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Introduction to Computers
Charles Babbage
• “Father of the Computer”
• Created the first concept of a programmable
computer in 1822
• His machines were designed to contain tens of
thousands of precision-made gears
• He never actually built any of his designs
The Difference Engine
• In 1991, Babbage’s difference engine
was built
• If it had been completed, the
difference engine would have had
25,000 parts and weighed 15 tons
Herman Hollerith
• Designed a punch card system to calculate the
1880 census
• Reduced a ten year job to three months
• Saved the government $5 million
• Founded the company that became IBM
George Stibitz
• “Father of the Modern Digital
Computer”
• Discovered the use of relays for
automated computing in 1937
Alan Turing
• “Father of Computer Science”
• Invented the Turing machine in 1936
• Turing machine can be considered a
model of a general purpose computer
Grace Hopper
• Programmed the Mark I
Computer during WWII
• Led the team that created the
first computer language compiler
• Popularized the term “computer
bug” when a moth was found
inside the Mark II computer
History Continued
• Vacuum Tubes
•
An electron tube containing a near-vacuum that allows the free passage of electric
current
• Transistors
•
A semiconductor device used to switch electronic signals
• Integrated Circuit
•
An electronic circuit formed on a small piece of semiconducting material
Modern Computers
Hardware and Software
• Hardware
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•
Electric, electronic, and mechanical components
The machines, wiring, and other physical components of a computer
• Software
•
•
The programs and other operating information used by a computer
Software tells the computer what tasks to perform and how to perform them
The Components of a Computer
• Input – Allows users to enter data or instructions into a computer
• Output – Hardware that conveys information
• System Unit – Case that contains the electronic components
• Storage Device – Device that holds data, information, and instructions
• Communication Device – Enables a computer to send and receive data,
instructions, and information to and from one or more computers or mobile
devices
Input
• An input device is a piece of computer hardware equipment used to provide
data and control signals to the processing system of the computer
• Examples of input devices include keyboards, mouses, scanners, digital
cameras, and joysticks
Output
• An output device is any device that receives data from a computer, usually
for display, projection, or physical reproduction
• Examples of output devices are monitors and printers
Storage Device
• In this class, we will define a storage device as anything that connects to a
computer for the purpose of storing data
• Examples of storage devices are USB drives, CD/DVD drives, hard disk
drives, and card reader/writers
System Unit
• A system unit is what holds the components of a computer
• This is also commonly known as a tower, or simply referred to as a desktop
computer
The Components of a Computer
Image borrowed from http://biobio.loc.edu/chu/web/Courses/COSI118/lecture/hardware.htm
Ports on a Computer
• A port is a physical docking point to which an external device can be
connected
•
•
•
External devices are connected to a computer using cables and ports
Ports are slots on the motherboard where a cable can be plugged in
Examples of external devices attached via ports are mouses, keyboards, monitors,
microphones, speakers, etc.
Inside a Computer
• Motherboard – the computer’s main circuit board, a thin plate that holds the
CPU, memory, connectors for the hard drive and expansion cards, and
connections to the computer’s ports
• CPU/processor – the central processing unit, sometimes called the brain of
the computer
• RAM (random access memory) – short term memory, which temporarily
stores data until needed
• Hard drive – long term storage, where data is saved even when the
computer is turned off
• Power supply unit – converts the power from the wall outlet to the type of
power needed by the computer
Types of Computers
• Personal Computers
• Mobile Computers and Mobile Devices
• Game Consoles
• Servers
• Mainframes
• Supercomputers
• Embedded Computers
Personal Computer
• A computer designed for use by one person at a time
Mobile Computers and Mobile Devices
• A portable computing device such as a smartphone, tablet, or laptop
Game Consoles
• A specialized desktop computer used to play video games
Servers
• A computer or computer program that manages access to a centralized
resource or service in a network
Mainframe
• A large, high-speed computer, especially one supporting numerous
workstations or peripherals
Supercomputer
• A computer with a high-level computational capacity compared to a
general-purpose computer
Embedded Computer
• A special purpose computer that functions as a component of a larger
product
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Calculators
ATMs
Thermostats
Cameras
Printers
Operating Systems
• The operating system is software that supports a computer’s basic
functions, such as scheduling tasks, executing applications, and controlling
input/output
• The operating system manages the application that are installed on the
computer
• Examples of operating systems are Windows, Mac OS X, and Linux
Applications
• An application is a computer program designed to perform a group of
coordinated functions, tasks or activities for the benefit of the user
• Examples of applications include Google Chrome, Microsoft Word, and
Adobe Photoshop (these are just a few – there are many more)
Links for Further Study
• http://www.gcflearnfree.org/computerbasics/