JPS5938952A - Control system of magnetic tape - Google Patents

Abstract

PURPOSE:To improve the efficiency of an information processing system, by processing a skip file instruction having a comparatively long processing time in a high speed mode with no intervention of an upper device. CONSTITUTION:An upper device 30 outputs a skip file instruction to a magnetic tape device MTC31, and the MTC31 outputs a skip file indicating signal to a magnetic tape device MTU32 by the skip file instruction. The MTU32 stores the speed that is not equal to the highest level under the present processing among plural processing speeds, then performs automatically a skip file action in the highest active mode of the MTU32. The active mode is reset automatically to the original one when a tape mark block is detected on a magnetic tape, and at the same time a skip file action end signal is sent to the MTC31. The MTC31 transfers an end signal to the device 30 to complete a skip file instruction. Thus the efficiency is improved for an information processing system, and the alteration of a user program can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention provides a method for quickly searching tape mark blocks (blocks of marks written in a certain code to distinguish files) in a magnetic tape subsystem. This paper relates to a magnetic tape control system that allows for

(b) Prior Art and Problems A magnetic tape subsystem with multiple output/write processing speeds is capable of handling read commands, 1. Cases involving data transfer such as insert instructions, and space block instructions.

If the magnetic tape operation is not continuous because the command is interrupted in one block, such as a pack space command, the magnetic tape subsystem is set to a consecutive failure mode that matches the capabilities of the information processing system in which it is used. We must carry out the Kinuti Edict.

However, in the case of a skip file instruction, which is an instruction that generally skips a file that consists of many blocks and searches for the next tape mark block,
Even if it does not involve data transfer and operates at high speed, it does not necessarily match the capabilities of the information processing system.

The processing speed when executing a skip file command in a magnetic tape device of a conventional magnetic tape subsystem having multiple read/write processing speeds is the processing speed set by the host device up to that time. . Therefore, set it to a low processing speed! ] For positive results, the processing time will be longer because the running speed of the tape is slow. As described above, the skip file command has no effect on the information processing system even if it is processed at high speed, so it is possible to execute the skip file operation at high speed. However, in order to make the skip file operate at high speed, the magnetic tape subsystem must be set to the desired processing mode from the host device. Therefore, it is necessary to set the processing speed again from the upper level equipment.This reduces the efficiency of the entire system because it becomes an il for the medium heat processing equipment of the information processing system, and the user program There are disadvantages that require all operating system changes.

(e) Object of the Invention In order to eliminate the above drawbacks, it is an object of the present invention to provide a magnetic tape control system that automatically operates in high-speed mode during skip file operations without the intervention of a host device d. .

(d) Arrangements of the Invention Arrangements of the invention have multiple read/containment processing speeds;
In a magnetic tape subsystem that performs data read/write operations by selecting a processing speed based on a command from a host device, when a skip file command is issued, the processing speed of the magnetic tape device is recorded. 1: After i, LL, set the processing speed to high-speed mode and execute a skip file operation, and after completing the skip file operation, execute the skip file operation by changing the processing speed of the magnetic tape device according to the stored processing speed. Did you try to restore the previous processing speed? , is.

(e) Embodiment of the Invention FIG. 1 is a block diagram of a circuit showing an embodiment of the invention. Various commands are applied from a host device to a terminal 16 of a magnetic tape controller (MTC), enter a command determination circuit 2, and the contents of the commands are determined. At the same time, the command start command I is applied to the VC terminal 17 and enters the command control circuit 1, so that the command discrimination circuit 2 and the MTU drive control circuit 9 are driven. The MTU drive control circuit 9 sends the rotation direction of the capstan motor 3 and a drive signal to the drive circuit 12 of the magnetic tape unit (MTU) according to the contents of the command from the command discrimination circuit 2. If the command from the higher-level device i is in high-speed mode, the command discrimination circuit 2 sets the terminal 19 to ul" and the circuit 3t also outputs the terminal 19.
If the skilag file is required, set the terminal 20 to ul'' and set the R circuit 3 in the same way.In addition, in the case of low speed mode, select the OR circuit 4 to the concave sphere.The command discrimination circuit 2 is a timing circuit. 8, and in the case of 13% speed mode and skip file instruction, inputs ul'' to AND circuit 5, and since OR circuit 3 is set, ANi) sets circuit 5, and sets Noritsubu flop 11 of MTU. set. Therefore, the flip-flop 11 is connected to the platform drive circuit 12' (
il - run at high speed. Also, the timing circuit 8 is located at J:
! ! Although the speed storage circuit 7 is notified that the processing speed is high, the notification is ignored because the Noritsubu flop 11 has been delayed. When the instruction discrimination circuit 2 contains a low-speed mode instruction (JR circuit 4 is set, the timing circuit 8 is driven, and "l" is sent to the AND circuit 6,
As described above, since the OR circuit 4 is set, the AND circuit 6 is set) and the flip-flop 11 of the MTU is set. When the flip-flop 11 is set to 1, the drive circuit 12 operates at low speed. The timing circuit 8 also notifies the processing speed storage circuit 7 that the processing speed is low, and the processing speed storage circuit 7
Since the count is set, the trace 'J, ll memorizes that the processing speed is low, and the OR circuit 4f: selects.

When a skip file instruction is entered from the higher-level device into the instruction discrimination circuit NT2 while the IVITU is processing in the low-speed mode, the 90-flip ``flop'' 11 in the front 6 is set, and the drive circuit 12 operates in the high-speed mode. MTU head 1
5 takes all 0 of the tape mark blocks recorded on the Shuki Teig, and then reds the target, exit/le 1, and circuit 14.
It is sent to the modulation/demodulation circuit 10 of VITc.

The modulation circuit 10 notifies the instruction control circuit 1 of the detection of the chive mark block, and the instruction control circuit 1 sends a report of the completion of the skip-no-aisle operation to the host device Q' (=skip no aisle operation completion report) from the terminal l8. 10&yo simultaneous ζ'C Timing circuit 8 uses Argmark Bronok Hagiyama, and timing circuit 8 uses A I"J D circuit 6 with t1'F and Jδ
Processing speed record 1. The AND circuit 6 is output together with the OR circuit 4 set by the circuit 7, and the Norilag flop 11 is reset. uL returns to low-speed mode to match the processing speed of parents. At this time, the processing luck Nt memory circuit 7 is reset by -1.

FIG. 2 is a block diagram illustrating another embodiment of the invention. The host device i, 30 gives a skip file command to fvl 'i' C31. #i'l'U31&Y When the command is received, the skinozophy V instruction number 1d is sent to the MTU32. 1 ν 1 TU 32 The processing of the compound sword,
If the speed currently being processed is not the maximum speed, the speed is set to 4th speed [h self 1. Low, automatically ignite the Sukinobu file movement 1 in the Itsukushima operation mode with MTU32 width, and use the tape mark block on the magnetic tape to automatically return to the original operation shade. , the skip file operation photon signal is sent to the MTC 31, the MTC 31 transfers the completion signal to the host device 30, and the skip file alloying is completed.

(f) As described in detail, the present invention improves the efficiency of an information processing system since it is possible to process skip file commands that take a relatively long processing time in a high-speed mode without intervention from a host device. is possible, and can also be used with user programs and O8
There is no need to change the , and the effect is great.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a circuit showing one embodiment of the invention, and FIG. 2 is a diagram illustrating another embodiment of the invention. 1 is a command control circuit, 2 is a command discrimination circuit, 7 is a processing speed storage circuit, 8 is a timing circuit, 9 is an MTU drive control circuit, 10 is a modulation/demodulation circuit, 12 is a drive circuit, 13 is a capstan motor, and 14 is a gun output/write circuit, 15 a head, 30 a host device, 31 a magnetic tape control device, 3
2 is a magnetic tape device.

Claims (1)

[Claims] In a magnetic tape subsystem that has multiple read/write processing speeds and performs data read/write operations by selecting the processing speed based on instructions from a host device, a skip file command is given. At the time, the processing speed of the magnetic tape device is memorized, the processing speed is set to high speed mode θ, and a skip file operation is executed, and after the creation of the skip file M is completed, the stored processing speed is used. υ A magnetic tape control method characterized by returning the processing speed of a magnetic tape device to the processing speed of skip file operation central deletion.