Function of the system unit components

The function of the system unit components and how they communicate


A computer must have four types of basic forms.
· System Unit
· Storage Devices
· Input Devices
· Output Devices


System Unit:

The main body of a computer, consisting of a plastic or metal enclosure, the motherboard, and (typically) internal disk drives, or power supply, cooling fans, and whatever circuit boards plugged into the motherboard, such as a video card and sound card.

Central processing unit:

The Central Processing Unit (CPU) performs the actual processing of data. The data it processes is obtained via the system bus, from the main memory. The results from the CPU are then sent back to main memory via the system bus. The CPU also controls and co-ordinates the operation of the other major components. CPU’s use in their operation: Fetch, decode, execute, and write back. The speed of the CPU is measured in Gigahertz (billions of cycles per second).

Motherboard:

The motherboard is the main circuit board of a microcomputer. It is also known as the main board or system board. It contains and controls the components that are responsible for processing data. A motherboard provides the electrical connections by which the other components of the system communicate. All key internal and external components of the computer plugs into the Motherboard, such as the CPU, RAM, Hard Drive, real time clock, etc. The speed at which information travels across the Motherboard is referred to as the BUS speed.

BIOS:

The BIOS is built-in software that determines what a computer can do without accessing any programs from a disk. On PCs, the BIOS contains all the code required to control the keyboard, display screen, disk drives, serial communications, and a number of other miscellaneous functions.


Storage Devices:

Random Access Memory:

Random access memory (usually known as RAM) is a hardware inside your computer that stores information while you work. RAM is one of the things that make your computer run faster. RAM is not permanent storage of data. Once you turned your computer off, all data in RAM will be lost. RAM is available in different types, sizes, and speeds.

Read Only Memory:

Read Only Memory (also known as ROM) contains startup instructions for each time the computer is turned on. ROM is permanent and remains when even the computer is turned off. This device is used for permanent storage of information. Data can be read many times but can’t be changed, delete or written over.

Integrated Drive Electronics (IDE):

An IDE interface is a standard way for a storage device to connect to a computer. Floppy drive, hard drive and the CD-ROM drive they all devices connect to the computer through an Integrated Drive Electronics (IDE) interface.


Input Devices:

Keyboard:

An input device made up of individual keys representing individual letter, numbers, and symbols. You can use it to type in all your data or information. You can also use your keyboard to perform many of the same tasks you can perform with a mouse.

Mouse:

(A hand-operated electronic device that controls the coordinates of a cursor on your computer screen as you move it around on a pad; on the bottom of the device is a ball that rolls on the surface of the pad) "A mouse takes much more room than a trackball".

Scanner:

An electronic device that uses light-sensing equipment to scan paper images such as text, photos, and illustrations and translate the images into signals that the computer can then store, modify, or distribute.

Microphone:

A device used to convert sound into electrical signals, which can then be amplified or transmit for broadcasting. You can also use it for recording sounds such as music or voice.


Output Devices:

Printer:

A device for printing results from your computer on paper or other "hard" media. While there are many kinds of printers, most these days fall into two groups. Inkjet printers use a technique to "spray" the ink onto your paper.

Speakers:

A loudspeaker, speaker, or speaker system is an electromechanical device which plays sound. They may be built into the system unit or can be connected with cables. Speakers allow you to listen to music and hear sound effects from your computer.

Monitor:

A monitor displays information in visual form, using text and graphics. The portion of the monitor that displays the information is called the screen. Like a television screen, a computer screen can show still or moving pictures. Monitor attaches with system through a cable and whatever you will do in a computer will show you on the monitor screen.


Other Components:

Modem:

Equipment that converts digital signals into analogue signals for purpose of transmission over a telephone line. Signal is then converted back to digital form so that it can be processed by a receiving computer. Modems are typically used to link computers via telephone lines.

Hard Disk Drive:

Your computer's hard disk drive stores information on a hard disk, a rigid platter or stack of platters with a magnetic surface because hard disks can hold massive amounts of information. They usually serve as your computer's storage which holds almost all of your programs and files. The hard disk drive is normally located inside the system unit.

Video Card:

The video card is a board that plugs into the PC motherboard to give it display capabilities. New video cards come with their own RAM and processor to help speed up the graphics display. Many computers come with video chips built in. That makes a separate video card unnecessary, unless the computer is going to be used for high-end multimedia work or to play video games.

Conclusion:

Computer components are connected to each other via thin connections known as BUS on the motherboard. Once you have attached all the components/devices with each other through BUS, your system will work successfully.