These are the storage media mostly used in Mini and Mainframe computers.
A Magnetic Tape reel is made of a plastic ribbon/ band coated on one side with a magnetic material that enables data & instructions to be recorded/ stored on the tape.
Magnetic Tape – a tape with a magnetic surface on which data can be stored by selective polarization of portions of the surface.
The reels of the Tape are stored in a protective case, which safeguards the recording surface of the reel from environmental destructions, e.g., touch, dust, direct sunlight radiations, etc.
Usually, a plastic ring (the Permit ring) is affixed on the Permit Ring Groove, which is on the case, before the tape is mounted in its deck. The Permit ring is used to protect/ safeguard the contents of the tape.
If the permit ring is affixed, the tape surface can be written to & read from, hence it is possible to alter the contents of the tape. If the permit ring is not affixed onto its groove, the tape surface can be read but cannot be written to; hence the tape user cannot alter the tape contents.
The width of the tape is divided into Tracks, while the length is divided into vertical columns called Frames. Each frame is made up of 7 storage unit areas (bit positions). These frames are used to store individual characters across the tape width.
The recording surface of a tape has 7 or 9 tracks running along its length. Each recording position on a track can be magnetized to represent a ‘1’, while that which is not magnetized represents a 0. Thus for a 9-track tape, each frame contains 9 bits & is used to represent 1 character.
A tape is usually ½ (0.5) inch wide & 2,400-feet long. The characters are recorded across the tracks on the tape.
Kavungya answered the question on
April 2, 2019 at 07:39