JPS62283457A - Magnetic tape device - Google Patents

Abstract

PURPOSE:To discriminate missing of block immediately at data read by writing a block number sent from a host device to the head of each block of a magnetic tape so as to make the write order of each block clear. CONSTITUTION:When the host device #0 gives an instruction of read of the content of a register 11 via a control line 1 to a magnetic tape device 100, a control section 10 of the device 100 reads the content of the register 11 and sends the result to the device #0 via a data line 20. The device #0 receiving it stores a value being the direction of '1' to the block number to the register 11 of the device 100 via the signal line 1 and the data line 20. When the device #0 gives a data write instruction, the control section 10 decodes the content of the signal line 1 to prepare the data transfer to the magnetic tape 12. In receiving the write data from the device #0, the control section 10 writes the content of the register 11 onto the tape 12 and the data from the device #0 are written via the data line. Thus, the block number is written in the head of each block.

Description

DETAILED DESCRIPTION OF THE INVENTION 3. Detailed Description of the Invention Field of Industrial Application The present invention relates to a magnetic tape device, and particularly relates to write control on a magnetic tape.

2. Description of the Related Art Conventionally, this type of magnetic tape device only records (writes) data sent from a host device onto a magnetic tape medium according to the recording density in response to a write command sent from a host device.

Problems to be Solved by the Invention However, in the above-mentioned conventional magnetic tape device, the block number (order relationship of each block) of each block recorded (written) on the magnetic tape medium is unknown, and for some reason In cases such as when a data block is missing,
The disadvantage is that it takes a lot of time to investigate the cause.

The present invention has been made in order to eliminate the above-mentioned drawbacks inherent in the conventional technology, and therefore, an object of the present invention is to make it possible to immediately identify missing data blocks when reading data from a magnetic tape at a later date. The object of the present invention is to provide a new magnetic tape device that has the following features.

Means for Solving the Problems In order to achieve the above object, a magnetic tape device according to the present invention includes a storage means for storing a block number sent from a higher-level device, and a storage means for storing a block number sent from a higher-level device. and a control section for controlling the entire magnetic tape device including control for writing the contents of the storage means onto the magnetic tape (medium).

EMBODIMENT OF THE INVENTION Next, a preferred embodiment of the present invention will be specifically explained with reference to the drawings.

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

Referring to FIG. 1, reference number 1 indicates the host device 0 to /
2 is a control signal line from/to the host device ◆1, and a control signal line for the 3-layer magnetic tape 15.

10 is a control unit of the magnetic tape device 100 including control (reading, writing) of the register 11, and an IIFi host device 0
%12 is a magnetic tape; 20 is a data line from/to the upper device 0; 21 is a data line from/to the upper device 1; 22
23 is a data line for writing data to the magnetic tape 12, 23 is a data line for writing data to the register 11 or reading data from the register 11, and 100 is a magnetic tape device.

When recording data on the magnetic tape 12 or reading information, set the normal magnetic tape 12 in the magnetic tape device L, and mark the beginning of the logical medium (hereinafter [BOTJ
(referred to as "Beginning Of Tape"). The control unit 10 controls the magnetic tape 1
When BOT 2 is detected, 10'' is written in the register 11 via the data line 23 (initial reset).

Next, a case will be described in which a data write command is sent from a host device +0 (such as a magnetic tape control device) to the control unit 10 of the magnetic tape device 100 via the control signal line 1.

The host device +0 performs the following before issuing a data write command to the magnetic tape device @100. The magnetic tape device 100 is instructed to read the contents of the register 11 via the control signal line 1. magnetic tape mold 100gl
The 94 unit 10 receives this, reads out the contents of the register 11 via the data line 23, and sends the data to the host device.
)20. The host device adds "1" to the read block number (contents of the register 11) and sends the value (which becomes the block number from which processing will start) to the register 11 of the magnetic tape device 100 on the control signal line 1 and the data line 20. Store everything through. After this, the host device will be installed. V
i Issue a write command for the data. Magnetic tape device 1
000 control unit 10 decodes control signal line 1. When the decoding result is a write instruction, the control unit 10 reads the register 11.
The contents are read out via the data line 23 and preparations are made for data transfer to the magnetic tape 12 via the data line 22. When write data from the host device O is sent via the data line 20t, the control unit 10 reads the read register 1.
The contents of 1 are written on the magnetic tape 12 (medium), and data that continues to be sent from the host device continues to be transferred (written) via the data line 22. In this way, the city block number is written at the beginning of each block.

On the other hand, the control IB line 2 and the data line 21 are used bare with the control signal line 1 and the data line 20, and are connected to the host device S1 and the host device S0, respectively. The magnetic tape device 100 of this embodiment can operate by receiving write commands alternately from the host device ÷ 0 and the host device + 1. Of course, control including a write command from either the host device O or the host device Φ1 is also possible.

Next, a case where a write command is issued from a host device≠1 will be described.

Similar to the host device ◆O, the contents of the register 11 are first updated via the control 1tl signal line 2 and the data line 21.

The host device 1 then issues a write command to the magnetic tape device 100 via the control signal line 2.

The control unit 10 of the magnetic tape device 100 connects the control ri line 2
, and when the m reading result is a write command.

The control unit 10 reads the contents of the register 11 via the data line 23 and prepares for data transfer to the magnetic tape 12 via the data line 22t. When write data from the host device 1 is sent via the data line 21, the control unit 10
The contents of the read register 11 are transferred to the magnetic tape 12 (
Then, data sent from the host device continues to be transferred (written) via the data line 22.

As described in detail, according to the present invention, the block number sent from the host device is written at the beginning of each block of the magnetic tape 12, thereby clarifying the writing headnote of each block, and later writing this magnetic tape. When reading the data on the tape 12, the effect of being able to immediately find out if a block is missing can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one practical example of the present invention. 1.2.3...Control word line, 10...Control unit, 1
1...Register, 12...Magnetic tape, 20, 21
, 22.23...Data line, 100...Magnetic tape device patent applicant NEC Corporation Representative Patent attorney Yutabe Kumagai Figure 1

Claims (1)

[Claims] In a magnetic tape device, a storage means for storing a block number sent from a host device, a means for reading the block number from the storage means according to an instruction from the host device, and a control for writing the contents of the storage means onto a magnetic tape (medium). A control unit that controls the entire magnetic tape device including the magnetic tape device.