1. CSCI-100 Introduction to Computing
Computer History

2. Gross Anatomy Hardware: equipment associated with the computer
Input devices, processor, output devices, storage
Software: instructions that tell the hardware what to do
Two categories of software:
System software
Application software

3. Application (ex: browser)
Coordination of many levels (layers) of abstraction
Application (ex: browser)
Operating
System
(ex: Mac OSX)
Software
Instruction Set
Architecture
Hardware
Processor
Memory
I/O system
Digital Design
Circuit Design
transistors

4. Instruction Set Architecture
Basic job of a CPU: execute lots of instructions
Instructions are the primitive operations that the CPU
may execute
Different CPUs implement different sets of instructions
The set of instructions a particular CPU implements is
an Instruction Set Architecture (ISA)
Examples: Intel 80x86 (Pentium 4), IBM/Motorola PowerPC (Macintosh), MIPS, Intel IA64, ...

5. instruction set
software
hardware

6. von Neumann Architecture
Although specific components may vary, virtually all modern computers have the same underlying structure
known as the von Neumann architecture
Named after computer pioneer, John von Neumann, who popularized the design in the early 1950's

7. The von Neumann architecture identifies 3 essential components:
Input/Output Devices (I/O) allow the user to interact with the computer
Memory stores information to be processed as well as programs (instructions specifying the steps necessary to complete specific tasks)
Central Processing Unit (CPU) carries out the instructions to process information

8. First “computer”?
The first actual calculating mechanism known to us is the abacus, which was invented about 2000 years ago
Video

9. Many references cite the French mathematician, physicist, and theologian Blaise Pascal as being the inventor of the first mechanical calculator in 1642, the Arithmetic Machine

10. However, it now appears that the first mechanical calculator may have been conceived by someone else almost 150 years earlier than Pascal's machine. Can you guess who?
Leonardo Da Vinci

11. In the early 1800s, a French silk weaver called Joseph-Marie Jacquard invented a way of automatically controlling the warp and weft threads on a silk loom by recording patterns of holes in a string of cards

12. The first device that might be considered to be a computer in the modern sense of the word was the Difference Engine to automatically calculate mathematical tables conceived in 1822 by the British mathematician and inventor Charles Babbage
The Difference Engine was only partially completed when Babbage conceived the idea of another, more sophisticated machine called the Analytical Engine
The Analytical Engine was intended to use loops of Jacquard's punched cards to control an automatic calculator, which could make decisions based on the results of previous computations
Video

13. Working with Babbage was Augusta Ada Lovelace, the daughter of the English poet Lord Byron. Ada, who was a splendid mathematician and one of the few people who fully understood Babbage's vision, created a program for the Analytical Engine
Ada is now credited as being the first computer programmer and, in 1979, a modern programming language was named ADA in her honor

14. In 1939, a German engineer, Konrad Zuse built the first programmable, general-purpose digital computer. His computer was built from electric relays to automate engineering calculations
“I was too lazy to calculate and so I invented
the computer.”
John Atanasoff invented the Atanasoff-Berry Computer (ABC) —the first electronic digital computer. Built in 1939, this computer used vacuum tubes and was based on binary arithmetic. It was never a fully operational product

15. In 1944, Howard Aiken completed the Mark I, the largest electromechanical calculator ever built. It was built with electromechanical relays and followed instructions punched in paper tape

16. The first computer “bug”

17. In 1945, Mauchly and Eckert built the ENIAC (Electronic Numerical Integrator and Computer). The ENIAC was built with 18,000 vacuum tubes that failed on an average of once every seven minutes
After the war, they created the UNIVAC I - the first general-purpose commercial computer

18. First-Generation Computers
1930s – 1940s
Vacuum tubes used as switches
Large computers
Extremely slow by today’s standards
Prone to frequent failure
Includes the ABC, Mark I, ENIAC, UNIVAC, and others of similar design

19. Second-Generation Computers
1950s – mid-1960s
Transistors used as switches
Smaller than vacuum-tube-built computers
As much as a thousand times faster than first-generation computers
More reliable and less expensive

20. Third-Generation Computers
Late 1960s
Hundreds of transistors packed into a single integrated circuit on a silicon chip
Dramatic reduction in size and cost
Significant increases in reliability, speed, and efficiency
Mass production techniques to manufacture chips inexpensively

21. Fourth-Generation Computers
1970s to present
Complete computer on a chip
Radical change in the appearance, capability and availability of computers

22. Gordon Moore Intel Cofounder # of transistors on an IC
Technology Trends: Microprocessor Complexity
Gordon Moore Intel Cofounder
# of transistors on an IC
2X Transistors / Chip
Every 1.5 years
Called “Moore’s Law”
Year