THE ESSENTIAL COMPONENTS OF A BASIC COMPUTER SYSTEM

HARDWARES

Central Processing Unit(CPU)

A Central Processing Unit (CPU), or processor, is a description of a class of logic machines that can execute computer programmes. The CPU is the brains of the computer where most calculations take place. In terms of computing power, the CPU is the most important element of a computer system. Many of today's PCs use either an Intel Pentium 4 or its cheaper and slower cousin, the Celeron. Another popular processor is the AMD Athlon 64. The speed of the processor is measured in either megahertz (MHz) or gigahertz (GHz). The faster the speed of the processor, the faster the PC will perform, and surely the higher the price of the computer will be.

On large machines, CPUs require one or more printed circuit boards. On personal computers and small workstations, the CPU is housed in a single chip called a microprocessor. The CPU itself is an internal component of the computer. Modern CPUs are small and square and contain multiple metallic connectors or pins on the underside. The CPU is inserted directly into a CPU socket, pin side down, on the motherboard. Each motherboard will support only a specific type or range of CPU. Modern CPUs also have an attached heat sink and small fan that go directly on top of the CPU to help dissipate heat.

Two typical components of a CPU are the following:

• The arithmetic logical unit (ALU), which performs arithmetic and logical operations.
• The control unit (CU), which extracts instructions from memory and decodes and executes them, calling on the ALU when necessary.

Integrated Circuit

An integrated circuit (IC), sometimes called a chip or microchip, is a semiconductor wafer on which thousands or millions of tiny resistors, capacitors, and transistors are fabricated. The first integrated circuit was developed in the 1950s by Jack Kilby of Texas Instruments and Robert Noyce of Fairchild Semiconductor. An IC can function as an amplifier, oscillator, timer, counter, computer memory, or microprocessor. A particular IC is categorized as either linear (analogue) or digital, depending on its intended application.

• Linear ICs are used as audio-frequency (AF) and radio-frequency (RF) amplifiers. The operational amplifier (op amp) is a common device in these applications.
• Digital ICs are used in computers, computer networks, modems, and frequency counters. The fundamental building blocks of digital ICs are logic gates, which work with binary data, that is, signals that have only two different states, called low (logic 0) and high (logic 1).

Integrated circuits can also be classified by the number of transistors and other electronic components they contain:

• SSI (small-scale integration): Up to 100 electronic components per chip
• MSI (medium-scale integration): From 100 to 3,000 electronic components per chip
• LSI (large-scale integration): From 3,000 to 100,000 electronic components per chip
• LCSI (very large-scale integration): From 100,000 to 1,000,000 electronic components per chip
• ULSI (ultra large-scale integration): More than 1 million electronic components per chip