| 摘要 |
PURPOSE:To prevent almost an access time in the longitudinal direction for a RAM from changing from an aceess time in the horizontal direction and to realize a history map type image memory by word editing with a simple constitution by providing an address switching device, an adder means, right and left shifting means, etc. CONSTITUTION:The same number of RAM1-0-1-7 as the word bit of the image memory is provided, and RAM1-0-1-7 are simultaneously accessed by an address converting control signal 7. In accordance with the signal 7, lower-order bits 0-7 of logical addesses a and 4 are replaced with prescribed bits of higher- order bits 11.18 by an address switching device 5, and at the time of the longitudinal direction access indication, added to RAM1-0-1-7. Address adders 6-0-6-7 add a constant value to the bits 8-9 of an intermediate address 3. In accordance with the row position to be accessed, for the word data stored and read to RAM1-0-1-7, a prescribed quantity circulating shifting and an access time in the horizontal direction will not be changed by right and left shifting circuits.
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