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- Media Technologies: Computers
- Computers
- Hardware
- Monitor
- Motherboard
- CPU
- RAM
- Expansion cards
- Power supply
- Optical disc drive
- Hard disk drive
- Keyboard
- Mouse
- Input
- Software
- instructions for the hardware
- Output
- Mechanical Computers
- gears and levers
- adding machines, calculators, and machines
- Stepped Reckoner (1672)
- Difference Engine (1822)
- Jacquard Loom (1801)
- Analytical Engine (1837)
- Analytical Engine
- Charles Babbage, 1837
- grind out calculations in a mill
- input/output: punch cards
- never completed
- Bit
- Binary Digit
- logical values
- only thing computers actually process
- Byte
- combination of bits
- hexadecimal: 4-bits
- most text: 7–8 bits
- Byte
- basic computer unit
- a letter of text
- example, American Standard Code for Information Interchange
- Bits and Bytes
- 1-bit = 21 = 2 byte combinations
- 2-bit = 22 = 4 byte combinations
- 3-bit = 23 = 8 byte combinations
- 4-bit = 24 = 16 byte combinations
- 5-bit = 25 = 32 byte combinations
- 6-bit = 26 = 64 byte combinations
- 7-bit = 27 = 128 byte combinations
- 8-bit = 28 = 256 byte combinations
- Like Morse Code
- Storage
- storing bits
- record (write)
- retrieve (read)
- Punch Card
- paper card
- sequential
- each hole represents a bit, e.g. “on”
- each “non-hole” represents a different bit, e.g. “off”
- Magnetic Storage
- Each bit is “written” on a magnetically-charged metal particle
- read back and loaded to the computer
- non-volatile
- magnetic tape
- floppy disk
- hard disk
- magnetic tape
- floppy disk
- first hard disk drive
- IBM, 1956
- size: a car
- storage: 3.75 megabytes
- cost: $30,000
- hard disk
- size: about 2.5 – 3.5 inches
- storage: 4 terabytes
- cost: $150
- disk spins between 5400 and 7200 rpm
- magnetic head is about 10 nm from disk surface
- Optical Storage
- binary data store on a metal disk
- encased in plastic
- read/written by laser light or electromagnetic waves
- CD: Compact Disks (red laser)
- DVD: Digital Versatile Disk (white laser)
- Blu-ray (blue laser)
- Processors
- process and calculate numbers
- faster than human counting
- faster than mechanical computers
- Diodes
- vacuum tubes
- Thomas Edison’s lightbulb, 1883
- John’s Fleming valve, 1904
- Lee deForest’s audion,
- ENIAC
- first electronic computer, 1946
- “Giant Brain”
- Electronic Numerical Integrator And Calculator
- processed calculations for the hydrogen bomb
- Colossus
- British, 1943–1945
- World War II
- crack Nazi codes
- Lorenz cipher
- non-Morse code transmissions
- Big Computers for Big Guys
- governments
- military
- university research
- World War II: to save the world
- “Personal” Computer, 1954
- Transistor
- Bell Labs, 1947
- semiconductor
- telephone circuits
- transistor radios
- electronic computers
- Minicomputers
- powered by transistors
- mid 1960s
- smaller than “mainframe” computers
- cabinet-sized
- cost about $25,000
- Minicomputers for Corporations
- banking records
- university enrollments
- airline reservations
- hotel bookings
- Microprocessors
- Intel, 1971
- silicon switches
- Moore’s law
- every two years…
- double the number of transistors…
- in the same circuit.
- Microcomputers
- powered by microprocessors
- emerged 1970s
- small central processing unit (CPU)
- desktop and tabletop sized
- Personal Computer
- microcomputers powered by microprocessors
- emerged in 1970s and 1980s
- desktop sized
- keyboard, display, magnetic storage
- Altair 8800
- microcomputer kit, 1975
- Intel 8800 microprocessor
- 256 bytes of RAM, no storage
- front panel with lights
- mail order, $400–$500
- first personal computer
- Apple I
- Steve Jobs and Steve Wozniak, 1976
- demonstrated at Homebrew Computer Club
- fully assembled circuit board
- sold for $666.66
- Xerox Alto
- Xerox Palo Alto Research Center, 1973
- GUI: graphical user interface
- desktop metaphor
- tens of thousands dollars
- sparked the GUI computer of the 1980s
- Macintosh
- Apple, 1984
- desktop metaphor
- graphical user interface
- 128 kilobytes of RAM
- no storage
- IBM PC Jr
- Handhelds
- Wearables
- smart watches
- shirt
- glasses
- wristwatch
- wristbands
- trousers
- hand
- shoes
- Digital Media
- modern Media: daguerrotype
- computable data: analytical engine