About Computers

Definition of a Computer
Simplest definition of a computer: A device that processes input and generates output
Key words:

• Input
• Output
• Processes
• Information

Modern Computers are electronic, complex, and interactive, but can be reduced to simple input-output processing devices

History of Computers: 3000 BC to Present History of Computers - Long, Long Ago The Abacus beads on rods to count and calculate still widely used in Asia!

History of Computers - Way Back When The Slide Rule 1630 based on Napier’s rules for logarithms used until 1970s

 

History of Computers - 19th Century Jacquard Loom used metal cards with punched holes to guide weaving process first stored program - metal cards first computer manufacturing still in use today!

 
 

Charles Babbage - 1792-1871 Difference Engine c.1822 huge calculator, never finished Analytical Engine 1833 could store numbers calculating "mill" used punched metal cards for instructions powered by steam! accurate to six decimal places

Ada Augusta - First Programmer

• Worked with Charles Babbage
• Programmed Analytical Engine

Discussion Question

• What was the biggest advance that led to modern computers?
• Electricity
• Transistor
• Microchip
• Data storage

Vacuum Tubes - 1930 - 1950s First Generation Electronic Computers used Vacuum Tubes Vacuum tubes are glass tubes with circuits inside. Vacuum tubes have no air inside of them, which protects the circuitry.
UNIVAC - 1951 First commercially available computer sold to censu bureau "a big pocket calculator" until 1970 was standard computer, but very expensive http://www.letsfindout.com/subjects/space/univac.html
Grace Hopper	Programmed UNIVAC Recipient of Computer Science’s first "Man of the Year Award" http://www.ce.vt.edu/evd/Htmls/P375994.html
First Computer Bug - 1945 Relay cards carried information Grace Hopper found an actual moth stuck to card responsible for a malfunction Called it "debugging" a computer
First Transistor Uses Silicon developed in 1948 won a Nobel prize on-off switch Second Generation Computers used Transistors, starting in 1956

Integrated Circuits Third Generation Computers used Integrated Circuits (chips). Integrated Circuits are transistors, resistors, and capacitors integrated together into a single “chip”

Birth of Personal Computers - Kenbak I - 1971 Very primitive, just flashing lights and buttons about $750 MITS Altair - 1975 (pictured) 256 byte memory 2 MHz Intel 8080 chips Just a box with flashing lights cost $395 kit, $495 assembled.

The First Microprocessor - 1971

• The Intel 4004 had 2,250 transistors
• four-bit chunks (four 1’s or 0’s)
• 108Khz
• 0.6 Mips (million instructions/sec)
• Pentium 133 - 300 Mips
• Called "Microchip"

Inside the Intel 4004 Microchip - 2250 Transistors 
 
 
Generations of Electronic Computers

Generation	FirstGeneration I	Second Gen.II	Third Gen.III	Fourth Gen.IV
Technology	Vacuum Tubes	Transistors	Integrated Circuits (multiple transistors)	Microchips (millions of transistors)
Size	Filled Whole Buildings	Filled half a room	Smaller	Tiny - Palm Pilot is as powerful as old building sized computer

 

Over the past 50 years, the Electronic Computer has evolved rapidly.

• Using the following advancements, draw an "evolutionary chart" of how computers evolved:
• vacuum tube
• integrated circuit
• transistor
• microchip

IBM PC - 1981

• IBM-Intel-Microsoft joint venture
• First wide-selling personal computer used in business
• 8088 Microchip - 29,000 transistors
• 4.77 Mhz processing speed
• 256 K RAM (Random Access Memory) standard
• One or two floppy disk drives

Apple Computers

• Founded 1977
• Apple II released 1977  - widely used in schools
• Macintosh (left) - released in 1984, Motorola 68000 Microchip processor (below)
• Macintosh is first commercial computer with graphical user interface (GUI) and pointing device (mouse)

1990s: Pentiums and Power Macs

• Early 1990s began penetration of computers into every niche: every desk, most homes, etc.
• Faster, less expensive computers paved way for this
• Windows 95 was first decent GUI for "PCs"
• Macs became more PC compatible - easy file transfers
• Prices have plummeted

   
How Electronic Computers Have Progressed
 

	UNIVAC(1951-1970) (1968 vers.)	Kenbak 1(1971)	IBM PC(1981)	Macintosh(1984)	Pentium III
Circuits	Tubes,Transistors, Integrated Circuits*	130 Integrated Circuits	Intel 8088Microchip - 29,000 Transistors	Motorola 68000	Intel P-IIIMicrochip - 7.5 million transistors
Generation	I-II-III*	III	IV	IV	IV
RAM Memory	512 K	265 Bytes	256 K	640 K	128 Mb
Speed	1.3 MHz	1 KHz	4.77 Mhz	8 MHz	1000 MHz
Storage	100 MB Hard Drive	none	Floppy Drive	Floppy Drives	Hard Drive, Floppy, CD-Rom
Size	Whole Room	Briefcase(no monitor)	Briefcase + Monitor	Two shoeboxes (integrated monitor)	Small Tower
Cost	$1.6 million	$750	$1595	~$4000	$1500

*Early UNIVACs had vacuum tubes, middle models had transistors, and by the end they used integrated circuits

What’s next for computers?

• Use your imagination to come up with what the next century holds for computers.
• What can we expect in two years?
• What can we expect in twenty years?