The History of the Computer Then & Now

Computer Evolution 1642 Blaise Pascal – mechanical adding machine

Early 1800’s Jacquard – uses punch cards to control the pattern of the weaving loom 1832 Charles Babbage - invents the Difference Engine

The Punch Card 1890 Herman Hollerith – invents a machine using punch card to tabulate info for the Census. He starts the company that would later be IBM.

Evolution (continued) 1946 – Mauchly and Eckert created the ENIAC computer, first electronic computer is unveiled at University of Pennsylvania (shown on next slide)

ENIAC Computer Miles of wiring Miles of wiring 18,000 vacuum tubes 18,000 vacuum tubes Thousands of resistors and switches Thousands of resistors and switches No monitor No monitor 3,000 blinking lights 3,000 blinking lights Cost $486,000 Cost $486, ,000 additions per second 100,000 additions per second Weighed 30 tons Weighed 30 tons Filled a 30x50 foot room Filled a 30x50 foot room Lights of Philadelphia would dim when it booted up Lights of Philadelphia would dim when it booted up

1943 Base codes develop by Grace Hopper while working on the Mark I programming project. She invented the phrase “bug” – an error in a program that causes a program to malfunction.

1950s Vacuum Tubes were the components for the electronic circuitry Punch Cards main source of input Speeds in milliseconds (thousands/sec) 100,000 additions/sec. Used for scientific calculations New computers were the rule, cost effectiveness wasn’t

Transistors were electronic circuitry (smaller, faster, more reliable than vacuum tubes) Speeds in microseconds (millionth/sec) 200,000 additions/sec. Computers In Businesses: Emphasis on marketing of computers to businesses Data files stored on magnetic tape Computer Scientists controlled operations 1960s

Late 60’s Early 70’s Integrated circuit boards New input methods such as plotters, scanners Software became more important Sophisticated operating systems Improved programming languages Storage capabilities expanded (disks)

1970’s Integrated circuits and silicone chips lead to smaller microprocessors

Late 80’s to Current Improved circuitry – several thousand transistors placed on a tiny silicon chip. Pentium chip named by Intel Modems – communication along telephone wires Portable computers: laptops Increased storage capabilities: gigabytes Emphasis on information needed by the decision maker.

The Information Processing Cycle INPUT OUTPUT AUXILIARYSTORAGE PROCESSING MAINMEMORY

What is Data? Facts used by a computer –WORDS –NUMBERS

INPUT DEVICES (Hardware) Keyboard Mouse Joystick Trackball Light pen Image scanner Touch tone telephone Touch screens Bar code scanner Digitizer Voice recognition Auxiliary Storage Device INPUT

Central Processing Unit: CPU The Brains or Intelligence of the computer. Controls input and output The part of the computer that interprets and executes instructions. Silicon chip: integrated circuit board Pentium: name give to a particular chip PROCESSING PROCESSING HARDWARE

Processors Come in Many Sizes Mainframe Mainframe: large, powerful, serving many connected terminals. Super Computers Minicomputer Minicomputer: mid-sized, serves more than one user at a time Microcomputer Microcomputer: PC, individual workstation Laptop:portable, small Laptop:portable, small Handheld Handheld: Palm Pilots

What two numbers are used in Binary Code? 0 and 1 They are each called a BIT 8 BITS make a BYTE 1 BYTE makes a letter or number KILOBYTE = 1,024 bytes MEGABYTE = 1,048,576 bytes GIGABYTE = 1,024 megabytes TERABYTE = 1,024 gigabytes

MEMORY PROCESSING HARDWARE MEMORY PROCESSING HARDWARE ROM R EAD O NLY M EMORY Small Instructions are installed permanently at the factory Cannot be changed These instructions check the computer’s resources and looks for Operating SystemRAM ANDOM CCESS EMORY R ANDOM A CCESS M EMORY Main Memory Temporary—it is erased when turned off. It is where programs and data is stored while being processed MEMORY

OUTPUT DEVICES ( HARDWARE) Useful information that leaves the system Output Hardware includes: Monitor: soft copy Printers: hard copy Flat Panel displays Voice and music - speakers Synthesizers Plotters OUTPUT

AUXILIARY STORAGE DEVICES Network Drive ( H: drive) Hard Disk Drive ( C:drive) Floppy Disk Drive with 3 ½” Floppy Disk ( A:drive) Smart card CD Read/Write Drive Zip Drive Digital Audio Tape AUXILIARYSTORAGE

SOFTWARE Operating System Software Windows 98: GUI (Graphical User Interface) Windows XP: GUI (Graphical User Interface) Unix Application Software Microsoft Word, Excel, Access, Front Page, Publisher WordPerfect Pagemaker, Photoshop, Dreamweaver Programs that Make the Computer Work

What is the Boot Process? The process of starting up a computer from a halted or powered-down condition. Commands in ROM memory are followed The process of loading the Operating System software into Main Memory Windows 98 Windows XP Unix What boots up must come down

The Information Processing Cycle INPUT OUTPUT AUXILIARYSTORAGE PROCESSING MAINMEMORY