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Lead Black Slide. Chapter 4. Information System Hardware. Our Agenda. Computer Organization Input and Output Devices Primary Storage The Central Processing Unit Secondary Storage. Learning Objectives. Describe the main components of the computer. List common input and output devices
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Lead Black Slide Powered by DeSiaMore
Chapter 4 Information System Hardware Powered by DeSiaMore
Our Agenda • Computer Organization • Input and Output Devices • Primary Storage • The Central Processing Unit • Secondary Storage Powered by DeSiaMore
Learning Objectives • Describe the main components of the computer. • List common input and output devices • Describe how is data represented in a computer? • Describe how primary storage is organized. Powered by DeSiaMore
Learning Objectives (cont’d.) • Describe the structure and function of the central processing unit (CPU). • Describe how is data stored and retrieved using common forms of secondary storage? Powered by DeSiaMore
Computer Organization Information System Hardware Powered by DeSiaMore
What is a computer • A computer is a device that is • Electronic • Can store data • Can store and follow a set of software instructions, called a program. Powered by DeSiaMore
Input Devices • An input device accepts data from outside the computer and converts it into an electronic form the computer can understand. • Examples include a keyboard, mouse, scanner, digital pen, and digital tablet. Powered by DeSiaMore
Output Devices • An output device converts data from an electronic form inside the computer to a form that can be used outside the computer. • Examples include a screen, monitor, printer, and fax. Powered by DeSiaMore
Primary Storage • Primary storage, also called internal storage, is the “memory”, or RAM, of the computer. • Primary storage, which is temporary storage, is dependent upon continuous electrical power. Any interruption of electrical power causes the contents of primary storage to be lost. Powered by DeSiaMore
Central Processing Unit (CPU) • The CPU, or processor, carries out the instructions of the program. It contains circuits that perform arithmetic and logical operations. • Data is transferred from primary storage to the CPU with the results sent back to primary storage. Powered by DeSiaMore
Secondary Storage • Secondary storage, also called auxiliary storage, stores data not currently being processed by the computer and represents permanent storage. • Data is usually transferred to and from primary storage. • Examples include hard disks, floppy disks, ZIP disks, CDROMs, and DVDs. Powered by DeSiaMore
Input and Output Devices Information System Hardware Powered by DeSiaMore
Keyboards • Most widely used input device. • Possible physical problems include • Repetitive strain injuries • Carpal tunnel syndrome • Ergonomically designed keyboards may improve user comfort and efficiency and reduce risk of injury. Powered by DeSiaMore
Pointing Devices • Mouse • Trackball • Trackpoint • Trackpad, also called a touchpad • Cursor Powered by DeSiaMore
Other input devices • Touch screen • Pen input • Graphics tablet • Digitizer tablet • Light pen Powered by DeSiaMore
Optical Scanning Input Devices • Bar-code scanner • Universal Product Code (UPC) • Flat bed, or page scanner • Automatic document feeder (ADF) scanner • Optical Character Recognition (OCR) • Mark-sense readers Powered by DeSiaMore
Magnetic Scanning Input Devices • Magnetic strip reader • Credit cards • ID Cards • Magnetic Ink Character Recognition (MICR) – used at the bottom of all checks by the banking industry. Powered by DeSiaMore
Voice Input Devices • Voice recognition software • Dragon Naturally Speaking • Via-Voice • Uses a microphone connected to the computer and translates the spoken word to text output. Powered by DeSiaMore
Digital Input Devices • Digital cameras that produce photographic quality images. • Cameras connected to the computer for “live” images. Powered by DeSiaMore
Screens, or Monitor, or CRT • Key elements of a “screen” include: • Pixels – picture elements arranged as a pattern of dots. • Screen resolution – the number of pixels that can be displayed on a screen at one time. • Refresh rate – the number of times per second that screen “repaints” itself. Powered by DeSiaMore
Screens, or Monitor, or CRT (cont’d.) • Types of monitors • Traditional “tube” monitors, or cathode ray tube (CRT). • Flat-panel screens – most common type is liquid crystal display (LCD). • Screen projector used to display a computers output on a large screen. Powered by DeSiaMore
Printers • Printer classifications • Impact printer • Nonimpact printer • Serial printers • Line printers • Page printers • Letter-quality printers • Draft-quality printers Powered by DeSiaMore
Desktop printers • Ink-jet, or bubble-jet printer • Typically 200 to 300 characters per second • Laser printers • Typically between 4 and 24 pages per minute. • Dot matrix printer • Typically between 200 and 300 characters per second. Powered by DeSiaMore
High volume printers • Line printers • High end line printers can print as much as 3,600 lines per minute (at 60 lines per page, that is 60 page per minute) and can cost $50,000. • Page printers • High end page printers can print as much as 200 pages per minute and can cost $100,000. Powered by DeSiaMore
Other Output Devices • Plotters • Voice output devices – converting digitized data into synthesized speech • Sound output devices – speakers • Specialized devices for people with disabilities – can include large typeface screens, Braille display devices, special pointing devices, or headphones. Powered by DeSiaMore
Virtual Reality • Virtual reality is the use of a computer to produce realistic images and sounds in such a way that the user senses that he or she is a part of the scene. • Examples include architectural design, home remodeling, aircraft design, machine design, and more. Powered by DeSiaMore
Primary Storage Information System Hardware Powered by DeSiaMore
Primary Storage Structure • Input data is stored in primary storage (memory) after it is received from an input device. • Output data is stored in primary storage before it is sent to an output device. • Without sufficient primary storage, it may not be possible to execute certain programs or use certain data. Powered by DeSiaMore
Primary Storage Structure (cont’d.) • Silicon chips – integrated circuits • Volatile storage – dependent upon continuous power • Random Access Memory (RAM) • Non-volatile storage • Read-Only Memory (ROM) Powered by DeSiaMore
Primary Storage Structure (cont’d.) • Binary representation • A combination of positive and negative electrical charges, represented by 1s and 0s when written to represent a character. • One “charge” is called a bit. • Eight bits are required to represent a single character, called a byte. • The 256 possible (28) binary combinations are defined in character set. Powered by DeSiaMore
Primary Storage Structure (cont’d.) • Personal computer character set • ASCII – American Standard Code for Information Interchange • Mainframe computer character set • EBCDIC – Extended Binary Coded Decimal Interchange Code • Though each contains 256 characters, the definitions are not the same, so a “translator” is required for one machine type to “talk” with the other machine type. Powered by DeSiaMore
Primary Storage Structure (cont’d.) • Storage locations of the “bytes” are called allocation units each of which has a unique address. • Storage capacities • Kilobyte (KB) or 1024 bytes (210) – approximately 1,000 bytes, thus the “kilo” • Megabyte (MB) or 1,048,756 bytes (220) • Gigabyte (GB) or 1,073,741,824 bytes (230) • Terabyte (TB) or 1,099,511,627,776 bytes (240) Powered by DeSiaMore
The Central Processing Unit Information System Hardware Powered by DeSiaMore
Two Main Parts of a CPU • Arithmetic-Logic Unit (ALU) • May add, subtract, multiply and divide two numbers. More complex operations are are completed by using sequences of the four basic operations. • Control Unit • Analyzes and executes instructions in a program. Instructions are brought in one at a time from primary storage. Powered by DeSiaMore
CPU Speed • Early CPUs processed 8 or 16 bits at a time. • Current CPUs process 32 bits, and some can process 64 or 128 bits at a time. • The “roadway” from primary storage to the CPU is the bus. Higher bus capacities mean faster computers. Powered by DeSiaMore
CPU Speed (cont’d.) • Clock speed • Measured in megahertz (MHz) or gigahertz (GHz). • One MHz is one million cycles per second. • One GHz is one billion cycles per second. • Earliest IBM PCs ran at 4.77 MHz. • Current PCs run at or above 1,000 MHz (1 GHz). Powered by DeSiaMore
Microcomputer Intel 4004 Intel 8088 Intel 8086 Intel 80286 Intel 80386 Intel 80486 Intel Pentium Intel Pentium Pro Intel Pentium II Intel Pentium III Apple/Macintosh Motorola 68000 Motorola 68020 Motorola 68030 Motorola 68040 Motorola Power PC G3 AMD Common CPUs Powered by DeSiaMore
Minicomputer and Mainframe Developed by the manufacturer within a “line” of products HP3000 IBM System/390 DEC Alpha Supercomputers Generally specific to a single product Common CPUs (cont’d.) Powered by DeSiaMore
Secondary Storage Information System Hardware Powered by DeSiaMore
Magnetic Disk Storage Floppy disk Hard disk ZIP disk Disk organization Disk Head (or side) Track Allocation Unit Types of Secondary Storage Powered by DeSiaMore
Optical Disk Storage • Compact disks (CDROMs) • Capacity of approximately 600MB • Writable Compact Disks (CD-RWs) • Capacity of approximately 600MB • Digital Video Disks or Digital Versatile Disks (DVDs) • Capacity of approximately 4.7GB to 17GB depending on how it is used. Powered by DeSiaMore
Magnetic Tape Storage • Magnetic tape has a capacity of 200MB to over 40GB. • Data transferred to the tape via a magnetic tape drive. • Data on a tape can only be read sequentially. Powered by DeSiaMore
Information Systems Hardware Key Terms Powered by DeSiaMore
Address Arithmetic-Logic-Unit (ALU) ASCII Backup Copy Bar-Code Scanner Binary Digit (Bit) Byte CD-R/CD-ROM/CD-RW Central Processing Unit (CPU) Chip Compact Disk Computer Control Unit VRT Cursor Disk Pack Key Terms Powered by DeSiaMore
Dot-Matrix Printer Draft-Quality Printer DVD/DVD-ROM EBCDIC Ergonomics Flat Panel Screen Floppy Disk Gigabyte (GB) Gigahertz (GHz) Hard Disk Impact Printer Input Device Ink-Jet Printer Keyboard Kilobyte (KB) Laser Printer Letter-Quality Printer Line Printer Key Terms (cont’d.) Powered by DeSiaMore
Machine Language Magnetic Disk Magnetic Disk Drive Magnetic Ink Character Recognition (MICR) Magnetic Strip Reader Magnetic Tape Magnetic Tape Drive Massively Parallel Processing Megabyte (MB) Megahertz (MHz) Microprocessor Microsecond Millisecond Monitor Mouse Key Terms (cont’d.) Powered by DeSiaMore
Multifunction Printer Multimedia Multiprocessing Nanosecond Nonimpact Printer Nonvolatile Storage Optical Disk Optical Disk Drive Output Device Page Printer Parity Bit Pen Input Peripheral Equipment Pixel Plotter Primary (Internal) Storage Printer Key Terms (cont’d.) Powered by DeSiaMore
Processor Program RAID Random Access Memory (RAM) Random (Direct) Access Read Only Memory (ROM) Scanner Screen Screen Projector Screen Resolution Secondary (Auxiliary) Storage Sequential Access Serial Printer Storage Location Terabyte (TB) Key Terms (cont’d.) Powered by DeSiaMore
Terminal Touch Screen Track Trackball Trackpad Trackpoint Unicode Video Display Terminal (VDT) Virtual Reality Volatile Storage Key Terms (cont’d.) Powered by DeSiaMore