JPS60150268A - Magnetic memory - Google Patents

Abstract

PURPOSE:To decide automatically and quickly the applicability of a cassette type magnetic tape in an off-line state by reproducing the test data on a test data recording area provided between the head of a magnetic tape and a normal data recording area. CONSTITUTION:A cassette type magnetic tape 1 is set at a point (a) of an area (1), and the prescribed data is written by a magnetic head 2. Then this data is read out by a reading head set into a magnetic head 2, and a measuring circuit 4 measures the output level voltage delivered from a reading circuit 3 and delivers it to an arithmetic circuit 6. A tape distance counting circuit 5 measures the distance from the program searching position of the tape 1 and delivers this count value to the circuit 6. The circuit 6 calculates the input signals given from the circuits 4 and 5 and delivers the result of this operation to a deciding circuit 9. The circuit 9 decides the applicability of the tape 1 based on a prescribed standard for decision and delivers the result of this decision to a control circuit 7.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention provides a removable cassette-type magnetic tape for recording predetermined digitized data. The present invention relates to a magnetic storage device that determines whether or not a magnetic tape can be used.

(b) Technology background Currently, there are many types for audio, video, computer use, etc.

A variety of removable cassette-type magnetic tapes are supplied, but it is difficult to accurately determine whether the supplied cassette-type magnetic tape is the most suitable recording medium for the device being used. The current situation is difficult to say. Whether cassette-type magnetic tape (recording digital data) for electronic computers that records especially important data is the most suitable recording medium in advance, or even if it is determined that it is the most suitable recording medium, it is most suitable for recording/reproducing the current data. It is especially important to determine in advance whether the computer is in a certain state, etc., as the use of electronic computers has become more sophisticated and complex. There is a need for the development of technology to accurately determine whether the recording medium that is currently being used is optimal for the device in use.

(C) Problems with the Prior Art In a storage device that uses a cassette-type magnetic tape as a recording medium, that is, in a conventional magnetic tape device, it is necessary to determine whether or not the cassette-type magnetic tape in use can be used for recording data from the cassette-type magnetic tape. A job (a unit of work carried out by a computer) is executed by reading or writing the data stored in the computer, and whether or not the computer can be used is determined by checking the state of error occurrence.

However, there are various ways in which errors can occur, and a 2-way determination cannot be made unambiguously, so it takes time to determine whether or not a device can be used, which increases the time occupied by the computer's central processing unit.

In addition, the operator must decide whether or not the final usability can be used, and there are many cassette tapes on the market, and even those that are not suitable for digitized data recording cannot be installed in the equipment. The problem is that it is not possible to quickly determine whether or not these cassette-type magnetic tapes can be used, and in an off-line state.

(d) Purpose of the Invention The purpose of the present invention is to provide a new magnetic storage device that solves the problem described in -1- above, and in particular, it is an object of the present invention to provide a new magnetic storage device that solves the problems described in -1-. The object of the present invention is to realize a magnetic storage device that can automatically and quickly make a decision in an off-line state.

(e) Structure of the Invention The present invention is a magnetic storage device that uses a removable cassette-type magnetic tape as a storage medium and records digitized data on the cassette-type magnetic tape. A determining means is provided for reproducing the test data in a test data recording area provided between the normal data recording area and determining whether or not the cassette type magnetic tape can be used, and determining whether the cassette type magnetic tape can be used. This can be achieved by using a magnetic storage device that is characterized by being able to automatically and quickly make decisions in an off-line state.

(f) Examples of the invention The present invention will be explained below with reference to Figure ml.

FIG. 1 shows one embodiment of the magnetic tape device according to the present invention, and a second embodiment of the magnetic tape device according to the present invention.
The figure shows an example of the use of the cassette type magnetic tape according to the present invention.
The figure is a characteristic diagram for determining whether or not it can be used in Figure 1.
A) is a characteristic diagram of the relationship between read voltage and write frequency, (
B) shows a characteristic diagram of the relationship between the error rate and the distance from the beginning of the cassette magnetic tape.

In the figure, 1 is a cassette magnetic tape, 2 is a magnetic head, 3 is a reading circuit, 4 is a measurement circuit, 5 is a tape distance counter circuit, 6 is an arithmetic circuit, 7 is a control circuit, 8 is a write circuit, and 9 is a judgment circuit. The circuits are shown respectively.

■～■ are cassette type magnetic tapes 1. The respective areas of J2, ■~■ are the characteristic curves, ■ are the areas for determining usability, ■ are the gaps, ■ are the regular data recording areas,
(2) shows a continuous voltage curve with respect to the write frequency, (2) shows a slice value curve with respect to the write frequency, and (2) shows an error lay 1 curve with respect to the cueing distance of the cassette type magnetic tape 1, respectively.

Also, a is the starting point of the area (■) that determines whether or not it can be used, b is the ending point of the area (■) that determines whether or not it can be used, C is the starting point of the normal data recording area (■), and d is when the read voltage frequency is 2F. The slice value, e is the slice value at the frequency IF of the read voltage, f is the usability determination point 2g based on the error rate, the usability boundary line of the error rate, and h is the straight line connecting point a and point The intersection of the error rate with the usability boundary line g becomes the usability determination point f based on the error rate)
.

IF and 2F indicate write frequencies, respectively.

This embodiment includes a cassette-type magnetic tape 1 for recording data digitally and serially, and a magnetic head 2 for magnetically recording/reproducing the cassette-type magnetic tape 1. A readout circuit 3 that converts the data read by the magnetic head 2 into an electrical signal.
．． A measurement circuit 4 that measures the output level voltage of the readout circuit 3
．． Tape distance counter circuit for counting the distance traveled from the beginning of the cassette type magnetic tape 1 5. An arithmetic circuit 6 which inputs the output from the measuring circuit 4 and the output from the tape distance counter circuit 5 and calculates the distance from the beginning of the cassette magnetic tape 1 versus the successive output voltage. Read operation.

The control circuit 7 includes a control circuit 7 for controlling overall operations such as writing operations, and a determination circuit 9 for determining whether or not the cassette-type magnetic tape 1 can be used based on the outputs of the calculation circuits 17 & 6.

In addition, the normal cassette type magnetic tape 1 is 1 to several meters from the beginning.
is an unused area. Approximately 5111 of this area is used as the area (2) for determining whether or not the cassette type magnetic tape 1 can be used in this embodiment, and predetermined data is recorded in this area (2) in an off-line state to determine in advance whether or not the cassette type magnetic tape 1 can be used.

Next, the method and operation of determining whether or not the cassette type magnetic tape 1 can be used will be explained.

The magnetic tape device is taken off-line from the system, and the tape 1 in the upper cassette is placed at point a in area (2), and under control from the control circuit 7, the write circuit 8 applies a write current to the magnetic head 2. Insert 1 of the specified data. At the same time, predetermined data is read out by a read head ' built into the magnetic node 2 and outputted to the read circuit 3. Measurement time 1? R4 measures the output voltage from the readout circuit 3 and outputs the result to the arithmetic circuit 6.

On the other hand, the tape distance counter circuit 5 counts the distance from the beginning of the cassette type borosilicate tape 1 and outputs the result to the arithmetic circuit 6 as well. The marking circuit 6 includes a measuring circuit 4 and a tape release counter circuit 5. ! : calculates the input signal from and outputs the result to the determination circuit 9. The judgment circuit 9 uses a predetermined judgment criterion.

It is determined whether or not the cassette type magnetic tape 1 can be used, and the result is output to the control circuit 7.

If it is not usable, the control circuit 7 displays a lamp to that effect and automatically ejects the cassette type magnetic tape 1.

Next, it is assumed that the determination criteria of the determination circuit 9 are as follows.

(1): When writing is performed at the frequency IF and the data is read out, the continuous output voltage has a slice value of 0 or more as shown in FIG. 3(A).

(2): When data is written at a frequency of 2F and read out, the continuous output voltage has a slice value of 4 or more as shown in FIG. 3(A).

(31n) The ability (ratio of level (2)/level (I)) is above a certain level (usually 70% or above).

(4): Errors during reading after DC erasure and after writing at a frequency of 2F decrease at a constant rate in inverse proportion to the distance from the beginning of the cassette magnetic tape 1 (characteristics are shown in Figure 3 (B)). ) From point C onwards, the error must be less than or equal to Cf point) in the normal data recording area (nlJ). Also, the error rate judgment point f is before point C.

If all the above conditions (11 to (4)) are satisfied, use 0J.
If there is even one item that is not satisfied, the determination circuit 9 determines that it is unusable. Furthermore, the write data pattern and determination method described above are just one embodiment of the present invention, and it is clear that the object of the present invention can be achieved even with other data patterns or determination methods.

(g) Effects of the Invention According to the present invention as described above, there is provided a magnetic storage device that can automatically and quickly determine whether or not it is applicable to a recording medium device that will be used in the future or is already in use, and in an offline state. It has the effect of being able to provide the following.

[Brief explanation of the drawing]

FIG. 1 shows one embodiment of the magnetic tape device according to the present invention, and a second embodiment of the magnetic tape device according to the present invention.
The figure shows an example of the use of the cassette type magnetic tape according to the present invention.
The figures each show characteristic diagrams for determining whether or not the product can be used. In the figure, 1 is a cassette magnetic tape, 2 is a magnetic head, 3 is a continuous output circuit, 4 is a measurement circuit, 5 is a tape distance counter circuit, 6 is an arithmetic circuit, 7 is a control circuit, 8 is a write circuit, and 9 is a write circuit. The determination circuits are shown respectively. 0

Claims (1)

[Scope of Claim] A magnetic storage device that uses a removable cassette-type magnetic tape as a storage medium and records digitized data on the cassette-type magnetic tape. The present invention is characterized in that a determining means is provided for reproducing the test data in a test data recording area provided between the beginning of the magnetic tape and the regular data recording area and determining whether or not the cassette type magnetic tape can be used. Magnetic storage device.