1. The University of Akron Summit College Business Technology Department Computer Information Systems 2440: 145 Operating Systems Introduction to Computers Instructor: Enoch E. Damson

2. Introduction to Computers2 Computer  A machine that performs four basic operations known as the information processing cycle (input, processing, output, and storage) Input – computer gathers data from users Process – data is converted into information Storage – data or information is stored for future use Output – data or information is retrieved from the computer

3. Introduction to Computers3 Types of Computers  The four basic types of computers are: Supercomputers Mainframes Minicomputers Microcomputers

4. Introduction to Computers4 Types of Computers…  Supercomputers – fastest, most expensive, large and powerful computers for specialized tasks such as mathematical calculations, weather tracking, satellite monitoring, etc  Mainframes – large computers designed to handle huge processing jobs in large corporations and government agencies Mainframe computers multitask – perform different types of tasks at the same time  Minicomputers – handle the computer needs of smaller corporations  Microcomputers – designed to meet individual needs Some of the most common types of microcomputers are: desktops, laptop/notebook, personal digital assistants (PDAs)

5. Introduction to Computers5 Types of Microcomputers

6. Introduction to Computers6 Computer Information System (IS)  A collection of components that work together to process data into information  Components include: Hardware Software Procedures Data People Network

7. Introduction to Computers7 Computer Information System…

8. Introduction to Computers8 Hardware  The physical components of the computer controlled by the software  The way these components are put together and arranged is called system hardware configuration  Types of hardware devices (peripherals) include: Input Devices Systems Unit  Processor Unit  Internal memory Storage Devices Output Devices

9. Introduction to Computers9 Types of Hardware Devices

10. Introduction to Computers10 Input Devices  Used to enter data into the computer for processing  Examples include: Keyboard Mouse Scanner Digital camera Video camera

11. Introduction to Computers11 Keyboard  The primary input device for computers  Uses the following types of keys to send data to the computer Alphanumeric keys Control keys Function keys Cursor control keys Toggle and other keys Multimedia and Internet control keys

12. Introduction to Computers12 Keyboard Keys  Alphanumeric keys – sends alphabets and numeric values to the computer Numeric keypad – provides alternate method of quickly entering numbers  Control keys – the Ctrl, Alt, and Windows keys that are used in combination with other keys to provide shortcuts or increased keyboard functionality  Function keys – numbered F1 through F12 and generally associated with certain software-specific commands

13. Introduction to Computers13 Keyboard Keys…  Cursor control keys – arrow keys that allow users to move the insertion point  Toggle and other keys – the Insert, Num Lock, Caps Lock and other keys used for various purposes like navigation and editing  Multimedia and Internet control keys – available on most modern keyboards for functions such as muting or volume control, opening a Web browser, sending an email, etc

14. Introduction to Computers14 Keyboard Keys

15. Introduction to Computers15 System Unit  Holds the processing hardware, electrical power supply, disk drives, circuit cards, ports for connecting other hardware and the motherboard (system board) Motherboard – ties everything in the system unit together The motherboard holds two very important parts of the computer:  Processor (central processing unit (CPU) or microprocessor)  Memory (RAM)

16. Introduction to Computers16 Motherboard

17. Introduction to Computers17 The Processor  The brain of the computer that controls all the commands and tasks of the computer  Has three basic main parts: Control Unit – obtains instructions from the computer’s memory and interprets these instructions and executes them Arithmetic-Logic Unit (ALU) – performs all the arithmetic (math operations) and logical (comparisons) operations for the computer Registers – a small set of temporary storage cells used to store data and instructions needed frequently  Measured by the speed at which they are capable of processing data – also known as clock speed Processing speed is measured in megahertz (MHz) – in millions – and gigahertz (GHz) – in billions  Examples include: Pentium, Celeron, Centrino (by Intel Corporation) Athlon, Sempron, Turion (by Advanced Micro Devices)

18. Introduction to Computers18 Memory  Holds: Data – raw facts for processing Instructions – rules for processing data Information – processed data  Two basic types of memory include: Random Access Memory (RAM) – the volatile part of memory that stores information temporarily Read-Only Memory (ROM) – the nonvolatile part of memory on which instructions have been prerecorded to help start the computer and perform other tasks  Memory is measured by its size in bytes, kilobytes (thousands), megabytes (millions), and gigabytes (billions) Bit (Binary Digit) – the smallest unit of information in computers that is made up of 0s and 1s Byte – represents a single character and consists of 8 bits ASCII (American Standard Code for Information Interchange) – one of the coding schemes used to represent characters in 8-bit bytes  Can represent a maximum of 256 characters (incl. uppercase and lowercase letters, numbers, punctuation marks, and special symbols) Word – a group of bytes  System-dependent  Vary from 16 bits (2 bytes), 32 bits ( 4 bytes) or even 64 bits (8 bytes)

19. Introduction to Computers19 Storage Devices  Used to store data and information permanently  Data is generally stored using one of the following forms: Magnetic storage – uses sectors that divide tracks to store data  E.g. hard disks, tapes, floppy disks, zip disks Optical storage – also uses tracks and sectors but data is saved using a laser beam  E.g. Compact discs (CDs), digital video discs (DVDs) Flash memory – uses solid-state technology which is completely electronic and has no moving mechanical parts  E.g. Flash drives (memory sticks), cards used in digital cameras, MP3 players, etc  Storage devices are measured in bytes, kilobytes, megabytes, gigabytes

20. Introduction to Computers20 Examples of Storage Devices

21. Introduction to Computers21 Output Devices  The devices used to display and print data and information  E.g. monitor, printer, speakers, etc Monitors output soft copy and their resolution identifies the number pixels (picture elements) per square inch that appear on a screen  Most monitors today can display at least 256 colors  The two main categories of monitors are: Cathode ray tubes (CRT) – can be curved or flat and relatively inexpensive Flat-panel/LCD monitors – use liquid crystal display (LCD) technology and are much slimmer and expensive Printers output hard copy and their resolution is measured in dots per inch (dpi)  The two main categories of printers are: Impact printers – like dot matrix printers that use small keys to strike an ink ribbon against a paper Non-impact printers – like ink-jet printers and laser printers that do not touch the paper when printing

22. Introduction to Computers22 Examples of Output Devices  Monitors  Printers

23. Introduction to Computers23 Software  Software (program) - a set of instructions that direct the computer to accomplish certain tasks  The two major categories of software are: System software Application software

24. Introduction to Computers24 System Software  Provides the instructions needed for the computer to run  The ”background software” that manages the fundamental operations of a computer system including: Starting up (booting) the computer Executing programs  There are 4 types of system software: Operating systems – E.g. Windows, Mac OS, Linux Utilities programs – Norton Antivirus Device drivers – printer software Programming languages – Java, C++

25. Introduction to Computers25 Operating System  Controls basic input and output, allocates system resources, manages storage space, maintains security, and detects equipment failure  Examples include: DOS Windows UNIX Mac OS, etc

26. Introduction to Computers26 Application Software  ”End-user” software that performs useful tasks such as word processing, desktop publishing, etc  Kinds of application software include: Word processing software – e.g. Microsoft Word Spreadsheet software – e.g. Microsoft Excel Database software – e.g. Microsoft Access Presentation software – e.g. Microsoft PowerPoint Communication & Organization software – e.g. Microsoft Outlook

27. Introduction to Computers27 Procedures  Rules or guidelines for people to follow when using software, hardware, and data  E.g. Software Manuals

28. Introduction to Computers28 People  Making people more productive is what computers are all about  Examples include: Analysts Designers Developers Users

29. Introduction to Computers29 Data  Raw facts entered into the computer system for processing  Processed to produce information

30. Introduction to Computers30 Networks  Two or more computers connected in some way to share hardware, software programs, data and other resources Node – each object (computer, printer, etc) connected to a network  The two main types of networks are: Local area network (LAN) – uses direct cables, radio, or other signals to link computers within a small geographic area like a building or group of buildings Wide area network (WAN) – uses long- distance transmission media to link computers separated by a few miles or even thousands of miles

31. Introduction to Computers31 Network Configurations  The two main categories of network configurations are: Peer-to-peer (P2P) networks – most commonly found in homes and small-businesses with each node capable of communicating with every other node Client/server networks - consist of a server (host computer) and clients (workstations)

32. Introduction to Computers32 Networks Topology (Topography)  The different types of network architecture – how computers and other devices are arranged and connected  The most common topographic layouts include: Bus network – no server but each node connects to a central high-speed line (bus) Ring network – all nodes connect to a circular line around which data travels in only one direction Star network – each node connects to a centrally located switch to communicate with other nodes  The most frequently used networking style for businesses  Has a server to which all clients and other devices are connected Wireless network – devices connect to other computers and network resources using radio signals, microwaves, satellite signals, and other wireless media

33. Introduction to Computers33 Network Topologies

34. Introduction to Computers34 Network Cables  Computers can be connected to a network using devices like: Coaxial cables – typically used by most cable TV systems  The ends are usually made with RF (radio frequency) connectors Twister pair cables (shielded and unshielded) – two conductors are twisted together for the purposes of canceling out electromagnetic interference (EMI) from external sources  The ends are usually made with RJ (registered jack) 45 to plug into computer network interfaces  Two main types include: Shielded Twisted Pair (STP) cables – Unshielded Twisted pair (UTP) /Ethernet cables – primarily used for telephones and commonly for computer networking Fiber-optic cables – a glass or plastic fiber that carries light along its length  Used by most high-speed Internet cable connections Wireless – transfers information without using wires Introduction to Computers34

35. Introduction to Computers35 Coaxial Cable Introduction to Computers35

36. Introduction to Computers36 Twisted Pair Cable Introduction to Computers36 Shielded Twisted Pair (STP) Unshielded Twisted Pair (UTP)

37. Introduction to Computers37 Fiber-Optic Cable Introduction to Computers37

38. Introduction to Computers38 Ports  Where all the peripheral devices connect to the computer to enable data exchange  Because input and output devices can exchange data with the computer using different methods, they might require different ports

39. Introduction to Computers39 Types of Ports  Serial and parallel ports are two of the oldest types of ports found on a computer  Serial ports – can only send data one bit at a time Transfer data 115 Kilobits per second (Kbps) at most Devices that use serial ports include the mouse, modem  Parallel ports – send data in groups of bits, at transfer rates of up to 500 Kbps Printers often use parallel ports

40. Introduction to Computers40 Faster Types of Ports  Universal serial bus (USB) ports – able to interface with several different peripheral devices USB 2.0 can attain a rate of 480 Mbps or 480,000 Kbps  FireWire ports - usually used to connect digital cameras or digital video recorders to a computer  Connectivity ports – used to connect to a local network or to the Internet Examples include:  Modem ports – resemble phone jacks and are used to connect the modem to a phone system and enable dial-up Internet access  Ethernet port - a bit larger than the standard phone jack and used for network access and can also be used to connect a cable modem or router

41. Introduction to Computers41 Types of Ports