| 摘要 |
PURPOSE:To read various copying states by connecting an interface board to the RAM socket of a copying machine control board and enabling the transmission and reception of data, and using a dual-port RAM on an adapter side for a communicating means and sharing some addresses of the RAM. CONSTITUTION:The interface board is provided with pins so that it can be connected directly to the RAM socket of the main control board of the copying machine. A RAM which serves as the RAM on a main control board and a bus driver/receiver for interface with the RAM are mounted on the interface board. When A3-A10 are all H, the RAM on the interface board is inhibited from being accessed and switching to the dual-port RAM of a microcomputer on the adapter is performed. The high-order byte addresses of the RAm are assigned on the dual-port RAM. Then, the computer side transmits and receives data to and from the adapter as well as the reading and writing of the RAM. Consequently, a data communication can be made without altering the control board of the copying machine. |
