Windows,

System Unit of Computer

System Unit of Computer this is the technical term referring to the box or casing that

accommodates your computer hardware, is the system unit

includes the motherboard, microprocessor and main memory,

buses and ports. It does not include the keyboard or monitor,

or any other peripheral device.

A system unit may be sometimes called a main or the box unit.

Note: Input and output devices other than basic input and

output devices are also called the peripheral devices.

Types of Computer Processors

The older Intel versions include the 386, 486. Now Pentium line is in the market.

Pentium line includes P-I to P-IV. Multicore processors include Pentium dual core

or Core 2 duo or Core X2 and quad core (four processors in one).

A dua l core processor is a CPU with two separate cores on the same die however Each

CPU has its own cache. It is the equivalent of getting two microprocessors in one.

Thus, dual core chip has two independent computer processors that can work

together for increasing the total computer performance

Tasks performed by Processor:

1. It processes data

2. It controls the overall data movement inside the computer

Features: The main feature of a microprocessor is its speed and the speed is measured

in hertz (Hz). It is the internal processor speed in which computer instructions are

performed.

Note: There is difference between "dual core" and "core duo." These are the

same, except that first one is Intel's own name for their dual core

technology. So core 2 duo is just a brand name for the dual core technology

Components of  Microprocessor: A microprocessor consists of a memory, control

unit (CU) and arithmetic logic unit (ALU).

Control unit (CU): The most important activity of CPU is to direct the rest of computer

system parts, that is what to do and how to do . This is carried out by control unit.

It directs the entire computer devices to communicate with each other.

Tasks performed by Control unit:

It gets instructions from memory

It controls the instructions to be performed by ALU

It It sends the information and data to the memory ) 

Arithmetic logic unit (ALU) : An arithmetic logic unit (ALU) is the part of a computer

(microprocessor) that carries out arithmetic and logic operations. In some processors,

the ALU is divided into two units, an arithmetic unit (AU) and a logic unit (LU). Some

processors contain more than one AU_ for the example, one is for fixed-point operations and

another for floating-point operations.

performed by Arithmetic logic unit: G It performs addition, subtraction, multiplication, division, etc.

• It also compares two values, e.g. 6>5