Computer Components

by Jayaram V

Most of us by now should be familiar with the basic aspects of a computer. In computer terminology, computer hardware refers to the physical parts of the computer such as keyboard, monitor, motherboard, hard drive etc. Computer software refers to the operating system, data files and application or programming software which provide instructions to the hardware to perform, essentially, four basic functions: input, processing, output and storage. Here we focus basically on the computer hardware and understand how a computer is structured physically.

Computer hardware basically consists of  input (keyboard, mouse, etc.) and output devices (monitor, printer, etc.), and the Central Processing Unit , which is commonly known as the CPU. Data received by the Input devices is sent in binary form to the CPU where it is processed and either stored in a storage device such as hard disk or sent to the output devices for display or further processing.

Input Output Devices and Ports

The most popular input and out devices are the keyboard and the monitor. These communicate with the CPU through cables or wireless and connection points called ports. If you have a computer you can see these ports located usually on the backside of your computer case. Now a days, however, it is not uncommon to see them on the front side of a computer also. Some of the well known ports attached to a computer go by such names as mouse port, keyboard port, usb ports, parallel port, serial port, video port, network port etc. As you can see from these names, the ports connect not only input devices but also output devices to the CPU.

Key Board: What we see now a days are the enhance keyboards that come in many different shapes, colors and sizes and usually hold about 102 keys. A keyboard can be attached through a keyboard port or a usb port to the CPU usually by means of a cable but necessarily as we have now a days wireless keyboards that can be managed remotely.

Mouse: A mouse is a pointing device whose invention and entry into the computer world revolutionized the way we interact with the computer systems. A traditional mouse contains a rotating ball at the base and some buttons at the top. 

The most important output devices are the monitor and the printer. As said earlier these are connected to the CPU though through cables or wireless at connecting points on the CPU called ports. Both the monitor and the printers come in different shapes, sizes and types. The output devices usually require an independent electric supply. 

The Inside World of a Computer Case

If you look inside a computer case (not the empty one I mean) you will see many parts and a confusing mass of data cables and power cords. Especially, you should be able to see some of the most important and widely known parts such as the following:

1. System board or the mother board consisting of the CPU and the accompanying microchip/s or chipset, a coprocessor (in case of old computers), system clock, ROM BIOS, Random Access Memory (RAM), cache memory (optional), flash BIOS, CMOS configuration chip with its battery, power supply connections, system bus with  expansion slots, jumpers and dip switches and ports. Of these some (CPU, ROM, BIOS etc.) are replaceable or upgradeable while other are not. The system board is the most complicated part of a computer hardware where most of the activity takes place. It is very much like the brain with which all the devices in the computer need to communicate some how. A system board as the name implies manages the performance of all other devices that are connected to it either internally or externally.

2. Depending upon the configuration storage devices such as one or two floppy drives, one or more hard drives, one ore more CD-ROM/DVD-ROMs,  Zip drive and so on.

3. A power supply that receives electricity from outside and then supplies it to all the devices inside the case. It usually contains a cooling fan on the back to protect itself and other computer hardware from over heating.

4. Circuit boards which enable the CPU to communicate with other devices both with in and outside the computer case. The circuit boards contain microchips or integrated circuits, which can be either CMOS (complimentary metal oxide semiconductor) chips or TTL (transistor-transistor logic) chips. These chips differ in their functionality and also the way they use electricity, manage heat and hold the data. But we won't go into these minor details. 

5. Storage devices. The storage devices inside a CPU are either primary storage devices or secondary storage devices. The primary storage devices help the CPU to process data or instructions by holding information temporarily. They are therefore temporary storage devices and the memory they hold is called volatile memory. 

Primary Storage Devices: The most common type of primary storage devices are the memory chips which can hold either random access memory (RAM) or cache memory or both. If cache memory is stored on the system board it is called COAST (cache on a stick).

Secondary Storage Devices: In contrast to primary storage devices, the data that is stored here is more permanent. that is they can hold the data even when the computer has been switched off and will remain so until some external agent or device physically removes the data. Anther big difference is while the the CPU can process the data residing in the primary storage devices directly, it cannot do so with the data residing in the secondary storage devices. For that the data need to be moved to the primary storage device.

This in brief is the basic configuration of computer hardware. If you are looking for new computers, computer accessories or refurbished computers use this link.