Fujitsu Corporation

Hiroshi Minoura

Shoji Yamaguchi

An object of the present invention is to realize a palette control circuit which generates inconspicuous noise using simple circuitry and without reducing processing efficiency. A palette control circuit comprises a palette 5 used for color conversion, a selector 4 that is connected to the address input of the palette and selects image memory output or address data for use in accessing the palette, a holding circuit 6 for temporarily holding the output of the palette 5, and a control circuit 7 for issuing an input select instruction to the selector 4, access control signals to the palette 5, and a data holding instruction to the holding circuit 6. For displaying normal image memory, the control circuit 7 instructs the selector 4 to select image memory output and allows the holding circuit 6 to pass palette output as it is. For accessing the contents of the palette, the control circuit 7 instructs the holding circuit 6 to hold the preceding output of the palette 5 and allows the selector 4 to select address data for use in accessing the palette.

Palette control circuit

A data processing system, which includes a CD-ROM drive, addresses data in a CD-ROM and commands the CD-ROM drive to read the data. The data processing system selects one of a plurality of control programs corresponding to a format of the data in the CD-ROM used, and controls the CD-ROM drive to read the data addressed by using the control programs. Further, the data processing system processes the data read in a accordance with the data format and stores the data processed in a memory.

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Kawasaki, Japan

Hiroshi Minoura