Internal System Unit Components Computer Science Essay

Published: Last Edited:

This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.

The processor or the CPU Central Processing Unit is the brain of the computer. The processor carries out the instructions in a program and controls all the work in the computer. Each of the separate components of CPU on its own is relatively simple. The key components of a CPU are the arithmetic logic unit (ALU), control unit and registers.

Control unit control the flow of the information through the processor. This component receives, decodes, stores the result and manages the implementation of the data that flows through the CPU. It decides what actions it has to take and ensure that the data is sent to the appropriate components in the computer.

Arithmetic Logic Unit is the part of CPU where all calculations are made. ALU performs the mathematical functions of addition, subtraction, multiplications, division and the logic operations. These include timing, number system and instructions.

Registers is basically controlled by control unit and a necessary part of the CPU. Registers are temporary memory where it used to keep the data and other information while the program is running. Another type of registry is to accumulate, which is responsible for storing the next value that will be processed by the CPU.

Processors also communicate in different ways. Like AMD and Intel; AMD is using the chipset hyper transport and Intel is using the front side bus to communicate.


Motherboard allows all the computer parts to communicate to each other and it also the primary hardware component inside a computer system.

The main components of motherboard are:

CPU Chip: The CPU is Central Processing Unit which controls all the calculations and decisions inside the PC. The CPU have all the control over the work is running on PC.

RAM: Random Access Memory provides the working area for the CPU. Its keep all the temporary memory of the running programs and stores the data or information's as temporary.

Floppy Controller: Is the hardware responsible for interfacing the floppy drives on your computer. It manages the flow of information from floppy to system processor.

IDE Controller: Integrated Drive Electronics is connection for you hard drive or CD/DVD drive. It has the responsible for controlling the hard drive.

PCI Slot: PCI slot can be used for components such as Ethernet cards, sound cards and modems. The PCI bus is used to connect I/O devices to the main logic of the computer.

CMOS Battery: This is motherboard battery. This battery is used to allow the CMOS to keep its settings.

AGP Slot: Stand for Advance Graphic Port and this is to connect the graphics card in to the motherboard.

Power Supply Plug In: This is the component that supplies power to the other components of the computer. It communicates with other parts of the computer and supplies the power to it.


Basic Input Output System is a chip located on all the computer motherboard which contains instructions and setups for how the system should boot and to make sure that all the other chips, hard drives, memory and CPU functioning together. The BIOS chips are a ROM (Read Only Memory) that means that you can access the information and read it by the user, but not modified it.

Some main functions of BIOS are:

It's ensures that the hardware on computer is properly functioning before starting the process of loading operating systems.

Allow you to configuration against the configuration data. Hardware settings and other system settings you can use the diagnostic tool and fix the problem.

BIOS also give the computer basic information about how to interact with some critical components.

Power supply

Power supply is the component that supplies power to make the computer and components work. It provides all of the different voltages your computer needs to operate properly. The power supply needs to produce enough wattage to allow the motherboard processor and other component to work properly. There are two different types of power, internal (Alternating current) and external (Direct current).

The power supply also referred as switching power supplies. The power supplies pull the required amount of electricity and convert the AC input current to DC voltages.

The typical voltages supplied are:

3.3 volts

5 volts

12 volts

Fan and heat sink or cooling

It's a physical device to keep the processor cool from the heat. Keeping processor is a major part of PC performance. Without them the components on your computer can get damage or even crash the system. The fan extracts the hot air from the case and keeps the components cooled down all the time. Heat sink is another device which sits over the CPU and keeps the CPU cooled down. The CPU is the one of the most important chip and to make the system more efficient the CPU most work properly. Some components generate a lot of heat and these can affect other chips close to them. Like 3D video cards and graphics cars generates a lots of heat.

Hard drive configuration and controllers (e.g. SATA, IDE, EIDE, Master, Slave)

Hard disk is a computer component where you can save large amount of data and other information that you need on it. You may also be used as a backup device. It is also called as Non-Volatile memory. There are three main hard drive controllers which is SATA, IDE and EIDE

SATA: Serial Advanced Technology Attachment is a mass storage device where you can save your data and information on it. It's the next generation drive interface from the traditional Parallel ATA. The main function of SATA is to send data in serial mode.

IDE: Integrated Drive Electronics have two different types of IDE controller, a primary IDE controller and a secondary IDE controller. It is a standard electronics interface between a computer motherboard and the computer disk. IDE is used to connect different drives to the computer but the main function is to send and receive data to and from the drive. The secondary IDE controller can be used on CD, DVD drivers and floppy drives.

EIDE: Enhanced Integrated Drive Electronics is a standard electronics interface between your computer and storage device. EIDI is an improved version of IDE which provides much faster data rates than the original one and make it easy when you are working with computer hardware. The EIDE is also knows as ATA-2.

There are two IDE controller, primary and secondary controller. You can assign master and slave to the primary and secondary drives to them. This allows one drives controller to tell the other drive when it can transfer the data or from the computer. The slave drive makes a request to the master drive if the information or the data can be sent. It's up to master to decide what action it has to take. If the master drive is not communicating with the computer it allows to send the information otherwise it tells the slave drive to wait.

Communication ports e.g. USB, parallel, serial

A communication port allows you to transmitting the data between a computer and peripheral device. A communication port is also called serial port and uses a transmitter to send data, one bit at time. Most computer has communication port because no extra or other hardware is needed other than a cable to connect.

Internal memory (RAM, ROM, cache)

Specialized card e.g. network, graphics cards


Output devices eg monitor, printer, plotter; (11) input devices eg camera, scanner; (12) cabling eg coaxial, optical, twisted pair;

Backing Storage:

Portable and fixed drives - types eg disks, pen drives, optical media, flash memory cards;