Computer System Components: Computer Parts & Functions
Desktop or Laptop?
I typically refer to the computer I use as my laptop. The one my son uses is our desktop, even though it doesn't sit on the desk!
How about we go shopping for a new computer system for you? First we'll have to figure out if a desktop or a laptop is going to be best for you. One thing that I'll use in terminology is the system unit. This is the case that contains all of the components needed for your computer to work. The two constructions available to you are the desktop (or tower) or a laptop.
Laptops are for the user who prefers portability. This unit is common for someone like you - a college student, consumers who travel frequently and business people who find themselves working in places other than their office.
The desktop, or tower, is intended for a user who doesn't need a computer that is portable. They are larger in design and often have more features and computing power.
Now that you know for sure what the differences between the two are, which system seems like it would be best for your situation? Let's talk about the details of how computers we're looking at are put together. Many of the components I'll show you will have more than one choice for you. Your budget is going to be what drives many of the decisions that you make.
Mouse
A mouse is a small device that a computer user pushes across a desk surface in order to point to a place on a display screen and to select one or more actions to take from that position. The mouse first became a widely-used computer tool when Apple Computer made it a standard part of the Apple Macintosh. Today, the mouse is an integral part of the graphical user interface (GUI) of any personal computer. The mouse apparently got its name by being about the same size and color as a toy mouse.
Motherboard
Now, the first thing is the motherboard. It's the basis of your computer. It's the first component installed in the system unit, and it holds all of the circuitry that ties the functions of the computer components together.
You can think of it like your car (which has many computer systems of its own). If you have a frame and tires, you've got a car (or you've got a system unit), but it won't take you very far! Now, add your engine - the motherboard - where all the systems tie in one way or another, and you've got the start of a working vehicle.
History of Computers
The executable instructions composing a program were embodied in the separate units of ENIAC, which were plugged together to form a route through the machine for the flow of computations. These connections had to be redone for each different problem, together with presetting function tables and switches. This "wire-your-own" instruction technique was inconvenient, and only with some license could ENIAC be considered programmable; it was, however, efficient in handling the particular programs for which it had been designed. ENIAC is generally acknowledged to be the first successful high-speed electronic digital computer (EDC) and was productively used from 1946 to 1955. A controversy developed in 1971, however, over the patentability of ENIAC's basic digital concepts, the claim being made that another U.S. physicist, John V. Atanasoff, had already used the same ideas in a simpler vacuum-tube device he built in the 1930s while at Iowa State College. In 1973, the court found in favor of the company using Atanasoff claim and Atanasoff received the acclaim he rightly deserved.
"A Brief History Of Computers"
Computers truly came into their own as great inventions in the last two decades of the 20th century. But their history stretches back more than 2500 years to the abacus: a simple calculator made from beads and wires, which is still used in some parts of the world today. The difference between an ancient abacus and a modern computer seems vast, but the principle—making repeated calculations more quickly than the human brain—is exactly the same. What is Computer Program?
As you can read in our long article on computer history, the first computers were gigantic calculating machines and all they ever really did was "crunch numbers": solve lengthy, difficult, or tedious mathematical problems. Today, computers work on a much wider variety of problems—but they are all still, essentially, calculations. Everything a computer does, from helping you to edit a photograph you've taken with a digital camera to displaying a web page, involves manipulating numbers in one way or another.
Suppose you're looking at a digital photo you just taken in a paint or photo-editing program and you decide you want a mirror image of it (in other words, flip it from left to right). You probably know that the photo is made up of millions of individual pixels (colored squares) arranged in a grid pattern. The computer stores each pixel as a number, so taking a digital photo is really like an instant, orderly exercise in painting by numbers! To flip a digital photo, the computer simply reverses the sequence of numbers so they run from right to left instead of left to right. Or suppose you want to make the photograph brighter. All you have to do is slide the little "brightness" icon. The computer then works through all the pixels, increasing the brightness value for each one by, say, 10 percent to make the entire image brighter. So, once again, the problem boils down to numbers and calculations.
What makes a computer different from a calculator is that it can work all by itself. You just give it your instructions (called program) and off it goes, performing a long and complex series of operations all by itself. Back in the 1970s and 1980s, if you wanted a home computer to do almost anything at all, you had to write your own little program to do it. For example, before you could write a letter on a computer, you had to write a program that would read the letters you typed on the keyboard, store them in the memory, and display them on the screen. Writing the program usually took more time than doing whatever it was that you had originally wanted to do (writing the letter). Pretty soon, people started selling programs like word processors to save you the need to write programs yourself.
Today, most computer users buy, download, or share programs like Microsoft Word and Excel. Hardly anyone writes programs any more. Most people see their computers as tools that help them do jobs, rather than complex electronic machines they have to pre-program—and that's just as well, because most of us have better things to do than computer programming.
What is an operating system?
Suppose you're back in the late 1970s, before off-the-shelf computer programs have really been invented. You want to program your computer to work as a word processor so you can bash out your first novel—which is relatively easy but will take you a few days of work. A few weeks later, you tire of writing things and decide to reprogram your machine so it'll play chess. Later still, you decide to program it to store your photo collection. Every one of these programs does different things, but they also do quite a lot of similar things too. For example, they all need to be able to read the keys pressed down on the keyboard, store things in memory and retrieve them, and display characters (or pictures) on the screen. If you were writing lots of different programs, you'd find yourself writing the same bits of programming to do these same basic operations every time. That's a bit of a programming chore, so why not simply collect together all the bits of program that do these basic functions and reuse them each time?
That's the basic idea behind an operating system: it's the core software in a computer that (essentially) controls the basic chores of input, output, storage, and processing. You can think of an operating system as the "foundations" of the software in a computer that other programs (called applications) are built on top of. So a word processor and a chess game are two different applications that both rely on the operating system to carry out their basic input, output, and so on. The operating system relies on an even more fundamental piece of programming called the BIOS (Basic Input Output System), which is the link between the operating system software and the hardware. Unlike the operating system, which is the same from one computer to another, the BIOS does vary from machine to machine according to the precise hardware configuration and is usually written by the hardware manufacturer. The BIOS is not, strictly speaking, software: it's a program semi-permanently stored into one of the computer's main chips, so it's known as firmware (it is usually designed so it can be updated occasionally, however).
wireless LAN - Computer Definition
(wireless Local Area Network) A communications network that provides connectivity to wireless devices within a limited geographic area. "Wi-Fi" is the universal standard for wireless networks and is the wireless equivalent of wired Ethernet networks. In the office, Wi-Fi networks are adjuncts to the wired networks. At home, a Wi-Fi network can serve as the only network since all laptops and many printers come with Wi-Fi built in, and Wi-Fi can be added to desktop computers via USB.
Wi-Fi is achieved with a wireless base station, called an "access point." Its antennas transmit and receive a radio frequency within a range of 30 to 150 feet through walls and other non-metal barriers.
Central Processing Unit
Next to the CPU sits the cache, or the temporary memory where things you are working on sit for quick interpretation by the CPU. The RAM chip is also near this location. Random-access memory is volatile, or temporary, memory. Whenever you turn on a program, its instructions are stored in RAM while the machine is on. Once you shut the machine down, both the cache and the RAM are completely cleared out. RAM storage is common at eight, ten or twelve gigabytes.
A device containing a transducer that converts electrical signals (electric current) into sound waves (acoustic energy) for the production of sound.
A device that converts analog audio signals into the equivalent air vibrations in order to make audible sound. When CRT monitors were the norm, speakers designed for computers were shielded to avoid magnetic interference with the CRT's magnetic coil. Getting Smaller All the Time Starting in the 1990s, vendors began to offer higher-quality computer speakers. Similar to home theater and stereo systems, the systems include a pair of small speakers for the midrange and high (treble) frequencies and a large subwoofer for the low end (bass). The small speakers are placed in a left/right stereo orientation, while the subwoofer can be located anywhere on the floor because bass signals are omnidirectional.
The motherboard and circuitry need to have power. There is a power box included with your system unit, and you'll see a cord coming out of the back of your computer for that. The central processing unit, or the brains of the computer, sits on the motherboard and does actually have its own cooling fan. The processors now are so fast they need to be cooled down. All the instructions you give the computer - like a click of a mouse - go through the CPU, which processes in billions of cycles per second. Commonly installed processors have quad-cores, or four separate processors in one component. There are six-core and eight-core available, and the more advanced the technology the higher the cost. That's one of the choices you might need to make.
Memory, Cache, RAM, ROM
Next to the CPU sits the cache, or the temporary memory where things you are working on sit for quick interpretation by the CPU. The RAM chip is also near this location. Random-access memory is volatile, or temporary, memory. Whenever you turn on a program, its instructions are stored in RAM while the machine is on. Once you shut the machine down, both the cache and the RAM are completely cleared out. RAM storage is common at eight, ten or twelve gigabytes.
ROM, or read-only memory, is located here as well. This is a permanent, or non-volatile, memory. As soon as you turn on your computer, the start-up instructions that are stored in ROM begin to execute. Even when you turn it off, the instructions stored in ROM remain. So if you have a machine that runs Windows, as soon as you hit the power-up button, you'll get a short screen that might give you a message from the manufacturer. Then in the background you'll just see black and the Windows logo come through, and it will say 'Starting Windows.' What's going on there is that as soon as you hit the power button, your ROM is kicking in and starting up all those instructions for systems checks.
The part attached to the motherboard you're most likely to recognize is the hard drive. The hard drive doesn't sit directly on the motherboard, but it is connected to the circuitry by electrical wire. The hard drive stores software you've put in there like Firefox, WordPad or a music player. It also stores the data files those programs have created and used. Hard drive storage commonly begins at one terabyte now and goes up to two and a half terabytes.
SPEAKER
A device containing a transducer that converts electrical signals (electric current) into sound waves (acoustic energy) for the production of sound.
"Only a Trivia"
Who invented the computer?
We could arue that the first computer was the abacus or its descendant, the slide rule, invented by William Oughtred in 1622. But the first computer resembling today's modern machines was theAnalytical Engine, a device conceived and designed by British mathematician Charles Babbage taxes.
between 1833 and 1871. Before Babbage came along, a "computer" was a person, someone who literally sat around all day, adding and subtracting numbers and entering the results into tables. The tables then appeared in books, so other people could use them to complete tasks, such as launching artillery shells accurately or calculating
It was, in fact, a mammoth number-crunching project that inspired Babbage in the first place [source: Campbell-Kelly]. Napoleon Bonaparte initiated the project in 1790, when he ordered a switch from the old imperial system of measurements to the new metric system. For 10 years, scores of human computers made the necessary conversions and completed the tables. Bonaparte was never able to publish the tables, however, and they sat collecting dust in the Académie des sciences in Paris.
In 1819, Babbage visited the City of Light and viewed the unpublished manuscript with page after page of tables. If only, he wondered, there was a way to produce such tables faster, with less manpower and fewer mistakes. He thought of the many marvels generated by the Industrial Revolution. If creative and hardworking inventors could develop the cotton gin and the steam locomotive, then why not a machine to make calculations [source: Campbell-Kelly]?
Babbage returned to England and decided to build just such a machine. His first vision was something he dubbed the Difference Engine, which worked on the principle of finite differences, or making complex mathematical calculations by repeated addition without using multiplication or division. He secured government funding in 1824 and spent eight years perfecting his idea. In 1832, he produced a functioning prototype of his table-making machine, only to find his funding had run out.
But, as you might have guessed, the story doesn't end there.
Word Origin and History for camera 1708, "vaulted building," from Latin camera "vaulted room" (source ofItalian camera, Spanish camara, French chambre), from Greek kamara"vaulted chamber."
The word also was used early 18c. as a short form of Modern Latin camera obscura "dark chamber" (a black box with a lens that could project imagesof external objects), contrasted with camera lucida (Latin for "lightchamber"), which uses prisms to produce on paper beneath the instrumentan image, which can be traced. It became the word for "picture-takingdevice" when modern photography began, c.1840 (extended to televisionfilming devices 1928). Camera-shy is attested from 1890. Old ChurchSlavonic komora, Lithuanian kamara, Old Irish camra all are borrowingsfrom Latin.
