Why is it important to know how a computer works? Easy, if you don't, it will be hard to control. Computers were never built to control us even though that is how it appears. Their creation was just another tool God gave man to use to benefit society. What can you do to learn more about computers? I have an easy answer. Just read, and use computers more. They are not that hard and with time you too can become the master over this tool. Computers, the ones we know and love have not been around all that long. The first home personal computer was not sold until 1977. We have come a long way since then. Did you know that in 1983 there were approximately 2 million personal computers in use in the United States. However just 10 years later in 1993 the number had jumped to more than 90 million. Computers, today are small, fast, reliable, and extremely useful. Back in 1977 that really was not the case. However, they both operated in basically the same way. They both receive data, stored data, processed data, and then output data similar the the way our own brain functions. This article deals with those 4 functions: Memory, Processing, Input, and Output. MemoryLets look at computer memory first. The function of storage in a computer comes in many different sizes, types and shapes. However there are two basic categories: short-term and long-term. A typical computer contains numerous types of memory including RAM, ROM, virtual, cache, and various long-term storage devices. Each type of computer memory serves a specific function and purpose. Computer memory is measured in bytes. A single byte is made up of a series of 1's and 0's normally traveling in pairs of eight. These eight 0's and 1's are the way the computer communicates and stores information. With each keystroke or character a byte of memory is used. In another article you will learn more about bits and how the computer thinks. Measuring MemoryTerm/Byte Abbreviation ValueKilo K, KB 1,024 bytesMega M, MB, Meg 1,048,576 bytes (Million)Giga G, GB, Giga 1,073,741,824 bytes (Billion)Tera T, TB, Tera 1,099,511,628,000 bytes (Trillion)Here is another way of looking at the measurement of memory: Measuring Bytes8 bits = 1 byte1000 bytes = 1 kilobyte1000 kilobytes = 1 megabyte1000 megabytes = 1 gigabyte1000 gigabytes = 1 terabyte ROM ROM, or read-only memory is permanent, long-term, nonvolatile memory. Nonvolatile means is doesn't disappear when the computer is shut off. It also can not be erased or changed in anyway. However there are types of ROM called PROM that can be altered. The P stands for programmable. ROM's purpose is to store the basic input/output system (BIOS) that controls the start-up, or boot process. RAMRAM, or random-access memory unlike ROM works only when the computer is turned on. This memory is vital to the computer because it controls the moment by moment processes of the computer. The first thing that goes into RAM is the OS (operating system) which is most cases is Windows 95. Next for the RAM might be a game, or the Internet browser, or some type of software that you want to use. Early personal computer only needed about 64K of RAM. Today that number is drastically higher. With photos, sounds, and even movies going into RAM, the amount need is now in the millions. The computer I am currently using has 80 MB or 80,000K of RAM. Multitasking has put more demand on RAM in the past few years. Multitasking is the ability to run more than one program at the same time. For instance, many people like to run Netscape Communicator along with their word processing software. This means you need lots of RAM to hold both programs. Other types of temporary memory are cache (pronounced "cash") and virtual memory. Both of these types of memory supplement the computer's primary RAM and perform the same function as RAM. Storage Devices: RAM and ROM may be very important parts of the computer; however, without storage devices like hard drives and disk drives your computer would not be near as useful. Here are the most common forms of Storage Devices found on your home computer: Floppy disk or Floppy Hard disk (drive) or HDA round plastic surface that is coated with magnetic film. They come in 31/2 size. They hold about 720k to 1440K of information. They are typically are used to install new software, save, share, and/or copy files. Floppy drives are given letters. Commonly the floppy is A, a 2nd floppy is B and the hard drive is C. A stack of round metal platters called disks encased in a metal air tight shell. They commonly range in sizes from 1 to 10 gigabytes (1000MB=1GB). The hard drive's function is to store all the files, and software the computer will ever use. Any file or software program used by RAM most likely will come from the disk drive. CD-ROM (Compact disk, read-only memory) DVD-ROM (digital video disk, read-only memory)CD's function much like hard drive in that they store large amounts of memory. What separates them is their mobility and optical storage technology. Their storage capacity is also very limited compared to hard drives. The can only hold up to approximately 650 MB of information. The other big difference is that you have to have a special drive to write to CD's. Otherwise they can only be read from. DVD's are similar to CD in that they are written and read by laser. Hard drives use magnetic currents store data. However CD's and DVD's use light (laser) to write and read data on a disk. These long and short pits are then stored or etched on the surface of the disk. They can only be read by laser technology. The new DVD technology increased the amount of memory a regular CD can hold. DVD's can range in sizes from 4.34GB (1000MB=1GB) to 7.95GB.ProcessingIf someone had to find the brains of the computer they would most certainly say its the microprocessor. The microprocessor is often referred to as the CPU (Central processing unit). The microprocessor is a chip the size of a postage stamp. The processor is the one part of the computer that is most important to the computer. The microprocessor controls how data is sorted and directs the flow of data. To a great extent a computer is defined by the power of its microprocessor. Chips with higher processing speed and more recent design offer the greatest performance and access to new technologies. Most microprocessors made for PCs are made by Intel or by companies that clone Intel chips, such as Advanced Micro Devices (AMD) and Cyrix. The early Intel chip came in models called 286, 386, and 486. The 586 chip was given the name Pentium. The series of Pentiums were given the following names: Pentium Pro, Pentium with MMX, and Pentium II. The newer processors hold more transistors and thus more computing power on a single chip. MicroprocessorProcessor No. of Transistors Bus Width80286 134,000 16 bit80386 275,000 32 bit80486 1,600,000 32 bitPentium 3,300,000 64 bit external/ 32 bit internalPentium Pro 5,500,000 64 bitPentium w/ MMX 4,500,000 64 bit external/ 32 bit internalPentium II 7,500,000 64 bitInputOne of the best features of a computer is the ability to give the computer commands and feed it information. Without an input device this would not be possible. Input devices can be built into the computer, like the keyboard in a laptop, or it can be connected to the computer by a cable. The most common input device is the keyboard. There are lots of others such as: mice, trackballs, touch pads, touch screens, pens, joy sticks, scanners, bar code readers, video and digital cameras, and microphones. In addition, storage devices such as disk drives can serve as input devices. OutputInput is important but equally important is the ability to read what the computer is doing. The computer output devices are used to serve the user. The most common output device is the monitor, or screen. However most computer come with speakers and a printer which are excellent output devices. Storage devices such as disk drives and diskettes also serve as output devices when it is necessary to write new or updated data files toIn the beginning ... A generation refers to the state of improvement in the development of a product. This term is also used in the different advancements of computer technology. With each new generation, the circuitry has gotten smaller and more advanced than the previous generation before it. As a result of the miniaturization, speed, power, and memory of computers has proportionally increased. New discoveries are constantly being developed that affect the way we live, work and play. The First Generation: 1946-1958 (The Vacuum Tube Years) The first generation computers were huge, slow, expensive, and often undependable. In 1946two Americans, Presper Eckert, and John Mauchly built the ENIAC electronic computer which used vacuum tubes instead of the mechanical switches of the Mark I. The ENIAC used thousands of vacuum tubes, which took up a lot of space and gave off a great deal of heat just like light bulbs do. The ENIAC led to other vacuum tube type computers like the EDVAC (Electronic Discrete Variable Automatic Computer) and the UNIVAC I (UNIVersal Automatic Computer). The vacuum tube was an extremely important step in the advancement of computers. Vacuum tubes were invented the same time the light bulb was invented by Thomas Edison and worked very similar to light bulbs. It's purpose was to act like an amplifier and a switch. Without any moving parts, vacuum tubes could take very weak signals and make the signal stronger (amplify it). Vacuum tubes could also stop and start the flow of electricity instantly (switch). These two properties made the ENIAC computer possible. The ENIAC gave off so much heat that they had to be cooled by gigantic air conditioners. However even with these huge coolers, vacuum tubes still overheated regularly. It was time for something new. The Second Generation: 1959-1964 (The Era of the Transistor) The transistor computer did not last as long as the vacuum tube computer lasted, but it was no less important in the advancement of computer technology. In 1947 three scientists, John Bardeen, William Shockley, and Walter Brattain working at AT&T's Bell Labs invented what would replace the vacuum tube forever. This invention was the transistor which functions like a vacuum tube in that it can be used to relay and switch electronic signals. There were obvious differences between the transisitor and the vacuum tube. The transistor was faster, more reliable, smaller, and much cheaper to build than a vacuum tube. One transistor replaced the equivalent of 40 vacuum tubes. These transistors were made of solid material, some of which is silicon, an abundant element (second only to oxygen) found in beach sand and glass. Therefore they were very cheap to produce. Transistors were found to conduct electricity faster and better than vacuum tubes. They were also much smaller and gave off virtually no heat compared to vacuum tubes. Their use marked a new beginning for the computer. Without this invention, space travel in the 1960's would not have been possible. However, a new invention would even further advance our ability to use computers. The Third Generation: 1965-1970 (Integrated Circuits - Miniaturizing the Computer) Transistors were a tremendous breakthrough in advancing the computer. However no one could predict that thousands even now millions of transistors (circuits) could be compacted in such a small space. The integrated circuit, or as it is sometimes referred to as semiconductor chip, packs a huge number of transistors onto a single wafer of silicon. Robert Noyce of Fairchild Corporation and Jack Kilby of Texas Instruments independently discovered the amazing attributes of integrated circuits. Placing such large numbers of transistors on a single chip vastly increased the power of a single computer and lowered its cost considerably. Since the invention of integrated circuits, the number of transistors that can be placed on a single chip has doubled every two years, shrinking both the size and cost of computers even further and further enhancing its power. Most electronic devices today use some form of integrated circuits placed on printed circuit boards-- thin pieces of bakelite or fiberglass that have electrical connections etched onto them -- sometimes called a mother board. These third generation computers could carry out instructions in billionths of a second. The size of these machines dropped to the size of small file cabinets. Yet, the single biggest advancement in the computer era was yet to be discovered. The Fourth Generation: 1971-Today (The Microprocessor) This generation can be characterized by both the jump to monolithic integrated circuits(millions of transistors put onto one integrated circuit chip) and the invention of the microprocessor (a single chip that could do all the processing of a full-scale computer). By putting millions of transistors onto one single chip more calculation and faster speeds could be reached by computers. Because electricity travels about a foot in a billionth of a second, the smaller the distance the greater the speed of computers. However what really triggered the tremendous growth of computers and its significant impact on our lives is the invention of the microprocessor. Ted Hoff, employed by Intel (Robert Noyce's new company) invented a chip the size of a pencil eraser that could do all the computing and logic work of a computer. The microprocessor was made to be used in calculators, not computers. It led, however, to the invention of personal computers, or microcomputers. It wasn't until the 1970's that people began buying computer for personal use. One of the earliest personal computers was the Altair 8800 computer kit. In 1975 you could purchase this kit and put it together to make your own personal computer. In 1977 the Apple II was sold to the public and in 1981 IBM entered the PC (personal computer) market. Today we have all heard of Intel and its Pentium® Processors and now we know how it all got started. The computers of the next generation will have millions upon millions of transistors on one chip and will perform over a billion calculations in a single second. There is no end in sight for the computer movement.
موضوع: Why is it important to know how a computer works? 
10/5/2012, 7:27 pm