Transcript Computer Merit Badge

Computer Merit Badge
History of Computers
History of Computers
Abacus
History of Computers
John Napier
Napier’s Bones
History of Computers
Herman Hollerith
Punched card
History of Computers
• University of
Pennsylvania Eniac
History of Computers
Dr. J. Presper & Dr. John Mauchly
UNIVAC
History of Computer
Vacuum Tubes
History of Computers
John Bardeen, Walter Brattain, and William Shockley:
Transistors
Types of Computers
Special Purpose
Watch
GPS
General Purpose
Office computer
Home computer
Types of Computers
Supercomputers
Cray
Mainframes
HP 8000, AS400
Minicomputers
obsolete
Microcomputers
Desktop, Laptop, PDA
Parts of a Computer
Central Processing Unit CPU
Input Device
Keyboard, Mouse, Scanner, Microphone
Storage Unit
Floppy Disk, Hard drive, Tape BU, CD
Output Device
Monitor, Printer, Modem, Network Card
Memory
• Ram – Random access memory is the
working area or scratch pad for the
computer measured in Megabytes.
• Rom – Read only memory is the
unchangeable instruction set that wakes
up the computer. Bootstrap, reboot, boot.
• Hard drive storage - Filing cabinet where
programs are stored till called into action.
Measured in Gigabytes.
Understanding Data
Binary number system
00001001 = 9
One digit is one bit
8 bits make a byte
Kilobyte is 210 or 1024 bytes
Megabyte
Gigabyte
Terabyte
ASCII
American Standard Code for Information
Interchange
A special code corresponding to the
numbers 0 through 255
Character ASCII Code Binary Number
$
36
00100100
Open Word and type Alt 36
Text files - .txt, .doc, .wp
Monitors
• Pixels are dots of red, green and blue
phosphor on the screen that glow when
struck by electrons.
• 24 bit true color will produce 16.7 million
different colors; the maximum the human
eye can see.
• Picture files - .mpg, .gif, .jpg, .pct
Sound
• Computers store sound by sampling the
sound wave at very fast intervals and
assigning values of pitch, tone, and
amplitude to the sample.
• Sound files - .au, .wav, mp3
Software
• Software is a set of instructions that tells
the hardware what to do.
• Operating systems – DOS, Windows 95,
98, ME, XP, Linux, Unix, Mac OS
• Applications – Word, Excel, Access,
Doom, Quake, Space Invaders
• Programming Languages – C++, Java,
HTML, FORTRAN, Pascal, COBOL, Basic
• Open Word – Alt F11 Visual Basic Editor
Applications
• Graphics – paint, CAD
• Computer Generated Animation – Shrek
• Sound programs – MIDI, Real Audio,
Windows Media Player
• Communications programs – Telnet, Hyper
Terminal, Remote Desktop, PC Anywhere,
emulators
Programming
• Programming languages convert
instructions humans understand (source
code) into binary machine code that the
computer understands (object code).
• Machine code cannot port to another
machine unless it is identical.
• A Compiler program is written for each
type of computer so programs can be
ported.
Communications Networks
• Modems – change digital to analog for
phone line use.
• DSL – Digital Subscriber Line
• Cable “Modem” – Router
• Satellite
• Wireless – 802.11, wifi, bluetooth, infrared
Computers at Work
Electrical engineer – design hardware
Programmers – write instruction code
Network engineer – design & run networks
Technicians – troubleshoot hardware and
assist users with software issues
Graphic designers – create commercial art
and film
Robotics – remote control of machines
Copyrights
• Books, movies, music, software and
pictures are copyrighted by the authors or
publishers. Copies cannot be created
without special permission or fee.
• Shareware – test drive for free, pay if you
keep it.
• Public Domain software – free to use and
copy. GNU, Freeware, Copyleft.