JPH0816325A - Method and device for interfacing - Google Patents

Abstract

PURPOSE:To shorten the processing time of any prescribed function and to accelerate the operation of an entire system. CONSTITUTION:A data line from a host computer 200 is bidirectionally connected to a bank memory 4a. On the other hand, a data line from a bank memory 4b is bidirectionally connected to a data recorder 300. Further, memory control circuits 5 and 6 and a bank switching circuit 7 are respectively provided corresponding to the bank memories 4a and 4b. Then, a designating means (dip switch) 9 is provided to designate any recording rate, a signal from this designating means 9 is supplied through a main CPU 1 to a clock signal generator 10, and a clock signal at the frequency corresponding to the rate designated by the designating means 9 and the main CPU 1 is generated. This clock signal is supplied to a memory control circuit 6 and the data recorder 300. Thus, control is normally performed at the recording rate set by the designating means 9 but in the prescribed function, the control is performed at the recording rate of peak speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interface method and apparatus used between a data recorder for recording data supplied at a variable transfer rate and a host computer.

[0002]

2. Description of the Related Art For example, a data recorder using a helical scan type recording / reproducing apparatus has been proposed. That is, for example, ANSI X3.175-1990 ID-
In a digital data recorder conforming to 1 format, 4 tracks recorded by the helical scan head are set as 1 ID, and 144 tracks are set in 1 ID (4 tracks).
Data of 432 bytes is recorded.
Then, for example, 100,000 IDs or more are recorded on one recording medium (cassette tape).

In such a data recorder, the recording rate of the data recorder is changed according to the data transfer rate from the host computer. That is, in the helical scan type recording / reproducing apparatus, the recording rate can be changed while maintaining the track format by changing the rotational speed of the head and the transfer speed of the recording medium at an equal rate. Can be adjusted to the data transfer rate from the host computer.

Therefore, an interface for smoothly operating the data recorder and the host computer is provided. That is, in this interface, for example, data from the host computer is accumulated in the memory, and when the accumulated amount of this data reaches a predetermined amount, recording to the data recorder is started. The reproduced data from the data recorder is also stored in the memory, and the stored data is output in response to a request from the host computer.

In this way, in this interface, control is performed so as to reduce the number of times of recording and reproduction by the data recorder. That is, this control prevents frequent driving / stopping of the data recorder and reduces the risk of damage to the mechanical portion of the data recorder and the recording medium.

This interface is provided with a designation means for designating the recording rate of the data recorder,
By designating the data transfer rate from the above-mentioned host computer to this designating means, the data recorder is driven at this rate, and the data accumulated in the memory is read and recorded. The data transfer rate from the host computer is, for example, 4M (byte / sec.), 8M (byte / sec.), 16M.
(Byte / sec.) Etc. are specified.

In the data recorder as described above, in the specified format (DTF), for example, the following specified data is recorded at the head of the recording medium.

That is, for example, as shown in FIG. 6, dummy data is recorded from the leading end of the tape to 8000 ID, which is a dummy area and which is a run-up section for writing and reading of the subsequent effective area. Further, from 8001 ID to 8700 ID, VSIT data for managing the entire tape is recorded. This VSIT data is 1 for each
It is formed with 00ID and is recorded seven times in order to protect it from being lost. From 8701 ID to 106
Dummy data is recorded up to 00ID.

Also, 10601 ID to 11300 ID
Up to the above, DIT data for managing the user data area is recorded. One of this DIT data is 100 ID
Is formed, and is recorded repeatedly 7 times in order to protect a missing portion or the like. Furthermore, from 11301 ID to 13200I
Up to D, dummy data is recorded. Then, after that, data including the data sent from the host computer and the tape mark indicating the delimiter of the data is recorded.

Therefore, in the above data recorder, for example, when data is recorded on an unused recording medium, first of all, an initialization process for recording the data defined at the beginning as described above is performed. There is a need. That is, such data defined at the beginning is created by, for example, the above-mentioned interface and stored in the memory. Then, the data recorder is driven by this interface, and the data stored in the memory is read and recorded.

However, in the above data recorder,
The recording rate depends on the data transfer rate from the host computer specified in the interface specification means.
The data recorder is driven at this rate, and the data stored in the memory is read and recording is performed. That is, for example, when the data transfer rate from the host computer is 4 M (bytes / sec.), The recording rate in the data recorder is all 4 M (bytes / sec.).

On the other hand, for example, when the above-mentioned initialization is performed, it is necessary to record the 13200 ID only with the data. If the recording rate of the designated data recorder is 4M (bytes / sec.), Then only 144432 (bytes / ID) x 13200 (ID) ÷ 4M ( Bytes / sec.) ≈455 (sec.) Is required, which takes about 7.5 minutes. Note that this time is the time required to record data, and does not include tape transfer or the like.

By the way, when performing such initialization,
All the data to be recorded is created by the interface, and data is not exchanged with the host computer, for example, only by receiving an initialization start command. In addition, for such processing that does not involve data exchange with the host computer, reading and writing of DIT when loading and unloading a recording medium, and restoration of data when this DIT is not correctly recorded. Etc.

[0014]

This application has been made in view of such a point, and the problem to be solved is that the conventional device takes a very long time at the time of initialization, for example. It is necessary, which slows down the operation of the entire system.

[0015]

According to a first aspect of the present invention, a data recorder for recording data supplied at a variable transfer rate and a host computer accumulate data from the host computer. The accumulated data is read at a designated transfer rate and supplied to the data recorder, and when the data recorder is driven by a predetermined function, the transfer rate is set to the maximum speed regardless of the designation. This is the interface method.

A second means according to the present invention is a data recorder 30 for recording data supplied at a variable transfer rate.
0 and the host computer 200, the interface device 100 is provided with a memory (bank memory 4) for storing data from the host computer.
a, 4b), the transfer rate designating means 9 and a generating means 10 for generating a clock signal in accordance with the designation of the designating means, and stored in the memory in accordance with the clock signal from the generating means. The data is read (memory control circuit 6) and supplied to the data recorder together with the clock signal, and when the data recorder is driven by a predetermined function (sub CPU 3), the clock signal generated by the generating means is supplied. The interface device is set to have the maximum speed (main CPU 1) regardless of the designation of the designation means.

According to a third means of the present invention, in the interface method or apparatus according to the first or second means, the predetermined function of the data recorder includes at least a function of initializing a recording medium of the data recorder. An interface method or device characterized by the above.

According to a fourth aspect of the present invention, in the interface method or apparatus according to the first or second aspect, the predetermined function of the data recorder is at least a function of loading and unloading a recording medium of the data recorder. An interface method or device including:

According to a fifth aspect of the present invention, in the interface method or apparatus according to the first or second aspect, the predetermined function of the data recorder is at least to restore the data recorded on the recording medium of the data recorder. It is an interface method or apparatus characterized by including the function of.

[0020]

According to this, when the data from the host computer is accumulated, the accumulated data is read at a designated transfer rate and supplied to the data recorder, and when the data recorder is driven by a predetermined function, By setting the transfer rate to the maximum speed regardless of the specification, processing without data exchange with the host computer can be performed at the maximum speed in a short time. Can be faster.

Further, a memory for accumulating data from the host computer, a transfer rate designating means, a generating means for generating a clock signal according to the designation of the designating means, and a memory according to the clock signal from the generating means. The accumulated data is read out and supplied to the data recorder together with the clock signal, and when the data recorder is driven by a predetermined function, the clock signal generated by the generation means is set to the maximum speed regardless of the designation of the designation means. As a result, the processing without data exchange with the host computer can be performed at the maximum speed in a short time, and the time of such processing can be shortened to speed up the operation of the entire system.

Further, the predetermined function of the data recorder is
By including at least the function of initializing the recording medium of the data recorder, it is possible to shorten the initialization processing time and speed up the operation of the entire system.

Further, the predetermined function of the data recorder includes at least the function of loading and unloading the recording medium of the data recorder, thereby shortening the load and unload processing time and accelerating the operation of the entire system. be able to.

Further, the predetermined function of the data recorder is
By including at least the function of recovering the data recorded on the recording medium of the data recorder, it is possible to shorten the processing time of the data recovery and accelerate the operation of the entire system.

[0025]

1 is an interface device 100 for implementing an interface method and apparatus according to the present invention.
The structure of an example is shown.

In FIG. 1, the host computer 2
Data lines from 00 and control (command) lines are bidirectionally connected to the interface device 100. A data line and a control (control signal) line from the interface device 100 are bidirectionally connected to the data recorder 300. Further, the clock signal line from the interface device 100 is
It is connected to the data recorder 300.

In the interface device 100, 1 is a main CPU, and a control line from a host computer 200 is bidirectionally connected to the main CPU 1. Then, a command is mainly supplied from the host computer 200 to the main CPU 1.
Further, an acknowledge or the like from the main CPU 1 is supplied to the host computer 200. And this main CP
From U1, the entire interface device 100 is controlled by using a sub CPU 3 and the like described later.

Reference numeral 2 is a dual port RAM, and this dual port RAM 2 is used for command communication between the main CPU 1 and the sub CPU 3. Further, the control line from the sub CPU 3 is bidirectionally connected to the data recorder 300. And this sub C
The PU 3 receives a command from the main CPU 1 to form a system control signal and supplies this signal to the data recorder 300 and the like. Further, the address etc. from the data recorder 300 is supplied to the sub CPU 3.

Further, the first and second bank memories 4
a and 4b are provided. And the host computer 20
Data lines from 0 are bidirectionally connected to the bank memory 4a. Further, the data lines from the bank memory 4b are bidirectionally connected to the data recorder 300. Further, memory control circuits 5 and 6 are provided for the bank memories 4a and 4b, respectively. The main CPU 1 is bidirectionally connected to the memory control circuit 5. The sub CPU 3 is bidirectionally connected to the memory control circuit 6.

Further, a bank switching circuit 7 is provided for the bank memories 4a and 4b. A signal from the sub CPU 3 is supplied to the bank switching circuit 7, and the bank memories 4a and 4b are switched to each other at a necessary timing. Further, a sub memory 8 is provided for the main CPU 1. Further, a designation unit 9 (DIP switch) for designating the recording rate of the data recorder 300 is provided, and a signal from the designation unit 9 is supplied to the main CPU 1.

Further, a clock signal generator 10 is provided, and a clock signal having a frequency corresponding to the rate designated by the designating means 9 is generated by a signal from the main CPU 1. This clock signal is supplied to the memory control circuit 6 to control the transfer rate when the bank memory 4b exchanges data with the data recorder 300. Further, this clock signal is supplied to the data recorder 300,
The drive speed (recording rate) is controlled.

Therefore, in this apparatus, for example, when the recording medium is initialized, first, the host computer 20
When the main CPU 1 receives an initialization command from 0, the main CPU 1 requests the clock generator 10 to generate a clock signal corresponding to a maximum speed, for example, 16 M (bytes / sec.).

A tape rewinding request is issued from the main CPU 1 to the sub CPU 3. This makes sub C
A rewinding control signal is output from the PU 3 to the data recorder 300. Then, for example, when the tape is rewound to the beginning as shown in FIG. 2A, the detection signal is returned from the data recorder 300 to the sub CPU 3.

Next, the main CPU 1 to the sub CPU 3
At the same time, a request is made to record only a predetermined ID number from the beginning (0 ID) to the 6976 ID of the tape. As a result, a control signal for recording only the ID number is supplied from the sub CPU 3 to the data recorder 300. Then, for example, as shown in B of FIG. 2, 69 from the beginning (0ID) of the tape
Only ID numbers are recorded up to 76 IDs.

Next, a dummy data is formed in the bank memory 4b by a signal from the main CPU 1. Further, a request to record the dummy data from 6977 ID to 8000 ID is issued from the main CPU 1 to the sub CPU 3. As a result, the control signal from the sub CPU 3 is supplied to the data recorder 300. Then, as shown in C of FIG. 2, dummy data is recorded from 6977 ID to 8000 ID.

Next, a signal from the main CPU 1 forms VIST data in the bank memory 4b. Further, this VIST data is converted from 8001 ID to 8700 ID.
The request to record is from the main CPU1 to the sub CPU
Issued in 3. As a result, the control signal from the sub CPU 3 is supplied to the data recorder 300. Then, as shown in D of FIG. 2, VIST data is recorded from 8001 ID to 8700 ID.

Next, a dummy data is formed in the bank memory 4b by a signal from the main CPU 1. Further, the main CPU 1 issues a request to record the dummy data from 8701 ID to 10600 ID to the sub CPU 3. As a result, the control signal from the sub CPU 3 is supplied to the data recorder 300. Then, as shown in E of FIG. 2, dummy data is recorded from 8701 ID to 10600 ID.

Next, DIT data is formed in the bank memory 4b by a signal from the main CPU 1. Furthermore, this DIT data is converted from 10601 ID to 11300 ID.
The request to record is from the main CPU1 to the sub CPU
Issued in 3. As a result, the control signal from the sub CPU 3 is supplied to the data recorder 300. Then, as shown in F of FIG. 2, DIT data is recorded from 10601 ID to 11300 ID.

Next, dummy data is formed in the bank memory 4b by a signal from the main CPU 1. Further, a request to record this dummy data from 11301 ID to 13200 ID is issued from the main CPU 1 to the sub CPU 3
Issued to. As a result, the control signal from the sub CPU 3 is supplied to the data recorder 300. And G in FIG.
As shown in, dummy data is recorded from 11301 ID to 13200 ID.

Next, the main CPU 1 issues a tape rewinding request to the sub CPU 3. This makes sub C
A rewinding control signal is output from the PU 3 to the data recorder 300. Then, for example, when the tape is rewound to the beginning as shown in H of FIG. 2, the detection signal is returned from the data recorder 300 to the sub CPU 3.

Further, the signal from the designating means 9 is the main C
The CPU 1 makes a determination, and the main CPU 1 issues a request to the clock generator 10 to generate a clock signal corresponding to the rate designated by the designating means 9. Further, a signal indicating that these processes are completed is sent to the main CPU.
1 to the host computer 200.

In this apparatus, when the initialization is performed, it is necessary to record the 13200 ID only with the data. Therefore, for example, when a rate of 4 M (bytes / sec.) Is designated in the designation means 9, conventionally, 144432 (bytes / ID) × 13200 (ID) / 4 M (bytes / sec.) ≈455 (sec. ) Time was needed.

On the other hand, in the above-mentioned apparatus, the initialization process is performed at the maximum speed of 16 M (bytes / sec.) Regardless of the designation by the designating means 9, and the required time is 144432. (Byte / ID) × 13200 (ID) ÷ 16M
(Bytes / sec.) ≈114 (sec.) And the processing time can be shortened.

Thus, according to the above-described method and apparatus, the data from the host computer is accumulated, the accumulated data is read out at the designated transfer rate and supplied to the data recorder, and the data recorder has a predetermined function. By setting the transfer rate to the maximum speed regardless of the specification when driving, processing without data exchange with the host computer can be performed at the maximum speed in a short time, thus reducing the processing time. Thus, the operation of the entire system can be speeded up.

A memory (bank memory 4a, 4b) for accumulating data from the host computer 200,
Transfer rate designating means 9, generating means 10 for generating a clock signal in accordance with the designation of the designating means, data stored in the memory in accordance with the clock signal from the generating means (memory control circuit 6), When supplying the data recorder with the clock signal and driving the data recorder with a predetermined function (sub CPU 3), the clock signal generated by the generating means is set to the maximum speed regardless of the designation of the designating means (main CPU 1). As a result, the processing without data exchange with the host computer can be performed at the maximum speed in a short time, and the time of such processing can be shortened to accelerate the operation of the entire system.

Further, the predetermined function of the data recorder is
By including at least the function of initializing the recording medium of the data recorder, it is possible to shorten the initialization processing time and speed up the operation of the entire system.

Further, in the above-mentioned apparatus, in addition to the initialization, the processing which does not exchange data with the host computer has functions such as loading and unloading of the recording medium.

That is, first, in the loading process, with the recording medium loaded in the helical scan head (A in FIG. 3), the main CPU 1 causes the clock generator 1 to operate.
A request is made to generate a clock signal corresponding to a maximum speed of 0, for example 16 M (bytes / sec.).

A reproduction request is issued from the main CPU 1 to the sub CPU 3. As a result, a reproduction control signal is supplied from the sub CPU 3 to the data recorder 300.
Then, this reproduced signal is checked to confirm whether or not the recording medium is unused (uninitialized).

Next, the main CPU 1 to the sub CPU 3
Then, a request for reproducing 100 IDs from 8001 IDs is issued. As a result, the sub CPU 3 supplies the data recorder 300 with a control signal for reproducing 100 IDs from 8001 IDs. Then, as shown in FIG. 3B, VS
Data for 100 IDs in the IT area is reproduced, and it is determined whether or not the data is recorded in the above format (DTF).

Next, the main CPU 1 to the sub CPU 3
Then, a request to reproduce 100 IDs from 10601 IDs is issued. As a result, the sub CPU 3 supplies the data recorder 300 with a control signal for reproducing 10ID to 100ID. Then, as shown in FIG. 3C, the data of 100 ID of the DIT area is reproduced, the data of the DIT which manages the area of the user data described above is reproduced and stored in the sub memory 8.

Next, the use start flag of the DIT data stored in the sub memory 8 is rewritten by the main CPU 1 so as to indicate that it is in use, and the rewritten DIT data is formed in the bank memory 4b. . Further, a request to record this DIT data from 10601 ID to 11300 ID is issued from the main CPU 1 to the sub CPU 3
Issued to. As a result, the control signal from the sub CPU 3 is supplied to the data recorder 300. And D in FIG.
As shown in, DIT data is recorded from 10601 ID to 11300 ID.

Next, the main CPU 1 to the sub CPU 3
Then, a request to move the head to 13200 ID is issued. As a result, the data recorder 30 is transferred from the sub CPU 3
The transfer control signal is output to 0. Then, for example, when the head is moved to 13200ID as shown in E of FIG. 3, the detection signal is sent from the data recorder 300 to the sub-CP.
Returned to U3.

Further, the signal from the designating means 9 is the main C
The CPU 1 makes a determination, and the main CPU 1 issues a request to the clock generator 10 to generate a clock signal corresponding to the rate designated by the designating means 9. Further, a signal indicating that these processes are completed is sent to the main CPU.
1 to the host computer 200.

In this apparatus, when the loading process is performed, it is necessary to perform the reproduction / recording of 900ID only with the data. Therefore, for example, 4M (bytes / s
If the rate of ec.) was specified, conventionally 144444 (byte / ID) x 900 (ID) ÷ 4M (byte
/ sec.) ≒ 32 (sec.) time was required.

On the other hand, in the above-mentioned apparatus, the initialization process is performed at the maximum speed of 16 M (bytes / sec.) Regardless of the designation by the designating means 9, and the required time is 144432. (Bytes / ID) × 900 (ID) ÷ 16M (Bytes / sec.) ≈8 (sec.), And the processing time can be shortened.

In the unload process, the unload command from the host computer 200 is sent to the main C.
When PU1 receives it, the main CPU 1 issues a request to the clock generator 10 to generate a clock signal corresponding to the maximum speed, for example, 16 M (bytes / sec.).

Next, the main CPU 1 to the sub CPU 3
Then, a request to reproduce 100 IDs from 10601 IDs is issued. As a result, the sub CPU 3 supplies the data recorder 300 with a control signal for reproducing 10ID to 100ID. Then, as shown in FIG. 4A, the data of 100 ID of the DIT area is reproduced, and the data of the DIT for managing the above-mentioned user data area is reproduced and stored in the sub memory 8.

Next, data for managing the updated user data area is added to the DIT data stored in the sub memory 8 in the main CPU 1, and the use start flag indicates that the use is completed. And the rewritten DIT data is formed in the bank memory 4b. Furthermore, this DIT data is 10601I
Request to record from D to 11300 ID is main C
It is issued from PU1 to sub CPU3. As a result, the control signal from the sub CPU 3 is supplied to the data recorder 300. Then, as shown in FIG. 4B, 10601ID
DIT data is recorded from ID 11 to ID 11300.

Next, the main CPU 1 issues a tape rewinding request to the sub CPU 3. This makes sub C
A rewinding control signal is output from the PU 3 to the data recorder 300. Then, for example, when the tape is rewound to the beginning as shown in C of FIG. 4, the detection signal is returned from the data recorder 300 to the sub CPU 3. Further, a control signal for ejecting the recording medium from the helical scan head is supplied from the sub CPU 3 to the data recorder 300.

In this device, when the loading process is performed, it is necessary to perform the reproduction / recording of 800ID only by the data. Therefore, for example, 4M (bytes / s
If the rate of ec.) was specified, conventionally it is 144432 (byte / ID) × 800 (ID) ÷ 4M (byte
/ sec.) ≈ 28 (sec.) time was required.

On the other hand, in the above-mentioned device, the initialization process is performed at the maximum speed of 16 M (bytes / sec.) Regardless of the designation of the designation means 9, and the required time is 144432. (Bytes / ID) × 800 (ID) ÷ 16M (Bytes / sec.) ≈7 (sec.), And the processing time can be shortened.

Thus, according to the above method and apparatus, the predetermined function of the data recorder includes at least the function of loading and unloading the recording medium of the data recorder, thereby shortening the load and unload processing time. Thus, the operation of the entire system can be speeded up.

Further, in the above-mentioned load processing, 1
When the use start flag of the DIT data reproduced from 0601 ID to 100 ID indicates that it is in use, it is determined that the unload process is not correctly performed at the end of the previous use. In this case, the data recorded on the recording medium is read out, and the DIT data restoration process for managing the user data area is performed. This process is also a process in which no data is exchanged with the host computer.

Therefore, in the case of performing this data restoration process, when the main CPU 1 first receives a data restoration command from the host computer 200, the main C
The maximum speed from PU1 to clock generator 10, eg 16
A request is made to generate a clock signal corresponding to M (bytes / sec.).

Further, the main CPU 1 requests the sub CPU 3 to move the head to 13200ID.
As a result, a transfer control signal is output from the sub CPU 3 to the data recorder 300. Then, for example, when the head is moved to 13200ID as shown in FIG. 5A, the detection signal is returned from the data recorder 300 to the sub CPU 3.

Next, the main CPU 1 to the sub CPU 3
Then, a request is issued to reproduce the data recorded from the 13201 ID to the end position (EOD) of the data recorded by the user. As a result, the control signal for reproducing the user data area is supplied from the sub CPU 3 to the data recorder 300. Then, for example, as shown in B and C of FIG. 5, the end position (EOD) of the data from 13201 ID
The data recorded up to is reproduced.

Next, the main CPU 1 performs a process of reconstructing DIT data for managing the user data area from the reproduced data. Further main CPU1
DI reconfigured in the bank memory 4b by the signal from
The data of T is formed. This DIT data is 1
A request to record from 0601 ID to 11300 ID is issued from the main CPU 1 to the sub CPU 3. As a result, the control signal from the sub CPU 3 is supplied to the data recorder 300. Then, as shown in D of FIG.
DIT data is recorded from 0601 ID to 11300 ID.

Next, the main CPU 1 issues a tape rewinding request to the sub CPU 3. This makes sub C
A rewinding control signal is output from the PU 3 to the data recorder 300. Then, for example, when the tape is rewound to the beginning as shown in E of FIG. 5, the detection signal is returned from the data recorder 300 to the sub CPU 3.

Further, the signal from the designating means 9 is the main C
The CPU 1 makes a determination, and the main CPU 1 issues a request to the clock generator 10 to generate a clock signal corresponding to the rate designated by the designating means 9. Further, a signal indicating that these processes are completed is sent to the main CPU.
1 to the host computer 200.

In this device, when data restoration processing is performed, it is necessary to perform reproduction / recording of 100,000 IDs or more with data alone. Therefore, for example, 4M in the designation means 9
If a rate of (bytes / sec.) Was specified, 144432 (bytes / ID) x 100000 (ID) / 4M was used in the past.
(Bytes / sec.) ≈ 3446 (sec.) Time was required.

On the other hand, in the above-mentioned device, the initialization process is performed at the maximum speed of 16 M (bytes / sec.) Regardless of the designation of the designating means 9, and the required time is 144432. (Byte / ID) x 100000 (ID) / 16M
(Bytes / sec.) ≈830 (sec.), And the processing time can be shortened.

Thus, according to the above method and apparatus, the predetermined function of the data recorder includes at least the function of restoring the data recorded on the recording medium of the data recorder, thereby reducing the time required for the data restoration process. Then, the operation of the entire system can be speeded up.

In the method and apparatus described above, in the system using the conventional standard expansion board (VME board), data is transferred to the interface section through the VME bus. In that case, the data handled by a normal VME is usually read from the beginning when writing and reading from the beginning of the tape. Even in such an apparatus, if the data has the concept of a file and one tape is managed in file units,
The invention of the present application described above can be applied.

Further, when the so-called file format such as the above defined format (DTF) is adopted in the interface for the general variable rate data recorder, the invention of the present application described above can be applied. .

In addition, the specified format (D
Even if it is not TF), a sequential access device having a file format must have the functions of initialization, loading, and unloading. If the data recorder has a variable rate, the invention of the present application described above is required. Can be applied.

Furthermore, when copying the recorded data, there is a function of using the file format to perform logical copying, such as file unit or block unit, rather than simple dubbing between tapes. Even when copying such recorded data, this function can be performed regardless of the transfer capability of the host computer, and the invention of the present application described above can be applied.

[0078]

According to the present invention, the data from the host computer is accumulated, the accumulated data is read out at the designated transfer rate and supplied to the data recorder, and the data recorder is driven by a predetermined function. In this case, by setting the transfer rate to the maximum speed regardless of the specification, it is possible to perform processing without data exchange with the host computer at the maximum speed in a short time. The whole operation can be speeded up.

Further, the memory for storing the data from the host computer, the transfer rate designating means, the generating means for generating the clock signal according to the designation of the designating means, and the memory according to the clock signal from the generating means are stored in the memory. The accumulated data is read out and supplied to the data recorder together with the clock signal, and when the data recorder is driven by a predetermined function, the clock signal generated by the generation means is set to the maximum speed regardless of the designation of the designation means. As a result, processing without data exchange with the host computer can be performed at the maximum speed in a short time, and the time for such processing can be shortened to speed up the operation of the entire system.

Furthermore, the predetermined function of the data recorder is
By including at least the function of initializing the recording medium of the data recorder, it has become possible to shorten the initialization processing time and speed up the operation of the entire system.

Further, the predetermined function of the data recorder includes at least the function of loading and unloading the recording medium of the data recorder, thereby shortening the load and unload processing time and accelerating the operation of the entire system. I was able to do it.

Further, the predetermined function of the data recorder is
By including at least the function of restoring the data recorded on the recording medium of the data recorder, it has become possible to shorten the processing time of the data restoration and speed up the operation of the entire system.

[Brief description of drawings]

FIG. 1 is a block diagram of an example of an interface device for implementing an interface method and device according to the present invention.

FIG. 2 is a diagram for explaining the initialization process.

FIG. 3 is a diagram for explaining the loading process.

FIG. 4 is a diagram for explaining the unloading process.

FIG. 5 is a diagram for explaining a process of restoring the data.

FIG. 6 is a diagram for explaining data defined at the beginning of a recording medium.

[Explanation of symbols]

 1 Main CPU 2 Dual Port RAM 3 Sub CPU 4a, 4b First and Second Bank Memory 5, 6 Memory Control Circuit 7 Bank Switching Circuit 8 Sub Memory 9 Designating Means 10 Clock Signal Generator 100 Interface Device 200 Host Computer 300 Data Recorder

Claims (5)

[Claims] 1. A data recorder, which records data supplied at a variable transfer rate, and a host computer store data from the host computer, and read the stored data at a specified transfer rate. And an interface method in which the transfer rate is set to the maximum speed regardless of the designation when the data recorder is driven by a predetermined function. 2. An interface device provided between a data recorder for recording data supplied at a variable transfer rate and a host computer, the memory accumulating data from the host computer, and the transfer rate designating means. And a generating means for generating a clock signal according to the designation of the designating means, the data stored in the memory is read according to the clock signal from the generating means, and is supplied to the data recorder together with the clock signal. In addition, when the data recorder is driven by a predetermined function, the clock signal generated by the generating means is set to the maximum speed regardless of the designation of the designating means. 3. The interface method or device according to claim 1, wherein the predetermined function of the data recorder includes at least a function of initializing a recording medium of the data recorder. . 4. The interface method or apparatus according to claim 1 or 2, wherein the predetermined function of the data recorder includes at least a function of loading and unloading a recording medium of the data recorder. Or device. 5. The interface method or apparatus according to claim 1 or 2, wherein the predetermined function of the data recorder includes at least a function of restoring data recorded on a recording medium of the data recorder. Interface method or device.