TK 2123 COMPUTER ORGANISATION & ARCHITECTURE Lecture 3: Computer Evolution

Contents This lecture will discuss: A Brief History of the Computer. Moore’s Law Prepared by: Dr Masri Ayob - TK2123

A Brief History of the Computer It is not possible, nor particularly useful, to identify the date of the “invention” of the computer. Indeed it has always been the aspiration of humankind to create devices that would simplify people’s work. E.g. one could consider the abacus, already in use as early as 500 B.C. by the ancient Greeks and Romans, to be an early predecessor of the computer. Prepared by: Dr Masri Ayob - TK2123

Mechanical Computers (1642 – 1945) Charles Babbage, an English mathematician who lived in the early 1800s, build a mechanical calculating machine that he called an “analytical engine.” The analytical engine (Babbage’s machine) resembles the modern computer in many conceptual ways. Prepared by: Dr Masri Ayob - TK2123

Babbage’s machine Babbage’s machine: use punched cards for input data and for the program; provided memory for internal storage; performed calculations as specified by the program using a central processing unit known as a “mill,” and printed output. The sequence of operation was specified by instructions on the operation cards. The operation cards could be advanced or reversed as a means of implementing a sort of “goto” instruction. The second set of cards, known as variable cards, were to be used to specify particular memory locations for the data involved in the calculations. Prepared by: Dr Masri Ayob - TK2123

Figure 1.12 Block diagram of Babbage’s analytical engine Source: From Computer Architecture and Organization 2e, J. Hayes, copyright © 1988, by McGraw-Hill Companies, pg. 14 Reprinted by permission. Prepared by: Dr Masri Ayob - TK2123

Babbage’s machine Although the analytical engine was never completed, it should be apparent to you that it contains all the essential elements of today’s computers. Prepared by: Dr Masri Ayob - TK2123

Boolean Logic At approximately the same time, George Boole (English mathematician), developed the binary theory of logic- Boolean logic. He also recognized the relationship between binary arithmetic and Boolean logic that makes possible the circuitry that implements the modern electronic computer. Prepared by: Dr Masri Ayob - TK2123

ENIAC background Much of the effort that culminated in a successful general-purpose computer architecture resulted from a wartime need for the solution to difficult mathematical formulas related to ballistic missile trajectories and other World War II research. Electronic Numerical Integrator And Computer (ENIAC) is generally considered to be the first all-electronic digital computer Prepared by: Dr Masri Ayob - TK2123

ENIAC - background Eckert and Mauchly University of Pennsylvania Trajectory tables for weapons Started 1943 Finished 1946 Too late for war effort Used until 1955 Prepared by: Dr Masri Ayob - TK2123

ENIAC - details Decimal (not binary) 20 accumulators of 10 digits Programmed manually by switches 18,000 vacuum tubes 30 tons 15,000 square feet 140 kW power consumption 5,000 additions per second Prepared by: Dr Masri Ayob - TK2123

von Neumann In 1945, John von Neumann, a consultant on the ENIAC project, proposed a computer that included a number of significant improvements over the ENIAC design. Stored Program concept. Prepared by: Dr Masri Ayob - TK2123

von Neumann Main memory storing programs and data ALU operating on binary data Control unit interpreting instructions from memory and executing Input and output equipment operated by control unit. Two different version of von Neumann’s architecture were designed and built: IAS at the Princeton Institute for Advanced Studies. EDVAC at the University of Pennsylvania. Completed 1952. Prepared by: Dr Masri Ayob - TK2123

The original Von Neumann machine. Prepared by: Dr Masri Ayob - TK2123

IAS - details 1000 x 40 bit words Set of registers (storage in CPU) Binary number 2 x 20 bit instructions Set of registers (storage in CPU) Memory Buffer Register Memory Address Register Instruction Register Instruction Buffer Register Program Counter Accumulator Multiplier Quotient Prepared by: Dr Masri Ayob - TK2123

Structure of IAS – detail Prepared by: Dr Masri Ayob - TK2123

Transistors Replaced vacuum tubes Smaller Cheaper Less heat dissipation Solid State device Made from Silicon (Sand) Invented 1947 at Bell Labs William Shockley et al. Prepared by: Dr Masri Ayob - TK2123

Transistor Based Computers Second generation machines NCR & RCA produced small transistor machines IBM 7000 DEC - 1957 Produced PDP-1 Prepared by: Dr Masri Ayob - TK2123

Microelectronics Literally - “small electronics” A computer is made up of gates, memory cells and interconnections These can be manufactured on a semiconductor e.g. silicon wafer Prepared by: Dr Masri Ayob - TK2123

Generations of Computer Zeroth Generation :Mechanical Computers (1642 – 1945). Vacuum tube: 1946-1957 Transistor: 1958-1964 Small scale integration: 1965 on Up to 100 devices on a chip Medium scale integration:- to 1971 100-3,000 devices on a chip Large scale integration: 1971-1977 3,000 - 100,000 devices on a chip Very large scale integration: 1978 -1991 100,000 - 100,000,000 devices on a chip Ultra large scale integration: 1991 - Over 100,000,000 devices on a chip Prepared by: Dr Masri Ayob - TK2123

Moore’s Law Increased density of components on chip Gordon Moore – co-founder of Intel Number of transistors on a chip will double every year Since 1970’s development has slowed a little Number of transistors doubles every 18 months Cost of a chip has remained almost unchanged Higher packing density means shorter electrical paths, giving higher performance Smaller size gives increased flexibility Reduced power and cooling requirements Fewer interconnections increases reliability Prepared by: Dr Masri Ayob - TK2123

Growth in CPU Transistor Count Prepared by: Dr Masri Ayob - TK2123

IBM 360 series 1964 Replaced (& not compatible with) 7000 series First planned “family” of computers Similar or identical instruction sets Similar or identical O/S Increasing speed Increasing number of I/O ports (i.e. more terminals) Increased memory size Increased cost Multiplexed switch structure Prepared by: Dr Masri Ayob - TK2123

DEC PDP-8 1964 First minicomputer Did not need air conditioned room Small enough to sit on a lab bench $16,000 $100k+ for IBM 360 Embedded applications BUS STRUCTURE Prepared by: Dr Masri Ayob - TK2123

Intel 1971: 4004 First microprocessor All CPU components on a single chip 4 bit Followed in 1972 by 8008 8 bit Both designed for specific applications 1974: 8080 Intel’s first general purpose microprocessor Prepared by: Dr Masri Ayob - TK2123

Thank you Q & A Prepared by: Dr Masri Ayob - TK2123