| 摘要 |
PURPOSE:To secure the connection between a computer having no direct memory access function on an interface and a terminal equipment having a DMA function, by providing an input register which uses the output data of a computer as an input and has the output connected to the input data terminal of the terminal equipment. CONSTITUTION:An interface auxiliary device 1 receives a cycle request from a terminal equipment 3 and sets a busy FF 21 to set the busy signal applied to the equipment 3 at a high level. Then 1 is added to a word counter 16 with the cycle request. An FF 10 is set and the signal of a low level is applied to a switch circuit 4. The read/write request D.C sent from a computer 2 is inverted and applied to a AND circuit 11. The signal D.C is set at a low level as soon as the data is sent from the computer 2 and therefore the circuit 11 supplies an output. Then a monostable multivibrator 22 produces a 100ns pulse signal. This pulse signal is sent to an input register 7 as a control signal. Then the data given from the computer 2 is set to the register 7. The FF 21 is reset and at the same time an end cycle is sent to the equipment 3.
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