What is the fastest accessible storage?

What is the fastest accessible storage?

The fastest access is tape storage. Tape storage is a magnetic surface memory and uses tape as a storage medium. The tape drive is composed of a tape transmission mechanism and a magnetic head, which can drive the tape to move relative to the magnetic head. A magnetic head is used for electromagnetic conversion to sequentially record or read data on a magnetic tape.

Tape memory characteristics

After the magnetic material is magnetized, the operating point is always on the hysteresis loop. As long as the amplitude of the externally applied forward pulse current (ie, the external magnetic field) is large enough, the magnetic induction intensity B will not be equal to zero after the current disappears, but will be in the Br state (positive residual magnetization state). On the contrary, when a negative pulse current is applied, the magnetic induction intensity B will be in the -Br state (negative residual magnetization state). When a magnetic material is magnetized, it forms two stable states of residual magnetism, just like a flip-flop circuit has two stable states. If it is specified that the Br state represents the code 1 and the -Br state represents the code 0, then to make the magnetic material remember 1, a forward pulse current must be added to make the magnetic material forward magnetized; to make the magnetic material remember 0, a negative pulse current must be added Pulse current to reversely magnetize the magnetic material. The place on the magnetic material that exhibits a remanent state forms a magnetized element or storage element, which is the smallest unit for recording a binary information bit.

Storage Principle

Tape memory belongs to magnetic surface memory, and the external memory of the computer is also called magnetic surface storage device. The so-called magnetic surface storage uses certain magnetic materials thinly coated on the surface of metal aluminum or plastic as a magnet to store information.

The tape controller is an interface device that connects the computer and the tape drive. One tape controller can connect to multiple tape drives. It is a control circuit device used by computers to access data on tapes. It can control the tape drive to perform operations such as writing, reading, and advancing and retreating files.

A tape drive is a digital magnetic recording device that uses tape as the recording medium. It consists of a tape transmission mechanism, a servo control circuit, a read-write head, a read-write circuit and related logic control circuits.

Tape is a soft tape-shaped magnetic recording medium. It consists of two parts: a tape base and a magnetic surface layer. The tape base is mostly made of thin film polyester material, and the materials used in the magnetic surface layer are mostly γ-Fe2O3 and CrO2 etc. Tape storage accesses data sequentially. The tapes on which the data is stored can be saved offline and read interchangeably. In addition, it also has the characteristics of large storage capacity, low price, and easy portability. It is one of the important peripheral devices of the computer.

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