ocr: 4.3.2 SIGNAL DESCRIFTION ADDRESS BUS Pins 1 thru 3 and 36 thru 48 The 16 bit address bus is bidirectional. As an inputy the aicroprocessor can access any of the 34 TED control resisters In the outeut mode TED uses the addresses to fetch Video Matrix Pointersi Attribute Pointers or character cell infcraztion. For microprocessor interface TEI resides in locztions FFO0-FF3F in memory. DATA SUS Pins 25 thru 36 The 8 bit data bus is also bidirectional. The data bus Ectivity can be separated into 2 catesories: aicroFrocessor interface and video data interface durins the above mentioned fetches. KEYE ...
