JPS59128656A - Method for displaying used quantity of magnetic tape - Google Patents

Abstract

PURPOSE:To display the used quantity of a magnetic tape by storing the measured value of the used quantity of the magnetic tape in a data storing area of a CPU and the magnetic tape itself. CONSTITUTION:The magnetic tape 11 is carried by the revolution of a carrying roller 7 and information is written and read out by a magnetic head 6. A disc 8 is fitted to the roller 7, a hole 8-1 is drilled into the disc 8 and a photoelectric conveter 9 is fitted to a position corresponding to the hole 8-1. The converter 9 outputs one pulse signal every one revolution of the disc 8 and a counter 10 counts up the signal. Therefore, the carried quantity of the tape is determined by the counted value. On the other hand, the CPU executes the processing, stores the executed result in a file and records the used quantity of the tape in the file. In addition, the used quantity is recorded in a label part of the tape at the completion of writing in the tape 11. Consequently, the contents can be displayed at a required time.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a system for displaying the usage amount of magnetic tape used in a magnetic tape device used in a computer system.

('b) Prior Art and Problems A magnetic tape device is known as a device for storing information in an electronic computer system. This magnetic tape device is widely used because it is inexpensive compared to the amount of information stored. Information about the magnetic tape device is stored on the magnetic tape. Various types of information are stored on this magnetic tape, and there are label portions for identifying the information.These label portions are used as information tags and are provided at the beginning and end of the volume. When storing information using this magnetic device, it is not only inconvenient to handle the magnetic tape device because it is difficult to know the length of the magnetic tape that has already been written and therefore the remaining length of the magnetic tape that can be written, but also the magnetic tape is inconvenient. There were drawbacks such as economics.

(C) Object of the Invention In view of the above-mentioned drawbacks of the conventional art, it is an object of the present invention to provide a magnetic tape usage display method that can display the usage length of the magnetic tape.

(1) Structure of the Invention Briefly stated, the present invention provides a magnetic tape device with means for measuring the amount of magnetic tape used, and stores the output of the measuring means in the data storage area of the central processing unit r6 and on the magnetic tape. This is characterized by the fact that the amount of magnetic tape used can be easily obtained.

(e) Embodiments of the Invention Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a block diagram of an embodiment of the magnetic tape usage display system of the present invention, and FIG. 2 is a perspective view of essential parts of the magnetic tape length measuring means of the present invention.

In the figure, l is a central processing unit, 2 is a file, 8 is a writer, 4 is a magnetic tape device, 5 is a printing device, 6 magnetic heads, 7 is a conveyance roller, 8 is a disk, 9 is a photoelectric conversion element,
IO and 11 respectively indicate a karashita and a magnetic tape. Figure 2 shows the main part of the magnetic tape transport amount, and shows the magnetic tape 1
1 passes through a magnetic head 6, is held between conveyance rollers 7, is conveyed by the rotation of the conveyance roller rough, and information is written and read by the magnetic head 6. This transport row"U7
A disk 8 is attached to the disk 8, and a slit-shaped hole 8 is attached to this disk 8.
-1 is drilled, and a photoelectric conversion element 9 is provided at a position corresponding to this hole 8-1. The photoelectric conversion element 9 outputs a signal of l pulses for one rotation of the disk 8. A counter IO receives this signal and performs counting.

Therefore, the amount of tape conveyance is determined by the outer circumference length of the conveyance roller 7 x count value. On the other hand, the central processing unit l interprets the command, executes the process based on the control information of the control block, and stores the execution result in the file Iv2.
/2 is connected to the printing device 5 by the writer 3. In addition to recording the above-mentioned tape conveyance amount, that is, usage amount in this file/I/z, the usage amount is also recorded on the label portion of this tape when writing to the magnetic tape 11 is completed. If necessary, the writer 3 is activated and the usage status is outputted by the printer 5.

(f) Effects of the Invention As explained in detail above, the magnetic tape usage display method of the present invention stores the content in the central processing unit, and also clearly indicates the usage on the magnetic tape so that the content can be displayed when necessary. This provides many advantages when handling magnetic tape devices.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the magnetic tape usage display system of the present invention, and FIG. 2 is a perspective view of essential parts of the magnetic tape length measuring means of the present invention. In the figure, l indicates a central processing unit, 2 indicates a file, 4 indicates a magnetic tape device, and 11 indicates a magnetic tape.

Claims (1)

[Claims] A system for displaying the amount of magnetic tape used in a system consisting of a magnetic tape device and a central processing unit, wherein the magnetic tape device is provided with means for measuring the amount of magnetic tape used, and the output of the measuring device is sent to the central processing unit. A magnetic tape usage display method characterized in that data is stored in a data storage area of a processing device and in the magnetic tape.