What is Magnetic Memory?

MAGNETIC MEMORY

Magnetic memory is also called secondary storage. It is used to store computer instructions and data permanently. The instructions and data stored on the magnetic memory are not lost when the computer is on the magnetic memory. Magnetic memory consists of a magnetic medium on which information is stored. Most common medium used for magnetic memory is disk. This is why magnetic memory is also called Disk Memory. There are two most common type of magnetic memories. These are floppy disks and hard disks. The magnetic memory has large capacity as compared to RAM. The reading and writing of data on magnetic is however much slower than in the RAM. Magnetic memory is used to store instructions and data permanently. When instructions are to be executed these are loaded from the magnetic memory into the RAM.

What is a computer Bus? Explain important types of buses.

COMPUTER BUSES

The electrical paths through which data is transferred from one component to another within the computer system are called computer buses. These buses connect different devices with the CPU. A bus consists of a set parallel electrical paths, usually copper tracings on the surface of the motherboard. The amount of data that a bus can carry at one time is called bus width. Bus width is measured in terms of how many bits can be carried at one time. Nowadays Intel Pentium microprocessors have 64-bit data buses. The greater the width of the computer bus, the more data it can transfer. Thus a larger bus width in a computer means a faster and more powerful computer. A computer system has several types of buses. Important buses are-discussed below:

DATA BUS

The data bus connects different parts of the computer. It is used to transfer data from one device to another.

ADDRESS BUS

The bus that is used to locate a storage position in the computer memory is called address bus. It used to locate the address of data in memory. It is also used locate the memory address of instructions to be executed.

CONTROL BUS

It is used to transfer control from one instruction to another during program execution. It also transfer control signals to different devices.

EXPANSION BUS

The bus that carries data to and from expansion on the motherboard is called expansion bus. Additional card for example, network cards, modems, sound cards are added to the expansion slots. The expansion buses connect these cards to the computer system.