of YUV data. As a specific example, the invention allows a user to view the image generated by an ordinary computer program, such as a word-processing program; which uses RGB data, together with a movie stored on video tape, which may use YUV data. The movie appears in a small window on the display.

Abstract: In a computer system, a direct access, independently arbitrated video bus (connected to a personal computer (PC) -compatible video subsystem) is directly coupled to one or more dual-ported processors to eliminate video cycle traffic over the system bus or buses and I/O bus, thereby improving system performance. The preferred embodiment architecture has, in addition to the video bus, multiple processors coupled to at least two independently arbitrated system buses which are coupled to at least two independently arbitrated input/output (I/O) buses, to provide for rapid bus information signal transfer rates.

Abstract: The present invention discloses a method and apparatus for performing data compression during monitor refresh operations. In one embodiment, it is envisioned that the compression functions would be performed in a refresh compaction device and the de-compression functions would be performed in a RAMDAC, thereby requiring only the transfer of compressed data between the refresh compaction device and the RAMDAC. In an alternative embodiment, it is envisioned that both the compression and de-compression functions would be performed in the refresh compaction device. Regardless of implementation, a "critical fill" level is determined during compression and a "critical fill" interrupt is generated during de-compression to gain control of the frame buffer before the compressed digital data is fully depleted.