General Electric Company

John C Sicko

Edwin C Underkoffler

John T Adamchick

A microcomputer controller for a printer, and apparatus for facilitating direct memory access to the microcomputer, includes a central processing unit (CPU) with a known set-up time at the beginning of each machine cycle. A memory, associated with the CPU, has an access time less than the CPU set-up time. A pair of three-state buffers are utilized on the address bus to, and the data bus to and from, the memory from each of the CPU and a direct memory access (DMA) port. A DMA control circuit is coupled to the three-state buffers to facilitate direct access to the memory, from the DMA port, during CPU set-up time intervals and also returns control of memory access to the CPU when the set-up, or synchronization, time interval ends. The microcomputer controller is utilized with additional memory, of the read-only type, and shift registers for realizing a printer controller capable of receiving print character data from the DMA port and causing that data to be printed as the associated symbol, indicia and the like, in a print font selected responsive to incoming data.

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Schenectady, NY, United States of America

John C Sicko