JPH0432070A - Recording method for data recorder - Google Patents

Abstract

PURPOSE:To keep the secret of personal data by recording meaningless data following an end signal of the end of data recording up to the end of a tape or already recorded data. CONSTITUTION:After the end signal having a prescribed length is recorded at the time of the end of data recording, meaningless data is recorded following this end signal up to the end of the tape or already recorded data when unnecessary already recorded data exists after the end signal. Data received from a bus 5 is stored in a buffer memory 10, and data required to constitute a group is added to this data by a microcomputer 9, and an error correction code is added to each group by an error correcting circuit 12. Thus, the secret of personal data is kept because unnecessary already recorded data can be physically erased after additional recording of new data.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a data recorder that uses an R-DAT as a storage device for information equipment.

(B) Conventional technology Conventionally, when recording data with a data recorder using R-DAT, an end signal is recorded at the end of the recording, and the next time recording is performed, a high-speed search is performed to end the data recording. The method used was to detect the signal and then make additional recordings from that position. However, in general, additional recording is not necessarily performed from the end position of data; for example, when data is no longer needed, the user may perform additional recording from the middle of the data that is no longer needed. In this case, if the newly added data recorded is shorter than the data that is no longer needed, unnecessary existing data will remain after the end signal added at the end of recording of the new data, but Since the data existing after the end signal added at the time is logically defined as inaccessible, there is no problem in practice.

(c) Problems to be solved by the invention However, although the unnecessary existing data after the end signal is considered to be logically erased, it is not physically erased, and there is some way to erase it. There is a possibility that the contents of the data can be read, and there is a problem in terms of maintaining the confidentiality of personal data.

(d) Means for Solving the Problems In view of such problems, the present invention records an end signal of a predetermined length at the end of data recording, and when there is unnecessary existing data after the end signal, The present invention proposes a recording method for a data recorder in which, following this end signal, unnecessary data is recorded up to the end of the tape or the end of existing data.

(E) Effect According to the present invention, if existing unnecessary data exists after the end signal recorded after the recording of new data is completed, the unnecessary data is recorded until the end of the tape or the end of that data. Therefore, it acts to physically erase existing unnecessary data by overriding it.

(f) Example An embodiment of the present invention will be described below with reference to the drawings.

In Fig. 1, (1) is a data recorder using R-DAT, and rotating heads A (2) and B (3) are 180 mm.
One frame is two inclined tracks formed by one rotation of cylinders (4) installed at intervals, and one group is a predetermined number of frames, and digital data is recorded and reproduced in groups. This is what I did. In the figure, this data recorder (1) is connected to a host computer (6) via an interface bus (5). Here, the interface bus may be of the 5C5I standard, for example.

During recording, data in the hard disk (7) is sent to the data recorder (1) via the bus (5) according to instructions from the host computer (6).

In the data recorder (1), a microcomputer (9) that controls the operation of the data recorder, a DMA (11) that controls the buffer memory (10), and a bus (5) are connected via an interface control circuit (8). Data and control signals are exchanged between them.

The data received from bus (5) is transferred to DMA (11
) is stored in the buffer memory (10). Since data is recorded and reproduced in groups, the data necessary to form a group (information regarding data contents, hereinafter referred to as INDEX information) is stored in the buffer memory (10) in a micro added by the computer (9) and also the error correction circuit (12)
An error correction code is added to each group.

Thereafter, the data in the buffer (10) is transferred to the signal processing circuit (1).
In step 3), according to the audio DAT format, error correction codes are added, interleaved, etc. Recording is performed on the tape (16) by the recording and reproducing rotary heads A (2) and B (3). Also, at this time, the microcomputer (9)
Sub-information (sub-code data) regarding the recording data is created and recorded in the sub-code area on the track.

During playback, heads A (2) and B (3) are played from tape (16).
) The signal reproduced by the recording/reproducing switching circuit (15)
, a reproduction amplifier (17), and is subjected to de-interleaving, error correction, etc. in a signal processing circuit (13), and then stored in a buffer memory (10). and an error correction circuit (
12), errors are corrected in groups, and after the INDEX information added during recording is removed, the DMA
(11) and the host computer (via bus (5))
6). Note that (18) is a mechanism control circuit that controls the mechanism of the data recorder (1) under instructions from the microcomputer (9).

Next, the recording operation in the data recorder (1) will be described below with reference to the tape pattern in FIG. 2 and the flowcharts in FIGS. 3(a) and 3(b).

In Figure 2 (a), (DI) (D2) (D3) (D4
) (D5) indicates valid file data recorded on the tape (16), an end signal of a predetermined length is recorded after the file data (D5), and furthermore, after the end signal, an end signal of a predetermined length is recorded. are the above five file data (Dl) ~
There is some invalid data recorded before recording (D5), that is, an undefined signal, and there is a no-signal area from after the undefined signal to the end of the tape.

In this tape (16), Fig. 2 (b) (C) (d
), when new data (D6) is additionally recorded after the file data (Dl), the host computer (
As soon as the recording end command (step 1) is received from 6),
A period in which the end signal can be detected by high-speed search (for example, 300
frame) is recorded (step 2).

At this point, it is determined whether unnecessary data needs to be physically erased based on instructions from the host computer (6) or internal switch settings (step 3). If there is no need to perform physical erasure, the recording operation is ended, and if physical erasure is necessary, recording of irrelevant data is started (step 4) and recording is continued until the end of the tape (step 5). Figure 2(b) shows the existing file data (D4) which becomes unnecessary data after the new end signal.
Figure 2 (C) shows the tape pattern when D5) and the following end signal and indefinite signal are not physically erased.
is a tape pattern in which, following the new end signal, unnecessary data is recorded up to the end of the tape, and unnecessary data is physically erased by overwriting, according to the flowchart of FIG. 3(a).

In addition, a playback head that traces the tape (16) in advance of the recording head is attached to the cylinder, and the presence or absence of a signal on the tape is determined from the output level of the playback head prior to recording. It is also possible to override only the signalless area with meaningless data, and in this case, it is possible to save the effort of overriding the no-signal area with meaningless data.

At this time, following the flowchart shown in FIG. 3(b), it is possible to record the unexpected data up to the end of the existing data following the new end signal as shown in FIG. 2(d).

(g) Effects of the Invention As described above, according to the present invention, when new data is additionally recorded on top of unnecessary existing data and subsequently a new end signal is recorded, the Since unnecessary existing data can be physically erased by overriding it with unnecessary data, it is particularly effective in cases where confidentiality of personal data is required, such as in data storage devices for information equipment. .

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a data recorder for realizing the recording method of the present invention, and FIGS. 2(a) to (d)
3A and 3B are tape pattern diagrams for explaining the recording method of the present invention, and FIGS. 3(a) and 3(b) are diagrams showing flowcharts for explaining the recording method of the present invention. (1)...Data recorder, (5)...Bus, (6
)...Host computer, (7)...Hard disk, (9)...Microcomputer.

Claims (1)

[Claims] (1) Recording of digital signals on a tape that is helically scanned by a rotating head, with two tracks as one frame.
A data recorder that records a plurality of frames in units of groups as one group, and is characterized in that following a termination signal after data recording is completed, unexpected data is recorded to the end of the tape or to the end of existing data. How to record.