JPH06149718A - Switching system of input/output device - Google Patents

Abstract

PURPOSE:To perform maintenance operation such as a diagnosis of an input output device, etc., by an external computer and carry on operation in execution by the computer by disconnecting the input/ output device from a computer system through an electric circuit or logically and connecting it to the external computer system. CONSTITUTION:When a switch 9 is set in the ON state, a hard disk controller 10 which is actuated from an I/O port 4 can not access an internal hard disk device 7 since it is electrically disconnected by an access control circuit 8a. Even when the switch 9 is in the ON state, the external computer device 12 which is connected to a connector 11 can access the internal hard disk device 7. Consequently, the external computer 12 can carry on the maintenance operation such as a diagnosis of the hard disk device 7 and operation being executed by a CPUI by using a program and data recorded on the hard disk 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an input / output device switching system for accessing an input / output device incorporated in a computer system from an external computer system.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing a configuration of a conventional computer device disclosed in Japanese Patent Laid-Open No. 3-288223, in which 1 is a CPU, 2 is a ROM, and 3 is a ROM.
Is a RAM, 4 is an I / O port, 5 is a data bus, 6 is a keyboard, 7 is a built-in hard disk device, 8 is an access control circuit for controlling access to the built-in hard disk device, and 9 is a switch.

Next, the operation will be described. If the switch 9 is set to the OFF state, the access control circuit 8
Does not operate, the hard disk device 7 can be accessed via the I / O port 4. Also,
When the switch 9 is set to the ON state, the access control circuit 8 causes the hard disk device 7 via the I / O port 4 to operate.
Since it operates so as to inhibit access to the hard disk device 7, it becomes impossible to access the hard disk device 7.

[0004]

Since the conventional device is constructed as described above, it is possible to make the hard disk device inaccessible from the computer main body, but when an abnormality occurs in the computer. ,
It was not possible to access the hard disk device from an external computer to perform maintenance work such as diagnosis, or to continue the work being executed on the computer using the hard disk on the external computer.

The present invention has been made in order to solve the above problems, and an input / output device built in the main body of a computer system, in particular, a file device represented by a hard disk device or a flexible disk device is provided. By disconnecting the computer system electrically or logically so that it can be accessed from an external computer system, maintenance work such as diagnosis of the input / output device can be performed without stopping the computer system. The purpose is to do. Further, it is an object of the present invention to allow the work being executed in the computer system to be continued by using the file device from an external computer when there is no abnormality in the file device when a failure occurs in the computer system.

[0006]

An input / output device switching method according to the present invention comprises an access control circuit for electrically connecting / disconnecting an input / output control device and an interface signal for connecting the input / output device. A switch for controlling the access control circuit and a connecting means for connecting a signal for accessing the input / output device from an external computer are provided.

Further, receiving the interface signal,
An identification number conversion circuit for converting an identification number issued by the input / output control device according to the state of the switch, and a connection means for connecting a signal for accessing the input / output device from an external computer are provided.

Further, an access control circuit for electrically connecting / disconnecting the input / output control device and an interface signal for connecting the input / output device, and a connecting means for connecting a signal for accessing the input / output device from an external computer. With
By connecting the external computer to this connection means,
The access control circuit is controlled.

[0009]

In the input / output device switching system configured as described above, the input / output device incorporated in the computer system is electrically or logically separated from the computer system to allow access from an external computer. As a possibility, it becomes possible to use the external computer to continue maintenance work such as diagnosis of the input / output device and work being executed in the computer.

[0010]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is CPU, 2 is ROM, and 3 is R.
AM, 4 is an I / O port, 5 is a data bus, 6 is a keyboard, 7 is an internal hard disk device, 8 is an access control circuit, 9 is a switch, 10 is a hard disk control device, 11 is a connector, and 12 is an external computer device. is there.

When the switch 9 is set to the OFF state, the access control circuit 8a simply operates as a normal circuit, so that the hard disk control device 10 which is activated from the I / O port 4 operates as an internal hard disk device. Can be accessed as usual. Switch 9
Is set to the ON state, the access control circuit 8a is used when the hard disk control device 10 that has been activated from the I / O port 4 accesses the internal hard disk device 7.
It cannot be accessed because it is electrically separated by. Even when the switch 9 is in the ON state, the internal hard disk device 7 can be accessed from the external computer device 12 connected to the connector 11, so that the external computer device 12 diagnoses the hard disk device 7. It is possible to continue the work being executed by the CPU 1 by using the maintenance work and the programs and data recorded in the hard disk device 7.

Example 2. In FIG. 2, the access control circuit 8a of FIG. 1 is replaced with an identification number conversion circuit 13. When the switch 9 is set to the OFF state, the hard disk controller 10 (identified as identification number # 7) that has been activated from the I / O port 4 becomes the internal hard disk device 7 (identified as # 0). At the time of access, the identification number conversion circuit 13 does not operate and can be accessed. When the switch 9 is set to the ON state, I
When the hard disk controller 10 activated by the I / O port 4 accesses the internal hard disk device 7 (identification number 0), the identification number conversion circuit 13 monitors the control signal and outputs it as a data signal. To convert only the number, for example, to convert to the identification number 1,
It is in a logically separated state and cannot be accessed. Further, the identification number conversion circuit 13 has a switch 9
Even if is ON, no conversion is performed for access from the external computer device 12, so the switch 9
When the internal hard disk device 7 is accessed from the external computer device 12 connected to the connector 11 by turning on, the internal hard disk device 7 can be accessed by accessing with the identification number 0.

Embodiment 3. In FIG. 3, the switch 9 of FIG. 1 is included in the connector 11. Connector 1
When the external computer device 12 is connected to the HDD 1, the access control circuit 8a detects it, and when the hard disk control device 10 that is activated from the I / O port 4 accesses the internal hard disk device 7, the access control circuit 8a It cannot be accessed because it is separated from the electrical circuit. Further, since the internal hard disk device 7 can be accessed from the external computer device 12 connected to the connector 11, maintenance or the like can be performed.

Example 4. Further, the access control circuit shown in the first embodiment can be configured as shown in FIG. With this configuration, the connector 11 can be kept connected to the external computer 12 at all times. The identification number conversion circuit 13 shown in the second embodiment can incorporate the same idea.

Example 5. In the above embodiment, the internal hard disk device is logically separated by using the identification number conversion circuit in FIG. Equivalent functions can be realized.

In the above embodiment, the hard disk device is shown as the input / output device, but it goes without saying that the invention can be applied to a file device such as a flexible disk device or a cartridge MT device, or other input / output device built in the main body.

[0017]

As described above, according to the present invention, the input / output device incorporated in the computer system can be electrically or logically separated from the computer system and connected to an external computer system. Therefore, when an abnormality occurs in the computer system, maintenance work such as diagnosis of the input / output device or continuation of work being executed in the computer system can be performed using an external computer system. .

[Brief description of drawings]

FIG. 1 is a block diagram showing a switching system of an input / output device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an input / output device switching method according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing an input / output device switching system according to a third embodiment of the present invention.

FIG. 4 is a block diagram showing an input / output device switching method according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram of a conventional example.

[Explanation of symbols]

 4 I / O Port 7 Built-in Hard Disk Device 8a Access Control Circuit 8b Access Control Circuit 9 Switch 10 Hard Disk Control Device 11 Connector 12 External Computer Device 13 Identification Number Conversion Circuit

Claims (3)

[Claims] 1. A computer system in which an input / output device is built in a main body, and an access control circuit for electrically disconnecting the input / output device from the computer system,
The access control circuit comprises a switch and a means for connecting to an external computer system, and the access control circuit disconnects / connects an interface signal between the input / output control device controlling the input / output device and the input / output device according to the state of the switch, A switching system of an input / output device, wherein a signal line for operating the input / output device is connected to the connecting means for connecting to the external computer system. 2. A computer system having an input / output device built in a main body, comprising: an identification number conversion circuit, a switch, and means for connecting to an external computer system to logically disconnect the input / output device from the computer system. The identification number conversion circuit receives an input / output control device for controlling the input / output device and an interface signal between the input / output device and an identification number for the input / output device from the control device according to a state of the switch. The input / output device switching method, wherein the signal line for performing the conversion / non-conversion of the above-mentioned and operating the input / output device is connected to the connecting means for connecting to the external computer system. 3. A computer system in which an input / output device is built in a main body, and an access control circuit for electrically disconnecting the input / output device from the computer system,
The access control circuit is provided with means for connecting to an external computer system, and the access control circuit controls an interface signal between the input / output device controlling the input / output device and the input / output device to the connecting means depending on whether or not the external computer system is connected. A switching system of an input / output device, wherein a signal line for disconnecting / connecting and operating the input / output device is connected to the connecting means for connecting to the external computer system.