2Introduction to Computers We are living in an information age dependent upon digital information. Digital information is electronic information, the result of computer processing. Every type of job relies upon getting information, using it, managing it, and relaying information to others. Computers enable the efficient processing and storage of information.Do not think of a computer merely as the machine with the keyboard and the mouse, although that might be true for some types of computers. Embedded computers may be inside your household appliances, the VCR, the automobile, planes, trains, powerplants, water purification plants, calculators, and even inside a few toys. These embedded computers are very small. They affect our lives each day. Why, even modern traffic lights operate with computers. They are all around us. Think of additional ways in which computers affect our lives each day.
3Computer TypesComputers are showing up everywhere you look, and even in places you can't see. Computers check out your groceries, pump your gas, dispense money at the ATM, turn the heat on and off, control the way your car runs. They're everywhere! They're everywhere!
4What is a ComputerA computer is an electronic device that executes the instructions in a program. A computer has four functions:a. accepts data Inputb. processes data Processingc. produces output Outputd. stores results StorageIn the lessons that follow we will study the parts of the computer and each of the four parts of the Information Processing Cycle.
5Some Beginning Terms Hardware : The physical parts of the computer. Software : The programs (instructions) that tell the computer what to doData : individual facts like first name, price, quantity orderedInformation : data which has been massaged into a useful form, like a complete mailing addressDefault : The original settings; what will happen if you don't change anything.
6What makes a computer powerful? Speed A computer can do billions ofactions per second.Reliability Failures are usually due tohuman error, one way or another.(Blush for us all!)Storage A computer can keep hugeamounts of data.
7Computer Types Personal or Microcomputers Computers for personal use come in all shapes and sizes, from tiny PDAs (personal digital assistant) to hefty PC (personal computer) towers. More specialized models are announced each week - trip planners, expense account pads, language translators... Laptop/NotebookTablet PCHand-held (HPC)PDADesktopTowerWorkstation
8Computer Types (cont…) Personal or MicrocomputersWhen talking about PC computers, most people probably think of the desktop type, which are designed to sit on your desk. (Bet you figured that one out!) The tower and the smaller mini-tower style cases have become popular as people started needing more room for extra drives inside. Repairmen certainly appreciate the roominess inside for all the cables and circuit boards ... and their knuckles.A workstation is part of a computer network and generally would be expected to have more than a regular desktop PC of most everything, like memory, storage space, and speed.
9Computer Types (cont…) Personal or MicrocomputersThe market for the smallest PCs is expanding rapidly. Software is becoming available for the small types of PC like the palmtop (PPC) and handheld (HPC). This new software is based on new operating systems like Windows CE (for Consumer Electronics). You may find simplified versions of the major applications you use. One big advantage for the newer programs is the ability to link the small computers to your home or work computer and coordinate the data. So you can carry a tiny computer like a PalmPilot around to enter new phone numbers and appointments and those great ideas you just had. Then later you can move this information to your main computer.With a Tablet PC you use an electronic stylus to write on the screen, just like with a pen and paper, only your words are in digital ink. The Tablet PC saves your work just like you wrote it (as a picture), or you can let the Hand Recognition (HR) software turn your chicken-scratches into regular text.
10Computer Types (cont…) Main frameThe main frame is the workhorse of the business world. A main frame is the heart of a network of computers or terminals which allows hundreds of people to work at the same time on the same data. It requires a special environment - cold and dry
11Computer Types (cont…) SupercomputersThe supercomputer is the top of the heap in power and expense. These are used for jobs that take massive amounts of calculating, like weather forecasting, engineering design and testing, serious decryption, economic forecasting, etc.The first Cray supercomputer was introduced in 1976
12Computer Types (cont…) Distributed or Grid ComputingThe power needed for some calculations is more than even a single supercomputer can manage. In distributed computing using a PC grid many computers of all sizes can work on parts of the problem and their results are pooled. A number of current projects rely on volunteers with computers connected to the Internet. The computers do the work when they are not busy otherwise. The projects that need distributed computing are highly technical. For example, the project looks for signs of intelligent communication in radio signals coming from space. (SETI stands for Search for Extra-Terrestrial Intelligence.) If you volunteer your computer for this project, you might be asked to load a small screen-saver program onto your own computer. When the computer is not busy, the screen saver comes on. The program downloads some signal data, starts to analyze it, and later reports the results back to Once the program is installed, you do not have to do anything else but watch the progress in the screen saver. Another method does not use a screen saver, but uses any idle time on your computer to work on the project. Results are sent to the project's home over the Internet.
13Other Important Terms Server The term server actually refers to a computer's function rather than to a specific kind of computer. A server runs a network of computers. It handles the sharing of equipment like printers and the communication between computers on the network. For such tasks a computer would need to be somewhat more capable than a desktop computer. It would need:more powerlarger memorylarger storage capacityhigh speed communications
14Other Important Terms Minicomputer The minicomputer has become less important since the PC has gotten so powerful on its own. In fact, the ordinary new PC is much more powerful than minicomputers used to be. Originally this size was developed to handle specific tasks, like engineering and CAD calculations, that tended to tie up the main frame.
15Other Important Terms Microcontrollers or Embedded Computers The smallest class of computers.Are the type of computer processors found in small• machines and appliances, such as microwave ovens.
16Operating SystemsA computer operating system acts like a manager or supervisor of a PC. The operating system, or OS for short, manages your computer’s resources such as your PC’s memory.Computer operating systems are generally classified as being either a GUI, i.e. graphical user interface, type or a command driven type.Popular operating systems which are GUI types include: Windows 2000 Me, Windows NT and OS / 2. Popular operating systems, which are command driven types include: DOS, which stands for Disk Operating System, and UNIX.The GUI operating systems work using a “ point and click ” environment since users are able to use pointing devices such as a mouse to select icons which are used to open programs or files.
17Operating SystemsThe command driven operating systems work using commands, which the user must be familiar with, in order to run some program or perform some other task. For example, passwd is a common UNIX command, which allows the user to change a login password.Operating systems software should be distinguished from applications software. Applications software cannot run without operating system software.Applications software includes word processors, spreadsheets, Web browsers, encyclopedia software, almanacs, entertainment software and others.
18Operating Systems Popular Computer Operating Systems Windows Server 2003 MeWindows XPWindows 2000Windows 98Windows NTOS / 2MAC OSDOSUNIXLINUXNetWare