• The timeline of computers started a thousand yeas ago, with the abacus.
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Abacus allows users to perform computations quickly by sliding beads arranged on racks.
• 1642, Blaine Pascal invented a numerical wheel calculator.
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1812, Charles Babbage recognized the harmony between mathematics and machines.
• The Analytical Engine was designed to make conditional decisions.
• Babbage’s design outlined the main components of today’s multipurpose computers.
• 1820, Charles Xavier Thomas de Colmar invented the arithometer.
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With various improvements this device remained in widespread until World War 1.
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Herman Hollerith invented a machine where data was stored and a machine compiled results.
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This invention reduced the time of counting census from 10 years to 6 weeks
• After this Hollerith made a company named International Business Machines (IBM).

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In England, the Colossus was constructed to decode encrypted German Messages.
 U.S. Army Ordnance and University of Pennsylvania together made the ENIAC.
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ENIAC took 3 years to build, weighs over 30 tons, contains 19,000 tubes, 1,500 relays, and consumes about 200 kilowatts of power.
 ENIAC could perform complex calculations faster than anything else in existence.
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ENIAC calculated 1 min equations in 30 seconds, which would of took a skilled human being 20 hours.
 ENIAC got wiped out by more powerful computers invented after a while such as the EDVAC and UNIVAC.

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1956, computers went from large and bulky to transistors.
 Transistors use electrical charge to change conductive properties of transistor allowing it to alternate between insulator and conductor.
 Conductor means it’s in an “on” state and insulator means it’s in an “off ” state.
 Supercomputers wee used by atomic energy.
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Same time advances in printers, tape storage, and memory made computers multifunctional.
 Machine language a binary system of 1s and 0s communicates instructions to computers hardware.
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An assembly language uses human code (e.g. MOV or STORE to represent 1s and 0s.
 Scientists developed high-level languages like COBOL used for business use.
 Scientists also developed FORTRAN for scientific research.

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Integrated circuit (IC) was invented by Jack Kilby and Robert Noyce.
 ICs produced less heat than transistors.
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Less heat allowed more components on a chip.
 A chip is a semiconducting substance that is as thin as a wafer.
 Tiny electronic pathways are etched on the surface.
 These “microchips” revolutionized computers by shrinking from a size of a room to a size of a laptop.
 Now computers are smaller and more reliable.

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With integrated chips, small chips, and smaller computers more businesses bought them.
 First affordable computer, MITS (PC) in 1974.
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After came Apple 1&2, and the Commodore PET.
 1981 IBM release first PC.
 Original IBM PC leaded to a widespread in computer use.
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By 1990 65 million PCs were in use.
 After 20 years since first PC released, about 1 billion computers used worldwide.
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Both computer hardware and software was rapidly evolving.
 UNIX and WINDOWS are very complicated software's compared to 1930s.
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Without computers in todays society, that will be extremely difficult.

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Hardware is physical components of computer.
 Input devices allow you to enter information and computer does the rest.
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Keyboard and mouse most used for inputting devices.
 Other input devices, scanners, digitizing pads, etc.
 Another example is voice command in computers.
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All these devices tell computer what to do.
 Output tells us what the computers doing.
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Old computers use banks of lights for output.
 Most common output device is monitor.
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This is hooked to computer card and creates a picture onscreen.
 Printers facilitate information from computer to paper.

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Central processing unit most important component for computer.
 CPU brains of computer.
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Capable of performing millions of basic functions in one second.
 Any information in CPU gets broken down into millions of tiny transistors.
 CPU alone has no memory.
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Random-access memory (RAM) is where info from CPU goes.
 RAM isn’t a long term solution.
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When computer turns off then all info on RAM is deleted.

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Long term storage of data could be hard drives, CD-ROMs,etc.
 Storage capacity is how many bits of data medium can store.
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On and Off states represented by Binary digiTS (BITS).
 Eight bits is called a byte.
 Primary storage device in computer is the hard drive.
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Hard drive store data on magnetic platters made of aluminum or glass.
 Laptop hold 60 gigabytes or more.
 Hard drives aren’t portable.
 Floppy disk are now being placed by more capable storage types.

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Networking is most explosive growth area in computer industry.
 Since its feasible to connect computers everyone has a network.
 Only some small businesses don’t have a network.
 In networking media are the physical connections.
 When media connect network to computers it’s called nodes.
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Each node has network face card which allows data back and forth.
 Layout of network is called topology.
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Nodes can also be connected to a server.
 Server holds data that everyone on the server can use.

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Operating systems manage the hard ware and software.\
 CPU performs one operation at a time, and the system can old only so much info.
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Operating system manages applications from software to hardware.
 User interacts with computer through interface.
 API helps programmers create applications that function consistently.
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Operating systems fall into several categories, familiar is one user.
 User can tap resources of one computer to perform multiple tasks.
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Windows and Mac0S are examples of these systems.
 Multiuser operating systems allow multiple users to tap resources on a single computer.

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Desktop software runs on little hardware and has to be installed into computer for use.
 This idea is changing as more people are connecting to internet.
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Modern software divides tasks performed on desktop and data received.
 Desktop software is categorized by the function it serves.
 For instance there are so many applications on a computer.
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Each category may also have divisions in it.
 Within utility category one might find antivirus utilities, disk utilities,etc.