JPS6324755U - - Google Patents

Description

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of this invention, FIG. 2 is a block diagram showing a conventional device, and FIG. 3 is a block diagram showing another embodiment of this invention. 1 is a fixed disk device, 2 is a fixed disk control circuit, 3 and 8 are instruction signal lines, 4 is a CPU, 6 is a switch, 7 is an OR gate, and 9 is a flip-flop. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims for Utility Model Registration] A fixed disk that controls writing and reading to a fixed disk device that is capable of writing and reading data and retaining the written data even when the power is turned off. In the control device, an instruction signal line for sending a data write instruction signal from the fixed disk control circuit to the fixed disk device is cut in the middle, and the line on the fixed disk control circuit side is connected to the first input of the logic gate. , means for connecting the line on the fixed disk device side to the output of the logic gate; connecting a control signal line capable of inverting the signal logic on the line to the second input of the logic gate; When setting a signal to a first logic, the output logic of the logic gate is determined by the logic of the first input, and when setting a signal on the control signal line to a second logic, the output logic of the logic gate is determined by the logic of the first input. A fixed disk control device comprising: means for controlling the output logic to be a logic that prohibits signal writing to the fixed disk device, regardless of the logic of the first input.