JPH04159645A - Retrieving method for end mark of data recorder, and recording and erasing method for mark for end mark warning - Google Patents

Abstract

PURPOSE:To improve the reliability of data by a method wherein an end mark warning mark is recognized. CONSTITUTION:When a tape cassette is inserted into a data recorder 1, an end mark warning mark is searched with a high speed about 200 times and its absolute address is memorized and the searching speed is gradually reduced to (n) times so as not to damage a tape and, further, reduced to one-time speed from a point of (m) frames before an end mark and the end mark is recognized and its absolute address is memorized. After end mark warning mark is searched, the tape speed is gradually changed to avoid the tape damage. The end mark warning mark is renewed every time of data recording. The warning mark is recognized by reverse direction low speed search and the tape is stopped immediately before the warning mark once and then the mark is erased by sub-code after-recording. With this constitution, sudden braking to stop at the record end is not necessary and the reliability of data can be improved.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention relates to a method for searching an end mark in a computer external storage device (data recorder) using a rotating head type magnetic recording/reproducing device such as R-DAT, and an end mark. Concerning how to record and erase warning marks.

(B) Conventional technology Traditionally, R-DAT uses a rotating head to form tracks on a tape, and divides main information such as music, ATF information for tracking, and subcode information used for searches into areas. and recorded. In the subcode information, an end mark indicating the end of the recording area is recorded over 300 frames, and when recording continues from the end of the recording on a tape with an end mark recorded, the end mark is set at 200 frames. The conventional method was to perform a search twice as fast as possible, stop the recording at the end position, and start recording immediately.

To explain with reference to the flowchart of FIG. 6, the end mark is searched for at a speed of about 200 times, and stopped at the same time as it is confirmed. After that, it performs a slow search in the reverse direction to find the beginning of the end mark and then stops.

Regarding the end mark of such R-DAT, Japanese Patent Application Laid-Open No. 1-273254 (GIIB151087)
There are some suggestions.

(c) Problems to be solved by the invention However, when performing a high-speed search for end marks,
As shown in the figure, when the end mark is detected, the brake is applied suddenly to stop the tape, but in this case, tape damage is large, and the data reliability is particularly important in data recorders using R-DAT. This will destroy the reliability of the data.

(d) Means for Solving the Problems The present invention is intended to solve the above problems, and includes recording an end mark at the recording end point and storing the absolute position, and ending the recording at a predetermined frame before the absolute position. An end mark recording method for a data recorder is proposed, which is characterized by recording a warning mark. In addition, in the high-speed end mark search, the end mark warning mark is first searched at high speed, and at the same time, the search speed is reduced to a low speed.
This paper proposes an end mark search method for a data recorder, which is characterized by searching for an end mark using the following methods.

(E) Effect With the above configuration, in a high-speed search for an end mark, the search speed can be gradually reduced before the end mark.

(F) Embodiment Next, a method for recording an end mark in the data recorder of the present invention will be explained.

In Figure 1, (1) is a data recorder using DAT, which is formed by one rotation of a rotary cylinder (4) to which recording/reproducing heads (2) and (3) are attached 180 degrees apart. Data is recorded and reproduced on the magnetic tape (5) in groups, with two inclined tracks arranged as one frame and a predetermined number of frames as one group. In the figure, a data recorder (1) is connected to a host computer (7) via an interface bus (6). (8) is a hard disk which sends and receives data to and from the interface control circuit (9) in the data recorder (1) via the bus (6) according to instructions from the host computer (7). (10) is a DMA that manages the buffer memory (11), (12) is an ECC circuit that performs error correction such as parity on data stored in the buffer memory (11), (13) is a reproduction amplifier, ( 14) is a recording amplifier, (15) is a recording/reproduction switching circuit, (16) is a mechanism control circuit controlled by a microcomputer (17), and (18) is a signal processing circuit.

Hereinafter, an embodiment of a method for recording an end mark warning mark at the time of ejection of the data recorder having the above structure will be described with reference to the 70-chart in FIG. 2 and the diagram showing the tape speed in FIG. 3.

First, when eject is commanded (step 1), move 200 frames before (2Xn) from the absolute address where the end mark is recorded, that is, the absolute position (A!.D) of the last recording track.
Confirm by performing a high-speed search (steps 2 and 3)
, then shifts to n times slower search and when the absolute position is (m+n) frames before AEoD (steps 4 and 5
), the playback gradually becomes 1x speed (step 6), and when the absolute position becomes n frames before the AEOD, the subcode area becomes dubbing and an end mark warning mark of 300 frames is recorded (step 7). Next, the mode shifts to n times slower search again, and when the absolute position becomes m frames before the absolute position A Eo (step 8.9), the playback gradually shifts to 1x speed (step 10), and the absolute position becomes A□. When it becomes 0, the end mark of 300 frames is recorded as an after-recording of the subcode area (step 11). Finally, the tape is rewound to the beginning (step 12) and ejected (step 13).

Next, an embodiment of a method for searching for an end mark warning mark when inserting a cassette will be described with reference to the flowchart of FIG. 4 and the diagram of FIG. 5 showing the tape speed when inserting a tape.

First, when a tape cassette is inserted into the data recorder (18) (step 14), the end mark warning mark is confirmed by a high-speed search of about 200 times in steps 15 and 16, and the absolute address ( A
□0Dn), and to avoid damaging the tape, the search gradually moves to n times slower speed (step 18), and from m frames before the end mark, the search gradually becomes 1 times faster (
Step 19) Check the end mark Step 20
), its absolute address AEoD is memorized (step 21
). The changes in tape speed so far are shown in FIG. 5, and after searching for the end mark warning mark, the tape speed is changed gradually to avoid tape damage.

Furthermore, since the end mark is updated every time data is recorded, it is necessary to erase the end mark warning mark, and this process will be described below. A low-speed reverse search is performed (step 22) to confirm the end mark warning mark (step 23), and the process is temporarily stopped just before the end mark warning mark (step 24), and is erased by subcode dubbing (step 25).

Through the above-described operations, it is possible to record an end mark warning mark, to reduce the search tape speed by checking this warning mark, and to erase this warning mark.

(G) Effects of the Invention According to the present invention, when searching for an end mark at high speed, the tape speed can be reduced by checking the end mark warning mark a predetermined frame before the end mark. There is no need to apply sudden brakes, damage to the tape can be suppressed, and data reliability can be improved, so it is extremely useful for use in a high-speed end mark search method for data recorders using R-DAT. be.

[Brief explanation of drawings]

Fig. 1 is a schematic block diagram for explaining the present invention, Fig. 2 is a schematic block diagram for explaining the present invention;
3 and 4 are flowcharts for explaining the present invention in detail, and FIGS. 3 and 5 are diagrams showing the tape speed of the embodiment of the present invention. FIGS. 6 and 7 are flowcharts showing a conventional search operation and diagrams showing the tape speed thereof. (16)...mechanism control circuit, (17)...
microcomputer,

Claims (3)

[Claims] (1) An end mark search method for a data recorder characterized by checking the end mark warning mark in a high speed search and at the same time reducing the search speed to a low speed to search for the end mark. (2) An end mark warning mark recording method for a data recorder, which comprises recording an end mark warning mark a predetermined frame before the absolute position of the end mark. (3) The feature is that the end mark warning mark is confirmed by high-speed search, and at the same time, the search speed is reduced to low speed to search for the end mark, and then the end mark warning mark is confirmed and erased by reverse low-speed search. How to erase the end mark warning mark on a data recorder.