JPH04343155A - Computer system - Google Patents

Abstract

PURPOSE:To confirm the condition of an access in more detail by providing a displaying means to perform the displaying corresponding to a command fetched by a command fetching means. CONSTITUTION:When the action condition of a computer system is moved to a command phase, a control data signal and a request signal are transmitted from a target to an initiator. The command data are transmitted from the initiator to the target. An address counter 3 outputs the address to write the command data, to a command buffer 4 and writes the data. Further, in a single chip microcomputer 20, a CPU 10 reads the target block address information from the command buffer 4, and the displaying is performed at a display lamp 11 by the light-up pattern corresponding to this. Then, an action abnormality can be detected and the quantity can be visually grasped.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a computer system using peripheral devices such as magnetic disk drives.

0002

[Prior Art] SCSI (Small Compute) is used as a peripheral device interface for small computers.
r System Interface) or SASI (Shugar System Interface) defined by Shugart.
t Associates System Inter
face) is known. As a system based on this type of interface, as shown in FIG. 4, a system in which a host computer 4a and a plurality of peripheral devices including a magnetic disk device 4b are connected via a SCSI bus is known. In this system, a device such as the host computer 4a that issues a command is called an "initiator", and a device such as the magnetic disk drive 4b that executes a command given by the initiator is called a "target".

In this type of system, the operator may need to know the access status of the magnetic disk drive 4b. Therefore, the access state in the magnetic disk device 4b has conventionally been displayed using the configuration shown in FIG. 5 or 6. First, the configuration shown in FIG.
An access lamp 5b is connected to a disk drive 5a in the target. According to this configuration, when the initiator accesses the target magnetic disk device 4b, the access lamp 5
b is lit.

Next, the configuration shown in FIG. 6 has a BSY (Busy) signal line 6a, which is one of the control buses in SCSI.
An access lamp 6b is connected to the access lamp 6b. In this configuration, when the initiator enters the selection phase to select a target, the LO is applied to the BSY signal line 6a.
A W level signal is output, and as a result, the access lamp 5b is lit.

[0005]

[Problems to be Solved by the Invention] However, the above-mentioned prior art has the following problems. First, in the case of the configuration shown in FIG. 5, there is a problem in that the operator only knows whether or not there is access to peripheral devices such as individual magnetic disk devices connected to the bus. Also, Figure 6
In the case of the configuration shown in , the access lamp 6b is turned on based on the signal on the BSY signal line 6a no matter which target is accessed. Therefore, there is a problem in that the operator does not know which target is being selected and accessed. In addition, even when using either of the configurations shown in FIGS. 5 and 6, the problem is that the operator can only know whether or not a peripheral device is being accessed, and cannot know more detailed access status. was there.

The present invention was made against this background, and allows an operator to identify whether a predetermined peripheral device is being accessed, and to check not only the presence or absence of access, but also the state of access. The purpose is to provide a computer system that allows you to check the information in more detail.

[0007]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention connects a host computer and a peripheral device that operates according to instructions from the host computer via a bus. The computer system is characterized by comprising a command importing means for importing a command for a predetermined peripheral device, and a display means for displaying a display corresponding to the command retrieved by the command importing means.

[Operation] According to the above-described structure, when a command is sent from the host computer to a predetermined peripheral device, a display corresponding to the command is performed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In the computer system in this embodiment, the host computer and peripheral devices are SCSI.
Connected via bus. Further, in this computer system, a display device (hereinafter referred to as a display device) that displays the access status is connected in a daisy chain to the SCSI bus. FIG. 1 is a block diagram showing the configuration of a display device connected to this computer system. Each device connected via SCSI bus c is assigned a unique identification number, or ID, and when an initiator specifies a target, this ID is assigned to each device.
D (hereinafter referred to as target ID) is used. 1 is a target ID setting switch, and a target ID assigned to a predetermined peripheral device is set in advance by the user. 2 is a comparison circuit which compares the target ID set in the target ID setting switch 1 and the target ID inputted from the bus c via the data signal line a, and outputs a match signal when the two match. Output. A command buffer address counter 3 supplies the command buffer 4 with an address at which the command data outputted to the bus c should be written. The command buffer 4 is located inside the single-chip microcomputer 20, and command data is taken in and written via the data signal line a2. In addition to the above-mentioned command buffer 4, the single-chip microcomputer 20 includes storage devices such as a ROM 7 and RAM 8, an I/O register 6, a mode setting switch 5, a timer 9, and a CPU 10 that controls each of these parts via a CPU bus d.
connected and configured. This single-chip microcomputer 20 controls the display of the display lamp 11.

[0009] Bus c also has eight data buses and one
Book parity bus, SEL (Select) bus, C/D (Control/Data) bus, REQ
It is composed of nine control buses such as a (Request) bus. Here, the data bus is connected to the comparator circuit 2 via the data signal line a1, and also connected to the data signal line a1.
2 to the command buffer 4. Also, among the control buses, the SEL bus is connected to the control signal line b1.
is connected to the comparison circuit 2 via the C/D bus and the RE
The Q bus is connected to the address counter 3 via control signal lines b2 and b2, respectively.

Next, the operation of this computer system will be explained along the flowchart shown in FIG. First, when power is input to the display device, step S1 is executed, and the target ID preset to the target ID setting switch is input to the comparison circuit 2.

[0011] Then, when the selection phase is started in this computer system, a SEL signal is output to bus c. Further, the target ID is sent to bus c by the initiator. As a result, step S2 is executed in the comparison circuit 2. That is,
Target ID sent to bus c by comparison circuit 2
and the target ID already entered in step S1 are compared (step 2). When the two match, the comparison circuit 2 outputs a match signal to the address counter 3, and the address counter 3 is enabled. If the two do not match, the process returns to step S2 without outputting anything.

[0012] When the operating state of this computer system shifts to the command phase, a C/D signal and a REQ signal are transmitted from the target to the initiator. Also, command data is transmitted from the initiator to the target. As a result, step S3
is executed, and the C/D signal and REQ signal are input to the address counter 3. Then, the address counter 3 outputs to the command buffer 4 the address at which the command data should be written. As a result, the command data is written to the specified address of the command buffer 4. If the target is a magnetic disk device, this command data includes target block address information, which represents head position information at the time of access.

[0013] Step S4 is then executed in the single-chip microcomputer 20. That is, CPU1
0 reads the target block address information from the command buffer 4 and causes the display lamp 11 to display a lighting pattern corresponding to the target block address information. For example, if the display lamp 11 in this embodiment is composed of four lamps as shown in FIG. 3, if the command data is an inner circumference seek command, all four lamps l1 to l4 are turned on. Further, when the command data is an outer circumference seek command, only the lamp l1 is turned on. In this way, the lighting pattern is changed. And step S
4, the process returns to step S2.

As described above, when the computer system shown in this embodiment is used, for example, in a predetermined magnetic disk device, the head seek operation such as the retract operation when the power is turned off is controlled by the lighting state of the access lamp. By checking this, abnormal operation can be detected. Further, when the access state is quantitative, the quantity can be visually grasped by expanding and contracting the display pattern into a bar shape corresponding to the quantity.

[0015]

As described above, according to the present invention, in a computer system in which a host computer and peripheral devices that operate according to instructions from the host computer are connected via a bus, a predetermined Since a command fetching means for fetching a command for a peripheral device and a display means for displaying a display corresponding to the command fetched by the command fetching means are provided, an operator can identify that a predetermined peripheral device is being accessed. It is possible to check not only the presence or absence of access, but also the status of access in more detail.

[0016]

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a flowchart of operations in an embodiment of the present invention.

FIG. 3 is a diagram showing a specific example of an indicator lamp in an embodiment of the present invention.

FIG. 4 is a conceptual diagram of connections using a SCSI bus.

FIG. 5 is a diagram showing a configuration when an access lamp is connected to a disk drive.

FIG. 6 is a diagram showing a configuration when an access lamp is lit using a BSY signal on a bus.

[Explanation of symbols]

1 Target ID setting switch 2 Comparison circuit 3 Command buffer/address register 20 Single-chip microcomputer

Claims (1)

[Claims] 1. A computer system in which a host computer and a peripheral device that operates according to instructions from the host computer are connected via a bus, comprising: a command importing means for importing a command to a predetermined peripheral device; 1. A computer system comprising: display means for displaying a command taken in by the command import means.