Academic Of Information Computer
12.2B.37
English Assignment Group
“Introduction of Computer ”
GROUP 1
1.YANDI ALAUDIN (12130102)
2.HARYANTO (12130231)
3.DEDI SUGIYANTO (12130298)
4.MUHAMAD KAHFI W (12130354)
5.ARIS SUGIANTO (12130361)
Introduction to Computers
Many people believe that knowing how to use a computer, is one of the basic skills needed to succeed in the workplace. In order to use the computer it is necessary to understand how the computer works.
1.Hardware
Computer hardware is made up of the equipment used to make up you computer unit. These parts include your monitor, central processing unit (CPU), keyboard, mouse, printer, and modem.
The computer is an electronic machine that performs the following four general operations:
• Input
• Storage
• Processing
• Output
Input
The input hardware allows you to enter data into the computer. The primary devices used are the keyboard and mouse.
Keyboard - The keyboard looks like the typewriter. A numeric keypad is located to the right of the keyboard. Numeric keys have the same placement as a 10-key calculator, which allow the operator to enter data rapidly.
Mouse - The mouse is a device that allows you to control the movement of the insertion point on the screen. The operator places the palm of the hand over the mouse and moves it across a mouse pad, which provides traction for the rolling ball inside the device. Movement of the ball determines the location of the I beam on the computer screen. When the operator clicks the mouse the I beam becomes an insertion point which indicates the area you are working on the screen. You can also click the mouse and activate icons or drag to move objects and select text. There are other input devices, such as touch screen, joystick, modem, scanner, and voice recognition systems.
Processing
The central processing unit or (CPU) is the "brain" of your computer. It contains the electronic circuits that cause the computer to follow instructions from ROM (read only memory) or from a program in RAM (random access memory). By following these instructions information is processed. The CPU contains three parts.
1. Arithmetic Logic Unit - ALU is where the "intelligence" of the computer is located. It can add and compare numbers. To multiply 2 x 4 the computer would add 2 + 2 + 2 + 2. The ALU makes decisions by determining if a number is greater, less, or equal to the other number. Processing is completed in nanoseconds, which is a billionth of a second.
2. Memory - Two types of memory contained on a chip are RAM (Random Access Memory) or ROM (Read Only Memory). ROM memory has been installed on your computer by the manufacturer and can not be altered. ROM is the memory that determines all the basic functions of the operation of your machine, such as startup, shut down, and placing a character on the screen. RAM is temporary memory, which displays the information you are working on. RAM remembers what you see on your screen while you are working. Today's applications required large amounts of temporary memory, which may require you to upgrade and add more RAM memory.
3. Control Unit - This is the part of the unit, which directs information to the proper places in your computer, such as calculation of information by the ALU unit or to store and print material.
Output
Output devices such as a monitor or printer make information you input available for you to view or use.
A monitor's front is called a screen with a cathode ray tube (CRT) attached to the screen. Portable computers use a (LCD) liquid crystal display. Today's super video graphics array (SVGA) monitors display 256 sharp and clear colors.
Printers used with computers fall into two categories, impact or nonimpact. Impact printers, such as dot matrix print by contact against a ribbon making imprint on paper. Inkjet printers print images by not touching the paper. Ink jet printers spray ink onto the page while a laser printer works like a copying machine. Laser printers print a higher quality product but cost from $500 to $10,000 whereas an ink jet produces better quality than a dot matrix and can be purchased from $150 to $300. The personal computer user most commonly purchases an ink jet printer for home use.
Storage
Auxiliary storage devices, also called secondary storage devices, are used to store instructions and data when they are not being used in memory. Two types of auxiliary storage more often used on personal computers are floppy disks and hard disks. Also, CD-ROM drives are common.
Floppy Disks - A floppy disk is a circular piece of oxide-coated plastic that stores data as magnetic spots. Personal computers most commonly use floppy disks that are 3 inches in diameter.
To read data stored one floppy disk or to store data on a floppy disk, you insert the floppy disk in a disk drive. If the disk is unused, you must format or initialize it before your computer will allow you to store data on it. Formatting organizes the tracks around the disk into pie like slices called sectors which make it possible for your computer to save and retrieve information. The density of the bits on the track and number of tracks on a disk determine the number of characters that can be stored.
Floppy disks are identified as being double density or high density. Most machines purchased after 1993 will use a high-density disk. A machine that has a double density drive can't process a high-density disk. Note the chart below for disk information.
Floppy Disk Capacity
Description Bytes
5 � inch disk
Double-sided, double-density 360 KB
Double-sided, high-density 1.2MB
3 � inch disk
Double-sided, double-density 720 KB
Double-sided, high-density 1.4 MB
1.4 MB is equal to 500 pages of text.
Floppy disks must be handled with care to preserve data. Follow the suggestions to protect your floppy disk.
1. Store in box or disk storage container.
2. Protect disk from dust.
3. Keep disk out of sunlight and away from extremes of hot or cold.
4. Don't press hard when writing on labels. Use a felt tip pen.
5. Insert metal side into drive first with the hub of the disk down.
6. Don't store disk near magnetic sources.
Hard Drive - Much like a floppy, the hard disk located inside the computer case is made of a stack of rotating disks, called platters. Data is recorded on a series of tracks that have been divided into sectors. Most computers have one hard drive, located inside the computer case. If a computer has one hard drive, it is called drive C. If a computer has additional hard drives, they are called drives D, E, and so on. A hard drive stores your programs. When you buy a new program, you must install the program files to your hard drive before you can use the program. A hard drive stores your data files such as documents spreadsheets, and graphics.
CD-ROM Storage - Since each CD-ROM can store 600 million bytes of data or 300,000 pages of text, they are today's answer to make you computer feel like a machine twice its size. Because of its external storage, you can use your machine to access an encyclopedia, games, graphics, and a variety of sources that use large amounts of memory.
Bits and Bytes
A computer stores data in units called bits and bytes. Computer chips called integrated circuits have one of two states, off or on. Therefore, a system was developed that used only two numbers, 0 and 1. Zero representing off and 1 representing on. You can think of this as a sort of light switch. Each switch is called a bit.
Bits are grouped together in sets of eight. Each set of eight bits is called a byte. Setting different combinations of those eight "on and off" combinations can be developed to stand for letters numbers, spaces, and symbols. For practical purposes, think of a byte as one character. When computers refer to memory or storage they refer to terms using the following forms of measurement.
8 bits = 1 byte
1024 bytes = 1 Kilobyte (K)
1024 Kilobytes = 1 Megabyte (MG)
1024 Megabytes = 1 Gigabyte (GB)
Today's hard drives are usually two or more gigabytes of memory and a floppy disk has 1.44 megabytes of memory.
Software
Computer productivity is determined by programs which are step by step instructions telling the computer how to process data. Software can be divided into two groups, system and application.
System software - The operation of your computer is controlled by system software. As you boot the computer, the system software is stored in the computer's memory which instructs the computer to load, store, and execute an application.
Examples of system software are Windows 95 and Windows 98 which use a graphical user interface (GUI) that provides visual clues (icons) to help the user. DOS, another disk operating system, is text based and not user friendly.
Professional programmers write a variety of application software to satisfy needs of the public who wants to perform specific tasks on their computers. The basic types of application software are word processing, database, spreadsheet, desktop publishing, and communication.
Word Processing - Word processing is the most commonly used software in schools, home, and business. A key advantage of word processing software is that users can make changes such as spelling, margins, additions, deletions, and movement of text. A beginning computer student should learn word processing, as it is the basis of most software. Once you have learned how a word processor functions, you will be able to learn other software quicker.
Database Software - Database software allows us to store and manipulate large quantities of data using the computer. For example, a database can sort the names, addresses, grades and activities for all of the students in a school. It would be possible to add or delete data and produce printed reports using the database.
Spreadsheet Software - Spreadsheets store numeric data that can be used in calculations. A spreadsheet is used to store a teachers grades and then calculate student averages. The primary advantage of a computerized spreadsheet is its ability to redo the calculations should the data it stores be changed. Calculations can be made automatically as formulas have been preset into the spreadsheet.
Desktop Publishing - Desktop publishing applications allow the user to create newspapers, newsletters, brochures, and similar types of publications. It is similar to word processing except it allows the user to use text, graphics, pictures, lines, shapes, patterns, and borders. Desktop publishing requires more skill and computer knowledge of design and layout.
Presently a user can purchase an integrated program. This means that a single program performs all applications and allows data to be transferred from one application to another. Microsoft Office 97, Works, and ClarisWorks are examples of integrated software. Each application includes a word processing, data base and spreadsheet section of the software.
There are numerous other applications available. There are software programs that can be used by musicians to produce musical scores and play them on a synthesizer, programs that assist an architect in designing a building, programs that produce the special effects that you see in movies, and programs that allow e-mail or electronic mail. Every line of work you can think of has had applications developed, which can ease or enhance its effectiveness and consistency.
Communications
Computers can be connected to multimedia, such as sound graphics, photographs, and video equipment to manipulate, input, and generate output, but special software is required.
If a personal computer is within 1,000 feet of another computer, a cable can directly connect it. If the devices are more than 1,000 feet, the electrical signal weakens. Then a modem is used. A computer is designed to process data as digital signals, individual electrical pulses grouped together to represent characters. Telephone equipment was designed to carry voice, which is made up of a continuous electrical wave called an analog signal. The purpose of a modem is to send the converted digital signals of a computer to analog signals to send and then convert the analog signals it receives to digital to send the message back to the computer. A modem may be a part of the computer or a stand-alone device that is connected to the computer and phone line.
Modems can transmit data at rates from 1,200 to 56,200 bits per second (bps) for the personal user.
Summary
Computers are rapidly changing and changing the world we live in. We used to talk about the changes made in one generation. Now we see changes from year to year. However, all computers have several parts in common:
• input devices which allow data and commands to be entered into the computer
• a means of storing commands and data
• a central processing unit which controls the processing
• a means of returning the processed information in the form of output
In general, a computer is a machine which accepts information, processes it and returns new information as output.
As you become familiar with software and hardware you will have a better understanding of technology for business ad for you home. Technology is the vast field and learning it will be a life long process.
http://literacy.kent.edu/Midwest/Materials/ndakota/complit/introbasics.html
The story of Computer
Computers have been around for quite a few years. Some of your parents were probably around in 1951 when the first computer was bought by a business firm. Computers have changed so rapidly many people can not keep up with changes. Since ancient times, people have had ways to deal with data and numbers. Early people tied knots in rope and carved marks on clay tablets to keep track of livestock and trade. Some people considered the 5000 year old ABACUS a frame with beads strung on wires to be the first true computing aid. In the mid-1600's, Blaise Pascal and his father, who was a tax officer himself, were working on taxes for the French government in Paris. The two spent hours figuring and refiguring taxes that each citizen owed. Young Blaise decided in 1642 to build an adding and subtraction machine that could aide in such a tedious and time consuming process. The machine Blaise made had a set of eight gears that worked together much like an odometer keeps track of a car's mileage. His machine encountered many of problems. For one, it was always breaking down. Second, the machine was slow and extremely costly. And third, people were afraid to use the machine thinking it might replace their jobs. Pascal later became famous for math and philosophy, but he is still remember for his role in computer technology. In his honor, there is a computer language named Pascal. The next big step for computers arrived in the 1830's when Charles Babbage decided to build a machine to help him complete and print mathematical tables. Babbage was a mathematician who taught at Cambridge University in England. He began planning his calculating machine calling it the Analytical Engine. The idea for this machine was amazingly like the computer we know today. It was to read a program from punched cards, figure and store the answers to different problems, and print the answer on paper. Babbage died before he could complete the machine. However because of his remarkable ideas and work, Babbage is know as the Father of Computers.
The next huge step for computers came when Herman Hollerith entered a contest given by the U.S. Census Bureau. The contest was to see who could build a machine that would count and record information faster. Hollerith, a young man working for the Bureau built a machine called the Tabulating Machine that read and sorted data from punched cards. The holes punched in the cards matched each person's answers to questions. For example, married, single, and divorces were answers on the cards. The Tabulator read the punched cards as they passed over tiny brushes. Each time a brush found a hole, it completed an electrical circuit. This caused special counting dials to increase the data for that answer.
Thanks to Hollerith's machine, instead of taking seven and a half years to count the census information it only took three years, even with 13 million more people since the last census. Happy with his success, Hollerith formed the Tabulating Machine Company in 1896. The company later was sold in 1911. And in 1912 his company became the International Business Machines Corporation, better know today as IBM. A more modern type computer began with John von Neumann's development of software written in binary code. It was von Neumann who began the practice of storing data and instructions in binary code and initiated the use of memory to store data, as well as programs. A computer called the EDVAC (Electronic Discrete Variable Computer) was built using binary code in 1950. Before the EDVAC, computers like the ENIAC could do only one task then they had to be rewired to perform a different task or program. The EDVAC's concept of storing different programs on punched cards instead of rewiring computers led to the computers that we know today.
Types Of Computer
The types of computers range from the Hybrid to the Analog types. The computers you come across in the daily course of your day range from laptops, palmtops and towers, to desktop computers, to name a few. But the very word "computers" reminds one of the desktop computers used in offices or homes. Different categories of computes have been devised in keeping with our varied needs.
The Types Of Computers:Analog and Hybrid (classification based on operational principle)
• Analog Computers : The analog computer is almost an extinct type of computer these days. It is different from a digital computer in respect that it can perform numerous mathematical operations simultaneously. It is also unique in terms of operation as it utilizes continuous variables for the purpose of mathematical computation. It utilizes mechanical, hydraulic, or electrical energy or operation.
• Hybrid computers : These types of computers are, as the name suggests, a combination of both Analog and Digital computers.
The Digital computers which work on the principle of binary digit system of "0" and "1" can give very precise results. But the problem is that they are too slow and incapable of large scale mathematical operation. In the hybrid types of computers the Digital counterparts convert the analog signals to perform Robotics and Process control.
Apart from this, computers are also categorized on the basis of physical structures and the purpose of their use. Based on Capacity, speed and reliability they can be divided into three categories of computers :
1. The Mainframe Computer : These are computers used by large organizations like meteorological surveys and statistical institutes for performing bulk mathematical computations. They are core computers which are used for desktop functions of over one hundred people simultaneously.
2. The Microcomputer : These are the most frequently used computers better known by the name of "Personal computers". This is the type of computer meant for public use. Other than Desktop Computer the choice ranges as follows :
o Personal Digital Computer
o Tablet PC
o Towers
o Work Stations
o Laptops
o Hand Held Computer
3. The Mini computer : Mini computers like the mainframe computers are used by business organization. The difference being that it can support the simultaneous working of up to 100 users and is usually maintained in business organizations for the maintenance of accounts and finances.
Yet another category of computer is the Super Computers. It is somewhat similar to mainframe computers and is used in economic forecasts and engineering designs.
Today life without computers is inconceivable. Usage of different types of computers has made life both smooth and fast paced.
Analog Computers :
Analog Computers and Digital computers are the two kinds of computers, the combination of which is responsible for the invention of the modern Hybrid computers.
The analog systems carry out arithmetic and logical operations by manipulating and processing data which you input such as the weight, temperature, voltage, power density, etc. But unlike the digital computer that changes all inputs to binary digits of "1" and "0", the analog computer does not change inputted data to any such sign language.
The analog computer has become obsolete type of computer these days. It is different from a digital computer as it can perform numerous mathematical operations simultaneously. The digital computers, however could not operate the more complex operations. The Analog System is also unique in terms of operation as it utilizes continuous variables for the purpose of mathematical computation. It utilizes mechanical, hydraulic, or electrical energy or operation.
Mathematical Principles Applied For The Data Processing In Analog Computers :
• Logarithm
• Summation
• Exponentiation
• Calculus
• Multiplication and Division
• Inversion
The analog computer which is a complex machine is an integration of various mechanical parts which has pipes, valves, levers, gears and several key parts which can be named as follows :
• Fixed function generators
• Operational amplifiers
• Potentiometers
• Integrators
Advantages and Disadvantages of Analog Computers :
The advantage of an analog computer is that it can simultaneously find solutions to several mathematical problems and that too while being precise unlike the digital computer. But it is not free of drawbacks. Unlike the digital computer it lacks speed of calculation. There are other functional problems which mar the efficiency of analog systems. Of these, the problems of non-linearities, temperature co-efficient, parasitic effects and noise floor are the main problems so to say.
Digital Computers :
Digital Computers are that kind of computing machines which work on the principle of binary mathematics. Digital computing machines when clubbed with Analog computers produce Hybrid computers. The digital systems work on the principle of binary mathematics. In binary mathematics all calculations are represented through "0" and "1".
You have often heard about the word "Byte", "Mega Byte", "Kilo Byte". But what is a Byte? A single Byte is a group of 8 numbers or bits represented through a code series comprising of "0" and "1" .The combination of the digital signal can solve a number of mathematical operations. It is interesting to note that the fundamentals of mathematics applied are addition, subtraction, multiplication and division. But the chief problem is that though it can solve mathematical problems at a tremendous speed, it cannot perform bulk operations simultaneously. For this purpose, digital systems by themselves cannot give very precise results. Hence, for greater efficiency, the Digital systems do not find much application.
Data Processing In Digital Computers :
Digital computers function with the help of logic circuits. A reliable oscillator helps in the proper synchronization of various logic circuits that are responsible for processing data in the digital computers. In better quality computers, the oscillation rate might even be a billion cycles per second. Operating at such high speed, it can process more than billions of logic and arithmetic problems.
Mainframe Computer :
Mainframes are computers that are the most bulky types and with the advancement of technology, they have almost become extinct. Computers are of three types - Mainframe computers, Minicomputers and Microcomputers. Mainframe computer systems can be called the predecessor of servers because they could actually support multi users though as efficiently as the servers. Usually, a main frame would occupy an entire room and could cost over million dollars.
Used for the purpose of research, engineering works, meteorological calculations, graphics and the likes, mainframes today constitutes Unix, Linux, and IBM's z/OS, OS/390, MVS, VM, and VSE. Mainframe systems were manufactured extensively throughout the 1950s and were marketed by IBM, Control Data, General Electric, NCR, UNIVAC, Honeywell, RC, and Burroughs.
The three important Features ofmainframe Computers :
• Mainframes provide for maximum I/O connectivity as they accommodate huge disc farms.
• Mainframes excel in providing maximum I/O band width. Interestingly in spite of all the connected drives connected to the mainframe system, no data blocking ever happens to mar its efficiency.
• Mainframe systems also provide for very good single thread operations.
The Mini computers are a less bulky version of the mainframe computers. Minicomputers are used by business organization. The difference being that it can support the simultaneous working of up to 100 users and is usually maintained in business organizations for the maintenance ofaccounts and finances. Besides,there are personal computers or microcomputers. The micro computers include Desktop PC s, Laptops, Handheld computers, Tablet PC s, workstations, palmtops, etc. These are the most frequently used computers.
Minicomputers :
Minicomputers, what exactly are they? If supercomputers and mainframes are considered to be the best in terms of mathematical operations then minicomputer systems succeed them. Previously,minicomputers were considered to be superior to personal systems. But these days, advancement intechnology has made minicomputers almost obsolete because the PCs today are highly advanced.
The Minicomputers were first built in in 1960s and they immediately became a huge success as 40,000 of the minicomputer systems were immediately sold of making the computers hugely available to the general public. With such a successful market possibility many companies stepped in to venture in the minicomputer market. The most successful among these two hundred companies was DEC that launched the minicomputer models PDP-11 and VAX 11/780.
Some significant aspects and historical facts about the mini computer system has been summarized as follows :
• They are much smaller in size than the mainframe computer systems. As such they do not occupy an entire room but usually occupy space similar in size to that of a standard refrigerator.
• They are much less expensive than the mainframes.
• Their invention was possible because of the invention of core memory technologies and transistors.
• Minicomputers can can give parallel access to up to 100 users. Hence they were used in places such as business organizations for maintaining billings and finances.
• Some of the very first companies to manufacture the minicomputer systems were Hewlett Packard, DEC and Data General.
A few models of minicomputers which have been a marked success over the years are :
• DEC VAX series and PDP series
• Hewlett Packard HP3000 series
• SDS,SDS-92
• Prime Computers, Prime 50 Series
• Norsk Data, Nord-1, Nord-10, Nord-100
• IBM Midrange Computers
• Control Data Corporation's CDC 160A, CDC-1700
• Data General Nova
• Honeywell-Bull Level 6/DPS Level6/DPS 6000 series
Minicomputershave eventually evolved in to microcomputers. With the launch of microcomputers, thepublic have had a greater access to the advantage of incorporating computers in the daily stride of their lives.
Supercomputers :
Supercomputers are one of the many types of modern computing machines which are capable of giving very speedy calculations. It is because of their high speed processing ability that Supercomputer systems are used in such works as animation graphics, weather forecasting, nuclear research work, petroleum research works, crypt analysis, molecular modeling and the likes. You must be wondering then what is the difference between a supercomputer and a mainframe computer system? While Mainframe machines are primarily used for a number of purposes, supercomputers are so designed to serve a singular purpose.
A brief time line ofthe development of supercomputers has been given as follows :
• 1960s : Seymour Cray of Control Data Corporation (CDC) launches the Supercomputer systems.
• 1970s : Cray Research isfounded by Seymour Cray after he leaves Control Data Corporation (CDC). Most supercomputers were meant for running vector processor.
• 1985-1990 : Cray's model of supercomputer takes over the market.
• Today, supercomputers are designed by such companies as HP, IBM and of course, Cray Inc. Supercomputer systems are now becoming almost the same as laptop computers and desktop systems.
Before the 1970s, supercomputers were mostly run on scalar process principle. But in order to improve its efficiency a number of new technologies were developed such as :
• Liquid Cooling
• Striped Disks (RAID)
• Parallel File systems
• Non-uniform memory access (NUMA)
• Vector Processing
When the hardwares of the supercomputers are prepared to serve a special mathematical operation, they are called Special Supercomputers. Currently there are many such types of supercomputers as the GRAPE for molecular dynamics and astrophysics, Deep Crack for
