JPS59146466A - Magnetic tape recorder - Google Patents

Abstract

PURPOSE:To have the shortest time for execution of the next expected instruction by using a control means which reads automatically the recorded or reproduced information block in the opposite direction if an error is detected with said information block. CONSTITUTION:When an advance instruction is given to a control circuit 17 while a tape is stopped at a point P1, the circuit 17 moves the tape forward. Then a block 2 is recorded and reproduced when the tape reaches a point P2. Then the tape is shifted to a point P3 or the tape waits for the next instruction until the tape reaches the next block 3. When the next advance instruction is given during this period, the tape moves to the block 3. If no instruction is given, the tape is moved back to check whether an error is detected in the preceding action when the tape reaches a point P5 where the block 2 can be read out in the move-back direction. When no error is detected, the traveling of the tape is stopped to wait for the next instruction at a point P1'. If an error is detected, the block 2 is read out while moving back the tape. When this reading is over, the tape 1 is stopped to wait for the next instruction at the point P1. Here if a move-back instruction is gien, the circuit 17 sends immediately a report telling that the move-back instruction is already through. Thus the circuit 17 waits for the next instruction.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic tape recording device, and more particularly to a magnetic tape recording device for information processing.

Conventionally, in magnetic tape devices that do not start or stop within the IBG, such as the reel-to-reel direct drive method, the first
As shown in Figure (a), the cheater block 2 on the magnetic tape 1 can be written or read in the direction of the arrow, and the magnetic tape is further driven in the opposite direction from the stopped point P4 until it stops at the point PI', where the next The method was to wait for orders. According to this method, if the next command is an instruction to run the magnetic tape in the same direction as the previously executed command, it will run from point P 1 / in the direction of the arrow as shown in Figure 1(a). Then the next cheater block 3 can be written or read. previous block 2
If no error is detected during writing or reading, the next command given will be a command to write or read data block 3, which is correct in most cases, considering the general usage of magnetic tape devices. This method can be expected to reach the next block 3 in the shortest time. However, if an error is detected during loading or reading of the previous block 2, an instruction is usually given to run in the opposite direction to the previous instruction in order to re-load or read out the block 2 again. In this case, according to the conventional direction, the first
As shown in Figure (b), drive 1. ...: After stopping at point P4, drive in the opposite direction to indulge in the previous table 1-table 2 and output 1, so it is not possible.

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■ ・□ − Eliminate the shortcomings in the position and then: Implementation of the predetermined command □
The object of the present invention is to develop a magnetic tape device designed to minimize the processing time.

According to the invention, in a magnetic tape recording device that records information on a magnetic tape and takes full advantage of the axes of magnetic tape, a certain laboratory reproduced information by recording information in nm.
11. A magnetic tape recording device is provided which is characterized in that it has means for dynamically controlling the information block to be read backwards in the event that an error occurs in the information block. .

Next, an embodiment of the invention will be described with reference to the drawings.

Fig. 2 shows a magnetic tape recording device according to an embodiment of the invention.◇In Fig. 2, the embodiment of the invention drives the magnetic tape l directly by a supply reel 1''0 and a take-up reel 11. Information is recorded on the magnetic tape 1 by a reel-to-reel W contact drive type magnetic tape recording device. The 1-inclusive circuit 1.3 and 1. that drives the magnetic tape information is transferred to the IF,
It includes a reproduction circuit 14 for converting into a ``L'' and a readout circuit 15 for restoring information from the electrical signal and detecting errors, and is further arranged in contact with the magnetic tape IK,
An encoder 16 that rotates as the magnetic tape runs and generates signals corresponding to the running speed and distance;
-4+ reel motor and 1. Write 1 path 13 and 1. The reading circuit 15 includes a control circuit 17 that controls the readout circuit 15. .

This control circuit 17 returns the magnetic tape to the take-up reel 11 in the opposite direction in the same manner as in the past when no error is detected when writing or reading information to or from the magnetic tape by the read circuit 15. Next, when a command to run the magnetic tape in the same direction is given, the magnetic tape is stopped at the optimal position for writing or reading the next information block. In addition, when an error message is detected on the information prompt, the control circuit 17 reads the information block in which the error occurred in the reverse direction and then stops it.1. Next, when a rewrite or reread command is given from a host device, it is controlled so that the command can be executed in a short time.

1, the circuit y3 receives write data from the host device (b) and sends it to the magnetic head 12. The input signal from the control circuit 17 is controlled as shown in FIG. ．． Send 7 data and read 1
If an error occurs in the output data, the control circuit 17 is controlled to send out an error signal the next time.

Figure 1 (C) shows the running state of the magnetic tape in a non-example, with the horizontal axis showing the moving distance of the magnetic tape and the vertical axis showing the tape running speed. ), the magnetic strip 1 is an information block 2 in which information is recorded on the tape. ．． 3'z
Each point P has a magnetic tape 1. 0 magnetic, which shows the positional relationship between the magnetic head and the magnetic head: tape 1 point p1, p
1' and P4 and stopped. condition, 4b
, from point P,1 to P2, and is in a state of being accelerated in the forward direction. Furthermore, the magnetic tape is shown to be running forward at a constant speed at points P2 and P3, and at point P5.
, the vehicle is traveling at a constant speed in the opposite direction.

...□ In particular, Pl is the initial stop position or the stop after writing or reading block 3 in the backward direction, P2 is the writing or reading start position of block 2, and P3 is the stop position after writing or reading block 3 in the backward direction.
P4 is the stop position after writing or reading block 2, P5 is the deceleration start position in the backward direction, and Pi' is the final stop after writing or reading block 2 in the forward direction. position, P2' is block 3
is the writing or reading start position in the forward direction.

The operation of one embodiment of the present invention will be described with reference to the control flowchart of FIG.

Here, the movement of the magnetic tape 1 from the supply reel 10 to the take-up reel 11 side is defined as "forward 2", and the movement in the opposite direction to the magnetic tip is defined as "1 backward".

Assume now that the forward command from the higher-level device has already been successfully completed, and the machine is stopped at point 11 in Figure 1 (C), waiting for the next command. This corresponds to step 20 in Figure F)73. At this point, a forward command is applied to the control circuit 17,
The control circuit 17 drives the supply reel l-1 (1) and the take-up reel 11 in the forward direction. The running speed of the tape becomes a steady speed, and the magnetic tape reaches the P2 point in Figure 1 (C).
The readout gate is opened and the readout circuit 13 and readout circuit 15 are started to record and reproduce information. When they are completed, the control circuit 17 reports the completion to the host device based on the month of completion.

Thereafter, the control circuit 17 either sends the magnetic tape through the entire information block 2 to a predetermined distance, that is, to point P3, or issues intermittent commands until it reaches the next information block 3. wait to be given. During this time, if the next forward command is given, the control circuit 17 will not stop and will read or write the next information block 3, but if no command is given, it will stop for a lifetime (it will continue to move backward after -). When the previous information block 2 reaches point P5 where it can be read in the backward direction, it is checked whether the error has been corrected during the previous loading or reading.Furthermore, the control circuit 17 determines that there is no error and tl is constant. The line is stopped and the next command is issued at the PI 3 point in FIG. 1(c).

Further, when there are 41 errors on the magnetic tape, the control circuit 17 reads out the information block 2 while running the magnetic tape in the backward direction, and after reading the information block 2, stops the magnetic tape 1 completely and reads the first information block.
Next instruction 2 at point P1 in figure (c)? ='r ft
11. Control. This corresponds to step 21 in FIG. Here, when the control circuit 17 receives the retreat command, since the execution of the command has already been completed 2, it immediately returns a completion report to all higher-level devices. After that, a forward command is given and the control circuit 17 advances from the 121st point to the previous information block 2.
f $f, include or bo [, get excited.

As explained above, the present invention has the effect of completely reducing the time required for the operation of the magnetic IP device by switching the control procedure depending on whether there is an error when reading ν4 or l''i and reading 1.

[Brief explanation of drawings]

Figure 111 shows the relationship between 1 magnetic tape + block 1 cock and magnetic tape + 1 message J return - 11 river and distance.
a) is a conventional magnetic voop device, and when a forward command is given for a certain period of time after execution of a forward command, the state shown in Fig. 1 (
b) l<''i If a backward command is given after a certain period of time after executing a forward command in a conventional magnetic tape device, the
c) is a diagram showing the operation of one embodiment of the present invention, and FIG. 2 is a diagram showing the operation of an embodiment of the present invention. ! FIG. 3 is a flowchart showing a control procedure in a control circuit according to an embodiment of the present invention. 1. Magnetic tape, 2,3 ゛°information block・10
・ Supply reel, 11... Take-up reel, 12
... Recording head, 13 - Sliding circuit, 14 - Playback head, 15 ... Readout 7-way, 16 - Encoder, 17 ... Control circuit / 2.3 Foil 71 E 7 Active 2 hard

Claims (1)

[Claims] In a magnetic tape recording device that records information on a magnetic tape and reproduces information on a magnetic tape, if there is an error in the information plotter that recorded the information or reproduced the entire information, control is performed so that the information block is not read in the reverse direction. What is claimed is: 1. A magnetic tape recording device characterized by having means for.