| 摘要 |
PURPOSE:To perform high speed transfer when character data is developed to a bit map memory, by providing an address magnifying circuit for magnifying an address twice and a bus driver for adding blank data before and behind character data. CONSTITUTION:When a blank is added in the longitudinal direction of a 24X24-dot character, six address bit lines A0-A5 are determined in order to display 64 addresses but the highest rank bit among them is neglected to employ an address system wherein two 32-addresses are present and character data 5 is written in a character generator ROM and a blank part 6 corresponding to 8 bits is formed by a bus driver. As mentioned above, if the blank part is provided and the address is magnified twice by an address magnifying circuit 7, blank parts can be formed above and below the character data 5. By this method, the character part of the character generator and the upper and lower blank parts before and behind said character part can be simultaneously transferred and high speed transfer can be performed.
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