JPH01307983A - Digital data recording and playback device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a digital data recording and reproducing apparatus that can place a plurality of indexes at arbitrary positions on a tape.

BACKGROUND OF THE INVENTION Conventionally, few magnetic tape devices for data recording have a configuration in which famous songs, identification numbers, recording position information, etc. of files recorded on the tape are recorded together as an index. In recent years, there have been only some cases where index (also called -! or directory) information is configured in a different format.

Problems to be Solved by the Invention However, there are restrictions, such as the index portion being provided at only one location on the tape or having to be provided at a specific location (for example, at the beginning of the tape).

In other words, since the index portion is frequently accessed, the tape in the index portion deteriorates quickly, resulting in concerns about reliability. If part of this index becomes unreadable, in the worst case, the entire data on that tape becomes unusable.

Further, even when file data is recorded near the end of the tape, in order to update the index, the tape must be rewound to the beginning of the tape where the index should be recorded, which significantly reduces operability.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention provides a digital data recording and reproducing apparatus that ensures sufficient reliability even when the index portion is accessed frequently and that has good operability even when updating the index.

Means for Solving the Problems In order to solve the above problems, the digital data recording and reproducing apparatus of the present invention includes a current position management means for managing the position of the recording and reproducing means on the tape, and a current position management means for managing the position of the recording and reproducing means on the tape. Recording and playback control means for controlling file data recording and playback; index recording and playback control means for controlling the recording and playback of indexes, which are management information for each file recorded on the tape; The apparatus is equipped with an index recognition means for identifying the recorded portion, a current position management means, a file data recording and reproduction control means, an index recording and reproduction control means, and a file management control section for controlling the index recognition means.

Effect of the present invention With the above configuration, it is not necessary to specify the position of the index, so it is possible to construct a flexible system configuration, and by dividing or arranging frequently accessed index parts, one This reduces the number of accesses to the index section, prevents deterioration of only a specific portion of the tape, and ensures sufficient reliability.

In addition, by arranging file data and the index section related to the file data close to each other on the tape, it is possible to reduce the time required to rewind the entire tape when updating the index associated with file data recording, making it possible to construct an extremely easy-to-use system. It is possible.

Embodiment An embodiment in which the digital data recording and reproducing apparatus of the present invention is applied to a rotary head type magnetic recording and reproducing device will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a digital data recording/reproducing apparatus according to an embodiment of the present invention. This embodiment is applied to a so-called R-DAT type digital data recording and reproducing apparatus which records digital data by rotating two heads having different azimuth angles to form diagonal tracks on a tape.

In Figure 1, 1 is a cassette half, 2 is a renope 3
is a tape, 4 is a cylinder, s a + s b is a head for recording and reproducing, and 60.5 d is a head for reproducing and checking recorded data.
include. 7 is a mechanism control unit that controls the operation of the mechanism unit 6; 8 is connected to the heads 6a, 5b, 6c, and 5d and sends a recording signal or receives and receives a reproduction signal;
9 is an input/output device that receives and receives data from a host system (not shown) and sends reproduced data to the host system; 1o is an input/output device that performs data and recording signal conversion and error correction; This is a storage section that temporarily stores data input to the output device 9 and data to be exchanged with the signal processing section 8. Reference numeral 11 denotes a current position management means for managing the position of the head on the tape, and includes a register for storing a frame number. In this embodiment, two tracks recorded by a pair of heads sa and sb are treated as one frame, and each frame is managed by an absolute number assigned to each frame from the beginning of the tape. 12, when recording file data on a tape, sets the data to be recorded in the auxiliary recording section, such as file data and file management information, in the recording section 10 and performs recording according to instructions, or records file data and auxiliary recording data from the reproduced data. 13 is an index recording unit that records the file management information of each file recorded on the tape as an index at a predetermined position on the tape and also controls playback. playback control section,
Reference numeral 14 is an index recognition unit that identifies a portion where file data is recorded and a portion where an index is recorded.

The current position management means 11 , the file data recording/playback control section 12 , the index recording/playback control section 13 , and the index recognition section 14 are included in the file management control section 15 . The mechanism control section 7. The input/output device 9 and the file management control section 16 are connected to and controlled by a system control section 16 that controls the entire digital data recording/reproducing apparatus.

FIG. 2 is a diagram showing in which area each data is recorded when recording with the digital data recording/reproducing apparatus according to this embodiment. Although the tracks are originally formed obliquely to the tape running direction, they are shown here in a simplified manner as shown in the figure. The file data area occupies most of the tape, the main data area (file data recording area) records file data, and the sub data area (auxiliary recording area)
Information necessary for file management is recorded in.

An index section is provided near the beginning of the tape, an index section B is provided at the center, and an index section C is provided near the end of the data recording area, in which information for file management recorded on this tape is recorded.

Here, there are three index parts, index person, B
, C are provided, and the same content is recorded in each. An EOD area is provided at the end of the data recording portion to indicate that no data has been recorded since then. The auxiliary record section contains the file name, file creation (update)
Date and time, file attributes, frame position information (information on whether it is the first frame from the beginning of the tape), information indicating whether it is the beginning or end of the file, EOD flag (I
(information indicating that it is a COD area), an index flag (information indicating whether it is an index section or a file data section), etc. (see FIG. 3).

In the index section, create (update) a name for each file.
The date and time, management code, first frame number of the file, etc. are recorded (see Figure 4).

The operation of the digital data recording/reproducing apparatus configured as described above will be described next.

The digital data recording and reproducing apparatus in this embodiment receives data from a host system, records it on a tape, reproduces it, and sends the data to a host system. First, as an example of operation, a case where one file is additionally recorded will be explained.

When the power is turned on or a tape is set, an instruction is issued from the system control section 16, and management information regarding files recorded up to that point is read from the index section and stored in a part of the storage section 10 in advance. In each of the sub data areas of index sections A, B, and C, an index flag indicating that the index section is an index section and an index update date and time are recorded (see FIG. 3).

The system performs fast forwarding from the beginning of the tape using the high speed search mode, reads the information in the sub data area, and searches for the index flag. If an index flag is found, that part of the index data is read. Similarly, a search is performed in EOD area 1 indicating the end of data on the tape, and the latest index update date and time is set as index information. As an example of the information recorded in the index section, as shown in Figure 4, file name 1 creation (
Update) date and time, management code, first frame number of the file, etc. Next, data sent from the host system is received by the input/output device 9 and stored in the storage section 10. When a certain amount of data is accumulated, a command is issued from the system control section 16 to the file management control section 15. For example, considering the case where file X is to be added, it is known from the index information that it should be added after file W, so the tape is advanced after file W, that is, to the beginning of index section C. Since an absolute frame number is recorded in the sub-data area of each frame or track, the tape can be fast-forwarded while reading the frame number in the sub-data area by performing processing similar to the high-speed search of an audio DAT. This allows you to quickly feed the tape to the desired location. Then, the information (file name, etc.) to be recorded in the auxiliary recording section of the file data is set in the storage section 1o, and sent together with the file data to the signal processing section 8, where it is subjected to processing such as adding an error correction code and modulation. Sa.

At the same time, the system control unit 16 instructs the mechanism control unit γ to operate in the recording mode, and the mechanism control unit 7 controls the reel 2 and cylinder 4 to run the tape 3 and write the tape onto the tape. Record the data. Thereafter, the index information stored in the storage unit 10 is updated based on the management information of the newly added file X, and is subsequently recorded as an index section C, and the index information on the tape is also updated.

Also, consider a case where file E must be updated and index information must also be updated. When file E is updated, by comparing the current position frame number of the head with the frame number indicating the position of each index section obtained from the index information, the nearest index section is found and the index section Bi is updated. . For example, when the update of file E is completed, current position management means 1
Assume that the current frame number managed by 1 is "44a". The first frame number of each index section is
From the index information shown in Figure 4, we know that the index is l'-ooolJ, the index B is "513J, and the index C is [1212J," so by calculating the difference from the current position, index B is the closest index part. As a result, there is no need to spend time rewinding the tape from the end to the beginning in order to update the index section, and a system with good operability can be provided.

In addition, by arranging multiple index sections in this way, there is no need to rewrite and update the same index section every time one file is recorded, and the number of accesses to one index section is reduced, improving reliability. It has the effect of

Furthermore, as shown in Figure 6, if the tape is divided into several parts (hereinafter referred to as volumes) and each volume has an index section for each volume, the files near the files to be added or updated can be Due to the presence of the index section, updating the index section does not take a long time and is easy to operate, similar to the @ entry.

If the configuration is such that the number of updates of the index section is also recorded, when the number of updates exceeds a preset number within the range where reliability can be guaranteed, the recording position of the index section can be changed and recorded at a different location. , the index section can be secured elsewhere with high reliability before the tape deteriorates.

Note that some of the mechanism control section 7, current position management means 11, file data recording/playback control section 12, index recording/playback control section 13, index recognition section 14, file management control section 16, system control section 16, etc. It can also be integrated and configured with a microcomputer.

Effects of the Invention As described above, the present invention provides a digital data recording/reproducing device for recording and reproducing a plurality of files containing logically connected data on a single tape, in which the recording/reproducing means is A current position management means for managing the position on the tape, a file data recording and playback control means for controlling the recording and playback of file data, and recording of an index that is management information for each file recorded on the tape. index recording and reproduction control means for controlling reproduction; index recognition means for identifying a portion where file data is recorded and a portion where an index is recorded; the current position management means; the file data recording and reproduction control means; and the index recording and reproduction. By providing a file management control section that controls the control means and the above-mentioned index recognition means, there is no need to specify the location of the index, making it possible to build a flexible system configuration, and making it possible to easily access frequently accessed index parts. By dividing or arranging a plurality of tapes, it is highly effective in preventing deterioration of only specific portions of the tape and ensuring sufficient reliability.

Further, by arranging file data and an index section related to the file data close to each other on the tape, it is possible to construct a system with extremely good operability even when updating the index accompanying recording of file data.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a digital data recording/reproducing apparatus in an embodiment of the present invention, and FIG. 2 shows the positional relationship of each file and index section recorded on a tape in an embodiment of the present invention. Fig. 3 is a state diagram showing an example of information recorded in the auxiliary recording section, Fig. 4 is a state diagram showing an example of information recorded in the index section, and Fig. 6 is a state diagram showing an example of information recorded in the auxiliary recording section. FIG. 2 is a schematic diagram illustrating an example of dividing and managing a volume into several volumes. 1...Cassette half, 2...Reel, 3...Tape, 4...Cylinder, 6
a, 5 b, 5 c, 5d...head,
6... Mechanism section, End... Mechanism control section, 8... Signal processing section, 9... Input/output device, 10... Memory Part, 11...
Current position management means, 12... File data recording and playback control unit, 13... Index recording and playback control unit, 14... Index recognition unit, 15.
...Film management control unit, 16...System control unit. Name of agent: Patent attorney Toshio Nakao and 1 other person -+
, ni-ko・, 1 bit and Fig. 4

Claims (4)

[Claims] (1) Recording and reproducing means for recording and reproducing a plurality of files containing logically connected data on a single tape, and the position of the recording and reproducing means on the tape. A current position management means for managing, a file data recording and reproduction control means for controlling recording and reproduction of file data, and an index recording and reproduction control means for controlling recording and reproduction of an index which is management information of each file recorded on the tape. and index recognition means for identifying the part where the file data is recorded and the part where the index is recorded, the current position management means, the file data recording and playback control means, the index recording and playback control means and the index recognition means. 1. A digital data recording/reproducing apparatus, comprising: a file management control section for controlling the index; (2) The digital data recording/reproducing apparatus according to claim 1, wherein the portion on which the index is recorded is divided into a plurality of blocks and arranged on the tape. (3) The digital data recording/reproducing apparatus according to claim 1, wherein a plurality of indexes having the same contents regarding files recorded on the tape are arranged. (4) The tape according to claim 1, wherein the tape is managed by dividing it into several parts, and an index of contents related to the files recorded in each part is arranged in a part of or near each part. Digital data recording and reproducing device.