JPH03266247A - Recording and reproducing device for magnetic tape - 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 Industrial Application] The present invention relates to a digital magnetic recording and reproducing device that records and reproduces digital signals of data and transmits and receives data to and from an upper-level device.

[Conventional technology]

Since the conventional device is for audio use,
As described in Publication No. 3-49627, although the tape is protected from scratches due to damage to the magnetic tape due to sudden braking during high-speed driving, consideration is given to data protection such as insufficient data recording due to recording malfunction etc. It has not been.

[Problem to be solved by the invention]

The above conventional technology does not take into consideration the point of controlling the recording stop when the leader tape is reached and recording becomes impossible while recording digital data on the magnetic recording tape, and there is a problem in that insufficient recording of data occurs. Ta.

An object of the present invention is to detect a position within a predetermined tape length (hereinafter referred to as EOT) before reaching a leader tape while a magnetic tape is running.
To provide a recording shortage prevention control device during automatic format data recording, which automatically determines the tape length to be used based on an EOT alarm and formats the maximum number of frames during formatting operation. It is in.

Another object of the present invention is to notify a host computer of an EOT alarm during tape running.

Furthermore, the predetermined tape length for detecting an EOT alarm is made variable to improve usability on the host side.

[Means to solve the problem]

The above purpose is calculated based on the number of rotations of the reel when the tape is running, and reaches a predetermined position from the end of the tape (EOT).
This is achieved by detecting alarms).

In addition, in order to perform automatic formatting, the microprocessor must have information on the maximum number of frames according to the tape length, and based on the comparison result of the frame number at the time the EOT alarm was generated and the maximum number of frames, the maximum number of frames can be reached. It is designed to perform formatting operations.

Furthermore, in order to prevent insufficient data recording during access, if an EOT alarm is detected during recording,
It performs a control operation to stop the recording operation and notifies the host computer of this result.

Furthermore, in order to match data processing on the host computer side, the predetermined tape length for generating an EOT alarm can be changed by external input.

[Effect]

The number of rotations of the reel changes depending on the number of turns of the tape. Therefore, by calculating the remaining tape length from the reel rotation speed information and the reel diameter, it is possible to issue an EOT alarm at the position of the specified tape length from the leader tape. The number of remaining frames is calculated based on the frame M information at the time of occurrence.

As a result, during the formatting operation, it is possible to obtain information on the number of remaining frames relative to the maximum number of formats on the tape being used, so that automatic formatting can be performed. Also, during sequential access, data recording stop control and EO to the host computer can be performed based on the information on the number of remaining frames.
By issuing the T alarm notification, insufficient recording of data can be prevented.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a block diagram showing an embodiment according to the present invention.

In FIG. 1, reference numeral 1 denotes a magnetic recording/reproducing device, which is comprised of the following components. That is, 2 is a rotating drum, and a pair of recording heads 6 are placed opposite to this rotating drum 2.
A pair of reproducing heads 7 are arranged to face each other, and the line connecting the recording heads is perpendicular to the line connecting the reproducing heads. By rotating the rotating drum 2 at high speed, high density recording is achieved on the magnetic recording tape 5. Digital data signals can be recorded and played back. Furthermore, this recording signal is recorded in such a way that two inclined tracks are formed by one rotation of the rotary drum 2, and these two inclined tracks are regarded as one frame, and the digital signal is completed within this one frame. coded and recorded. 5 is a magnetic recording tape for recording this recording signal, 8 is a reel for fixing and rotating the magnetic recording tape 5, and 3 is a capstan for controlling the speed of the magnetic recording tape 5 while it is running.

4 is a brake solenoid that applies brakes to the reel, 1
2 is a capstan control circuit that controls the capstan 3; 13 is a control circuit that controls the reel 8; 10 is a circuit that controls the brake solenoid 4; 11 is a signal that adds error detection and correction signals to the recorded signal; Recording signal processing circuit that performs modulation of the signal;Reproduction processing circuit that demodulates the signal reproduced from the rotating drum 2 and detects and corrects errors. 9 is a recording/reproduction processing circuit 11. Capstan control circuit 12. This is a microprocessor that controls the reel control circuit 13 and the brake control circuit 10 and performs arithmetic processing. 14 is a host device such as a personal computer that predominantly uses a magnetic recording/reproducing device. 15 is an interface connection path with an external device. 16 is a key input circuit of this device.

First, when a data recording or reproduction command is sent from the host device 14 to the microprocessor 9 via the interface circuit 15 in the magnetic recording device 1, the brake solenoid 4 is released and the reel 8. By controlling the capstan 3, the running speed of the magnetic recording tape 5 is maintained at a specified speed, and the recording/reproducing circuit 1
1, data is recorded and reproduced by the rotating drum 2.

A method for detecting an EOT alarm will be explained using FIG. The reel 8. When the tape starts running by the capstan 3, calculation of the remaining length of the tape is started. The calculation method in this example is that the number of turns n, where the hub rotation period of the magnetic recording tape is T, the hub diameter is r, the tape thickness is t, and the tape speed is V, is n = (T ・V/W -r)/2 t, and the remaining tape length is expressed as n=n-yr (T-v/π-r)/2. Therefore, the predetermined tape length data that has been set is compared with the overflow, and when they match, an EOT alarm signal is output.

The method for calculating the tape length used in this embodiment will be explained based on FIG. There are several types of recording tapes for DAT-MS with different tape lengths, and it is necessary to make a distinction between them. Therefore, in this embodiment, the tape format is such that two inclined tracks as shown in FIG. 2 are formed by one revolution of the rotating drum, and these two inclined tracks are defined as one frame. Because of this,
When the rotating drum rotates at magneto rpm, a 46-minute tape has a round blade magneto frame, and a 60-minute tape has a No. 12 frame.

It is possible to record 100,000 frames on a 90 minute tape and 240,000 frames on a 120 minute tape. Furthermore, an area for recording the absolute frame level is provided within the SVB code area within the track. Therefore, the length of the used tape is determined based on the absolute frame level at the time the EOT alarm is detected.

The automatic formatting operation will be explained based on FIG. Tape format command from host device (step 301)
starts tape formatting (step 302
). Next, an EOT alarm check is performed (Step 303). If no EOT alarm is detected, the formatting operation is continued. If an EOT alarm is detected, the tape length to be used is determined and data for the maximum number of frames is set (Step 3).
04). Next, the remaining frames are formatted based on the set data (step 305), and the automatic formatting operation is ended (step 306).

The recording operation in the access mode will be sequentially explained using FIG. 4. Data recording is started in response to a data recording command (step 401) from the host device (step 402).
). Next, perform an EOT alarm check (step 4).
03) If not detected, the recording operation continues, and if detected, the length of the tape used is determined and data for the maximum number of frames on the tape used is set (step 404). Next, the remaining frames are recorded for the maximum frame number data (step 405), and the recording operation is stopped (step 406).

The transmission of EOT alarm information to the host will be explained using FIG. When the microprocessor 9 detects the EOT alarm, simultaneously with these operations, it is detected and sent to the host computer 14 via the interface circuit 15, and data on the number of remaining frames is sent. Based on this information, the host side processes the transmitted data. Further, the specified tape length, which is the detection position of the EOT alarm, can be changed by the key 16 according to the processing capacity and processing method of the host side.

〔Effect of the invention〕

According to the present invention, since the position of the specified tape length can be detected from the leader tape of the data recording tape (EOT alarm), the type of tape length to be used can be determined, and the operation procedure by the tape length side on the host side can be determined. Effective for simplification.

Furthermore, automatic formatting of the recording tape is possible by determining the tape length, and the formatting of the number of recordable frames of the tape used can be automated. Furthermore, during the sequential recording operation, recording can be stopped before the leader tape, which has the effect of preventing insufficient recording of data.

Furthermore, since the EOT alarm signal and data on the number of remaining frames being recorded can be sent to the host side, data processing on the host side can be made more efficient. Furthermore, since the detection position of the EOT alarm can be changed, data such as the EOT alarm can be sent to the host side according to the processing capacity of the host side.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is a data format diagram of this embodiment, Fig. 3 is an operation flowchart during formatting operation, and Fig. 4 is an operation flowchart during data recording operation. . 1... Magnetic recording/reproducing device 2... Rotating drum 3... Capstan 4...
・Brake solenoid 5...Magnetic recording tape 6...Recording head 7...Playback head 8...
Reel 9...Microprocessor 14...Host computer 16...Key human interface circuit Sono

Claims (1)

[Claims] 1. Two inclined tracks are formed by one rotation of a rotating drum equipped with a pair of recording heads and a pair of reproducing heads, and the two inclined tracks are regarded as one frame,
A frame number is assigned to each frame, and the digital signal is
In the magnetic tape recording/reproducing device that encodes the digital signal so as to be completed within one frame and accesses the digital signal directly and sequentially, the recording position on the magnetic tape is located within a predetermined tape length from the tape end. 1. A magnetic tape recording/reproducing device characterized by being provided with means for detecting that a position within the range is reached. 2. In claim 1, the detection means detects the number of revolutions of the supply reel motor, and when the number of revolutions of the supply reel motor becomes larger than a predetermined value, a predetermined tape length from the tape end is detected. A magnetic tape recording/playback device that detects when a position within the range is reached. 3. In claim 1, information on the maximum number of frames that can be recorded according to the length of the magnetic tape is stored in the memory of the control microcomputer, and during formatting operation, the frame number at the time when the EOT alarm is detected and the maximum number of frames that can be recorded according to the length of the magnetic tape are stored. The magnetic tape device automatically determines the magnetic tape length by comparing the length of the magnetic tape with the number of frames, and performs a formatting operation up to the maximum number of frames that can be recorded with the magnetic tape length based on the determination result. 4. The magnetic tape device according to claim 1, wherein when an EOT alarm is detected during a recording operation in sequential access mode, the host computer is notified of the detection of the EOT alarm after the recording operation is completed. 5. The magnetic tape device according to claim 1, wherein the length of the predetermined magnetic tape from the EOT for detecting the EOT alarm is variable.