Computer Merit Badge History of Computers

Abacus

History of Computers John Napier Napier’s Bones

History of Computers Herman Hollerith Punched card

History of Computers University of PennsylvaniaEniac

History of Computers Dr. J. Presper & Dr. John MauchlyUNIVAC

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 UnitCPU 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 = 9 One digit is one bit 8 bits make a byte Kilobyte is 2 10 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 CodeBinary Number $ 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 – , 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.