PERIPHERAL DEVICE CONTROLLERS

This chapter discusses different peripheral device controllers. Visual display systems for use with microcomputers make use of video techniques where the text, or graphics, data are presented on a raster scan display similar to that used for television pictures. The Motorola MC6845 is a CRT display controller that provides the control and timing logic for a VDU, but it requires an external character generator ROM, screen refresh memory, and video signal circuits. The Motorola MC6847 video display generator provides a complete video display controller for both text and graphics type displays. The Thomson EFCIS 96364 is a video display controller that provides the display logic and timing for a text display on a television screen. It may be used with any type of microprocessor system using an 8-bit data bus. The floppy disk controller storage medium is a flexible plastic disk coated on one or both sides with a magnetic oxide and is enclosed in a cardboard or plastic envelope for protection.