A computer system refers to a computer that tracks information in various forms as input and, through logical and mathematical operations, transforms the data into a suitable form either for processing or use. A computer system processes data to carry out this function, the computer system should be able to communicate with its five components (i.e. input, output, memory, arithmetic) logic and control, within and outside its environment. The data which is to be processed has to go as an input to the system and the result produced after processing the data should be given out as an output by the system in the desired format. To do such job by the computer system, it needs some media to communicate with its outside environment and within itself.
(A) Computer Media
The computer media is that which makes it possible for man to place the data into the computer system and receive information out of it. In the subsequent sections, we are going to describe different types of computer media.
1. Magnetic Tape
Magnetic Tape is the most commonly used sequential access secondary storage medium. It is available in the form of of Cassettes, Reel and Cartridges. Among these three, Reels are the most popular. Reels that could be used with Mini computers and Main frames were 0.5 inch wide and 2400 feet in length. One reel of the tape can store about 50 books of our book size. Magnetic tape is a plastic ribbon coated on one side with an iron oxide material that can be magnetized. Data are recorded in the magnetic tape in the form of small magnetized digits, letters and other characters. Similar to the tape used in our tape recorder, magnetic tape can be erased and reused again and again.
Advantages of Magnetic tapes :
1.Magnetic tapes can be erased and reused.
2.They are economical as far as cost per unit data item storage is concerned.
3.The data density (number of bits stored per inch ) is high.
4.They have fast data transfer rate (the speed at which data can be transferred from the input medium to the CPU).
Disadvantage of Magnetic tapes :
1. As the data in the magnetic tape is accessed sequentially, it is slow to access selected data.
2. Magnetic tapes can be adversely affected by dust, heat and humidity.
3. Contents of magnetic tapes can not be read directly by humans.
Magnetic disks
Magnetic disks are the most popular direct access I/O (i.e. Input/ Output) and online storage medium. Magnetic disks used as storage medium are commonly available in the following forms :
1. Floppy disks
2. Hard disks
(A) Computer Media
The computer media is that which makes it possible for man to place the data into the computer system and receive information out of it. In the subsequent sections, we are going to describe different types of computer media.
1. Magnetic Tape
Magnetic Tape is the most commonly used sequential access secondary storage medium. It is available in the form of of Cassettes, Reel and Cartridges. Among these three, Reels are the most popular. Reels that could be used with Mini computers and Main frames were 0.5 inch wide and 2400 feet in length. One reel of the tape can store about 50 books of our book size. Magnetic tape is a plastic ribbon coated on one side with an iron oxide material that can be magnetized. Data are recorded in the magnetic tape in the form of small magnetized digits, letters and other characters. Similar to the tape used in our tape recorder, magnetic tape can be erased and reused again and again.
Advantages of Magnetic tapes :
1.Magnetic tapes can be erased and reused.
2.They are economical as far as cost per unit data item storage is concerned.
3.The data density (number of bits stored per inch ) is high.
4.They have fast data transfer rate (the speed at which data can be transferred from the input medium to the CPU).
Disadvantage of Magnetic tapes :
1. As the data in the magnetic tape is accessed sequentially, it is slow to access selected data.
2. Magnetic tapes can be adversely affected by dust, heat and humidity.
3. Contents of magnetic tapes can not be read directly by humans.
Magnetic disks
Magnetic disks are the most popular direct access I/O (i.e. Input/ Output) and online storage medium. Magnetic disks used as storage medium are commonly available in the following forms :
1. Floppy disks
2. Hard disks
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