Computer Hardwares

What are Computer Hardwares?

Hardware (computer) components, equipments involved in the function of a computer. Computer hardware consists of the components that can be physically handled. The function of these components is typically divided into three main categories: input, output, and storage.

Components in these categories connect to microprocessors, specifically, the computer's central processing unit (CPU), the electronic circuitry that provides the computational ability and control of the computer, via wires or circuitry called a bus.

Software, on the other hand, is the set of instructions a computer uses to manipulate data, such as a word-processing program or a video game. These programs are usually stored and transferred via the computer's hardware to and from the CPU.

Software also governs how the hardware is utilized; for example, how information is retrieved from a storage device. The interaction between the input and output hardware is controlled by software called the Basic Input Output System software (BIOS).

Although microprocessors are still technically considered to be hardware, portions of their function are also associated with computer software. Since microprocessors have both hardware and software aspects they are therefore often referred to as firmware.

There!

That's it. That's basic components of computer hardwares. You can review deeper dreakdowns for each categories by clicking on categories and subcategories on your right hand side. We subdivided each categories as follows.

• Input Devices
• Output Devices
• Storage Devices
• Hardware Connections

Computer Input Devices

Input devices consists of external devices - that is, devices outside of the computer's CPU - that provide information and instructions to the computer.

Light pen

A light pen is a stylus with a light sensitive tip that is used to draw directly on a computer's video screen or to select information on the screen by pressing a clip in the light pen or by pressing the light pen against the surface of the screen. The pen contains light sensors that identify which portion of the screen it is passed over.

Mouse

A mouse is a pointing device designed to be gripped by one hand. It has a detection device (usually a ball) on the bottom that enables the user to control the motion of an on-screen pointer, or cursor, by moving the mouse on a flat surface. As the device moves across the surface, the cursor moves across the screen. To select items or choose commands on the screen, the user presses a button on the mouse.

Joystick

A joystick is a pointing device composed of a lever that moves in multiple directions to navigate a cursor or other graphical object on a computer screen.

Keyboard

A keyboard is a typewriter-like device that allows the user to type in text and commands to the computer. Some keyboards have special function keys or integrated pointing devices, such as a trackball or touch-sensitive regions that let the user's finger motions move an on-screen cursor.

Optical Scanner

An optical scanner uses light-sensing equipment to convert images such as a picture or text into electronic signals that can be manipulated by a computer. For example, a photograph can be scanned into a computer and then included in a text document created on that computer.

The two most common scanner types are the flatbed scanner, which is similar to an office photocopier, and the handheld scanner, which is passed manually across the image to be processed.

Microphone

A microphone is a device for converting sound into signals that can then be stored, manipulated, and played back by the computer.

voice recognition

A voice recognition module is a device that converts spoken words into information that the computer can recognize and process.

Modem

A modem, which stands for modulator-demodulator, is a device that connects a computer to a telephone line or cable television network and allows information to be transmitted to or received from another computer. Each computer that sends or receives information must be connected to a modem. The digital signal sent from one computer is converted by the modem into an analog signal, which is then transmitted by telephone lines or television cables to the receiving modem, which converts the signal back into a digital signal that the receiving computer can understand.

There are few different types of Modems including...

Analog: 56K (52K top speed) using telephone line.

DSL/ADSL: Top speed can reach as high as 5 Mb in residential using telephone line.

Cable: Top speed about 8 Mb using Cable.

FiberOptic: Can reach 30Mbps depend on your available provider.

Modem is input device as well as output device. So, we will place detaied articles about modems under "Networking" category.

Output Device

Output hardware consists of external devices that transfer information from the computer's CPU to the computer user. A video display, or screen, converts information generated by the computer into visual information.

Display

Displays commonly take one of two forms: a video screen with a cathode ray tube (CRT) or a video screen with a liquid crystal display (LCD).

CRT

A CRT-based screen, or monitor, looks similar to a television set. Information from the CPU is displayed using a beam of electrons that scans a phosphorescent surface that emits light and creates images.

Flat Panel or LCD

An LCD-based screen displays visual information on a flatter and smaller screen than a CRT-based video monitor. LCDs are frequently used in laptop computers.

Printers

Printers take text and image from a computer and print them on paper. Dot-matrix printers use tiny wires to impact upon an inked ribbon to form characters. Laser printers employ beams of light to draw images on a drum that then picks up fine black particles called toner. The toner is fused to a page to produce an image. Inkjet printers fire droplets of ink onto a page to form characters and pictures.

Speakers

Ahh... Gamers can not ignore this category. However, we'll talk about that in later time.

Storage Devices

Storage hardware provides permanent storage of information and programs for retrieval by the computer. The two main types of storage devices are disk drives and memory.

There are several types of disk drives: hard, floppy, magneto-optical, and compact.

Hard disk drive

Hard disk drives store information in magnetic particles embedded in a disk. Usually a permanent part of the computer, hard disk drives can store large amounts of information and retrieve that information very quickly.

Floppy disk drive

Floppy disk drives also store information in magnetic particles embedded in removable disks that may be floppy or rigid. Floppy disks store less information than a hard disk drive and retrieve the information at a much slower rate.

Magneto-optical disc drive

Magneto-optical disc drives store information on removable discs that are sensitive to both laser light and magnetic fields. They can typically store as much information as hard disks, but they have slightly slower retrieval speeds.

Compact disc drive

Compact disc drives store information on pits burned into the surface of a disc of reflective material. CD-ROMs can store about as much information as a hard drive but have a slower rate of information retrieval. A digital video disc (DVD) looks and works like a CD-ROM but can store more than 7 times as much information.

Memory

Memory refers to the computer chips that store information for quick retrieval by the CPU. Random access memory RAM is used to store the information and instructions that operate the computer's programs.

Typically, programs are transferred from storage on a disk drive to RAM. RAM is also known as volatile memory because the information within the computer chips is lost when power to the computer is turned off.

Read-only memory (ROM) contains critical information and software that must be permanently available for computer operation, such as the operating system that directs the computer's actions from start up to shut down. ROM is called nonvolatile memory because the memory chips do not lose their information when power to the computer is turned off.

Some devices serve more than one purpose. For example, floppy disks may also be used as input devices if they contain information to be used and processed by the computer user. In addition, they can be used as output devices if the user wants to store the results of computations on them.

Memory - RAM

RAM is Random Access Memory. It is the part of the computer that processes information. When a program is started it is loaded into RAM to be run.

Inside your computer is one or more slots (usually black) that contain memory chips. Most computers ship with only one filled. To add RAM to the computer you need to find out what kind of RAM (Random Access Memory) your computer takes. The manual that came with your computer's motherboard should have details on what kind of RAM you will need, how much RAM each slot can take and how many slots your computer has. When you receive the upgrade chips they simply snap into the slots on the motherboard.

In Windows, click your START button (bottom left) and click Settings, then Control Panel (In XP, click START then Control Panel). Then click the System icon and look at the info listed on the General tab. The amount of RAM in your system will be listed there in megabytes (MB).

Once the RAM is installed your Windows 95/98/ME/2000/NT/XP system will automatically detect the new memory and start using it.

Adding RAM is the easiest, most cost effective way to boost your computer’s performance.

There are many types of RAM: EDO, FPM, SDRAM SODIMM, RAMBUS and more. Your manual or manufacturer should be able to explain what kind of RAM you have and need. If you have a brand name computer a quick way to figure out what RAM you need is to see Crucial's Memory Advisor. Pick your computer brand from the list below and then the model and model number. It will report what type of RAM you need to buy and how much it will cost.

Every computer has a different maximum amount of RAM you can install. Each motherboard (the big circuit board in your computer) has different a maximum. The are a couple of ways you can figure out how much RAM your motherboard can hold. If you still have a manual that came with your computer, there should be information found in there that shows how many RAM slots are on your motherboard, how much memory each slot can take and what the maximum amout of RAM your system can use.

Modem

A modem is a device that converts digital signals from a computer's serial port to the analog signals required for transmission over traditional telephone lines, and vice versa. Modem stands for modulator/demodulator.

Conversion is necessary because telephone lines were initially designed to handle the analog nature of the human voice, not data. Modems provide remote access to machines in the field to eliminate unnecessary site visits and provide fast access to information in the machine.

The speed of a modem is measured by the rate at which it sends and receives data. This is expressed as bits per second (bps), thousands of bits per second (Kbps) and/or Megabits per second (Mbps). The term baud is approximately equivalent to bps.

Some modems have a V number on them to express their speed and features. V32bis modems run up to 14.4 kbps, V34 modems up to 28.8 kbps, and V34plus modems up to 33.6 kbps. The most recently-adopted standard is the V.90 standard for 56 kbps modems.

Telephone lines are the cheapest way of connecting to the Net, allowing connection speeds up to about 56 kbps. No matter what your modem speed is, actual connection speed may be less than the modem's rated speed depending on the quality of the line.

Connection speed may also vary from connection to connection. You can run your Internet connection from your existing telephone line but if you do, be aware that when you are online you cannot receive or make telephone calls using that line.

You might want to get a separate line for the Internet connection or, if you have a fax line already and you don't use it a lot, you can probably utilise this connection. If you want faster connections to allow you to spend less time online, or to make your time online more interesting and more immediately interactive, you can get connected through ISDN, DSL lines or cables.