Early Computer History

1. Early Computer History How it all began

2. Pascalene 1624 The first accurate mechanical calculator Created by Blaise Pascal Used to add, subtract, multiply, and divide Early Computer History • Jacquard Loom 1820 • Created by Joseph Jacquard • A machine that automated the weaving of complex patterns • Used holes punched in cards to automate the process

3. Early Computer History • Hollerith Tabulating Machine 1890 • Created by Herman Hollerith • Used punch cards to tabulate census data • Hollerith started the Tabulating Machine Company, which later became IBM • Analytical Engine 1834 • Created by Charles Babbage • The father of computing • The first automatic calculator • Includes components similar to those found in today's computers

4. Early Computer History • Z1 1936 • Created by Konrad Zuse • The Z1 is a mechanical calculator • It included a control unit and memory functions • Atanasoff-Berry Computer 1939 • Created by John Atanasoff and Clifford Berry • The first electrically powered digital computer • Used vacuum tubes to store data • The first computer to use the binary system Atansoff-Berry Computer

5. Early Computer History • Harvard Mark I 1944 • Created by Howard Aiken and Grace Hopper • A computer used by the US Navy for ballistics calculations • Hopper’s contribution to computing was • Invention of the compiler • Coined the term “computer bug” • Turing Machine 1939 • Created by Alan Turing • A hypothetical model that defined a mechanical procedure or algorithm • Concept of an infinite tape that could read, write, and erase was precursor to today’s RAM 1st use of “computer bug”

6. Early Computer History • ENIAC 1944 • Created by John W. Mauchly and J. Presper Eckert • The first successful high-speed electronic digital computer • UNIVAC 1951 • The first commercially successful electronic digital computer • Used magnetic tape ENIAC UNIVAC

7. Early Computer History • Transistors 1945 • Invented at Bell Laboratories • Replaces vacuum tubes • Integrated circuits 1958 • Invented by Jack Kilby of Texas Instruments • A small chip containing thousands of transistors • Enabled computers to become smaller and lighter

8. Early Computer History • Microprocessor chip 1971 • Created by Intel Corporation • A small chip containing millions of transistors • It functions as the central processing unit (CPU)

9. Computer Generations • First-generation computers (1946–1958) • UNIVAC • Use vacuum tubes to store data • Second-generation computers (1959–1964) • Use transistors to store data • Third-generation computers (1965–1970) • Use integrated circuits • Fourth-generation computers (1971–Today) • Use a microprocessor chip

10. Intel 8080 and the Altair 8800 • The first microcomputer • Sold as a kit • Switches for input • Lights for output • Gates and Allen create a compiler for Basic • MITS receives 4,000 orders

11. Beginners All-Purpose Symbolic Instruction Code (BASIC) • Revolutionized the software industry • Programming language that beginners could easily learn • Key language of the PC • Bill Gates and Paul Allen used BASIC to write the program for the Altair • Led to the creation of Microsoft

12. Apple I and Apple II • Apple I built by Steve Wozniak in 1976 • Apple II developed by Steve Jobs in 1977 • Uses Motorola processor • First fully contained microcomputer • Highly successful

13. Early Competitors • Commodore • TRS-80 • Osborne

14. IBM PC • IBM enters small computer market 1981 • Uses open architecture • Purchases operating system from Microsoft

15. Graphical User Interface Xerox Alto • Xerox • Palo Alto Research Center • Alto: 1972 • Apple • Lisa: 1983 • Macintosh: 1984

16. The Internet Boom • Mosaic • Netscape • Internet Explorer • Windows 95

17. Computer Hardware Central Processing Unit & Random Access Memory

18. The CPU: Processing Digital Information • CPU is the brains of the computer • Different types of CPUs • Intel and AMD chips: Used in most Windows-based PCs • Apple systems use different CPU design • Differentiating CPUs • Processing power • Clock speed and cache

19. The Control Unit • Manages the switches inside the CPU • Is programmed by CPU designers to remember the sequence of processing stages for that CPU • Moves each switch to its correct setting (on or off) and then performs the work of that stage

20. The Arithmetic Logic Unit (ALU) • Part of the CPU designed to perform mathematical operations (addition, subtraction, multiplication, division, etc.) • Also performs logical OR, AND, and NOT operations • Is fed data from the CPU registers • Word size: Number of bits a computer can work with at a time

21. Registers • Small areas of storage in the CPU • Holds data and results of current operations • Holds current instruction • Holds address in memory of next instruction to execute

22. The CPU Machine Cycle • Fetch • The program’s binary code is “fetched” from its temporary location in RAM and moved to the CPU • Decode • The program’s binary code is decoded into commands the CPU understands. • Execute • The ALU performs the calculations. • Store • The results are stored in the registers

23. The System Clock • Located on the motherboard • Controls the CPU’s processing cycles • Clock cycle • Pulse or tick • Clock speed • Number of pulses per second • Measured in hertz (Hz)

24. Making Computers Faster • Dual processing • Two CPUs on the same system • Each processor shares the workload • Parallel processing • Network of computers • Each computer works on a portion of the problem simultaneously Dual processors

25. Making Computers Faster • Pipelining: The CPU processes more than one instruction at a time Non-pipelined CPU Instruction 1 Fetch Decode Execute Store Instruction 2 Fetch Decode Execute Store Pipelined CPU Instruction 1 Fetch Decode Execute Store Instruction 2 Fetch Decode Execute Store Instruction 3 Fetch Decode Execute Store Instruction 4 Fetch Decode Execute Store

26. Moore’s Law • Number of transistors on a CPU will double every 18 months • First chip had 29,000 transistors • Pentium chip 169,000,000 transistors • Moore’s Law has been accurate for 25 years

27. Cache Memory • Small amount of memory located on the CPU chip or near it • Stores recent or frequently used instructions and data • Used for quick access by the CPU • Different levels of cache

28. RAM: The Next Level of Temporary Storage • Volatile: When you turn off your computer, the data is erased • Several kinds of RAM exist • Each type of RAM has a different design • Some types work at much faster speeds • Some transfer data more quickly • Primary Storage

29. Memory Modules & RAM Memory modules: • SIMM • DIMM • Types of RAM: • SRAM • DRAM • SDRAM

30. Types of RAM: DRAM • Dynamic RAM (DRAM) • Cheapest and most basic type of RAM • Loses its electrical charge • Needs to be refreshed • Many types of DRAM • SDRAM: Synchronous DRAM • DDR SDRAM: Double data rate SDRAM

31. Types of RAM: SRAM • Static RAM (SRAM) • Does not lose its electrical charge • Faster than DRAM • More expensive than DRAM • Used only in locations like cache memory

32. More Memory Types • Read Only Memory - ROM • Complementary Metal-oxide Semiconductor - CMOS • Video Ram

33. Buses: The CPU’s Data Highway • Bus • Electrical pathway used to move data between components • Local bus: Connects the CPU with the memory • Expansion bus: Connects the CPU with peripheral devices 01100010 01001000 01110011 00100111

34. Bus Performance • Bus clock speed • Rate of speed data moves from one location to another • Measured in Mhz (millions of clock cycles per second) • Bus width • The number of bits of data moved on a bus at any one time • Measured in bits • 16 bits • 32 bits