1. Binary Representation of Information bit: 0 byte: 0110 11000 "word": 01011100 11101111 00010000 11110000 chapter 8

2. Slide 8-2 Digital Information (Binary) There are 10 different kinds of people in the world: those who know binary and those who don't. --Anon

3. Slide 8-3 Digital Information (Binary) Von Neumann Architecture A. CPU; B. RAM; C. I/O; D. Bus What Can Computers Do? 1. I/O operations 2. Storage ops. (RAM, disk, disc,...) 3. Arithmetic ops. (+, -, *, /, %, ^,...) 4. Logic ops. ( =, >, AND, OR,...) ==> Computers are technologically complex but conceptually simple

4. Slide 8-4 Digital Information (Binary) Pictures of the Tinker Toy computerPictures of the Tinker Toy computer. How the Tinker Toy computer works. How the Tinker Toy computer works.

5. Slide 8-5 Digital Information Processing Performance Speeds How Fast Are Computers? Two measures of throughput MIPS: 2 ^ 3 ==> 8 FLOPS: 3.14159 ^ 2.718 = 22.45186162 Supercomputers: MFLOPS; GFLOPS; TFLOPS; PFLOPS. The Prefixes of the S.I. The Prefixes of the S.I.

6. Slide 8-6 Digital Information Processing Performance Speeds Q: If a supercomputer can execute 1 GFLOPS, one instruction requires how much time to execute? A: 1 nanosecond. Q: If a supercomputer can execute 1 PFLOPS, one instruction requires how much time to execute? A: ???

7. Slide 8-7 Information Processing Speeds  People MFLOPS: recite 1..1M; 2 sec/recitation; 2Msec = 33,333 min. == 23 days GFLOPS: recite 1..1G; 3 sec/recitation; 3Gsec = 50M min. == 34K days = 100 yrs TFLOPS: recite 1..1T; 6 sec/recitation; 6Tsec = 200K yrs

8. Slide 8-8 Neurobiology 10 11 neurons, each connected to 10 4 others Switching Speed: 10 -3 sec. vs.computer: 10 -10 sec. Yet humans are able to make surprisingly complex decisions, surprisingly quickly. (eg) 10 -1 sec. for infant to visually recognize its mother

9. Slide 8-9 Neurobiology the information- processing abilities of biological systems must follow from highly parallel processes distributed over many neurons  Artificial Neural NetworksArtificial Neural Networks

10. Slide 8-10 Artificial Intelligence Research: Basic Premise Genus:Information Processing System (IPS) / \ Species: Biological Computers Systems  Both species governed by same principles

11. Slide 8-11 AI Research Scientific Metaphors The heart is a pump The brain is a computer (IPS) Metaphor  “The heart has its reasons of which reason knows nothing.”“The heart has its reasons of which reason knows nothing.” -- Blaise Pascal

12. Slide 8-12 Digeratus: Alan TuringAlan Turing During WWII Turing worked at Bletchley Park, Britain's codebreaking centre, & was responsible for German naval cryptanalysis. He devised a number of techniques for breaking German ciphers, including the method of the bombe, an electromechanical machine that could find settings for the Enigma machine.Enigma machine

13. Slide 8-13 The Turing Test for Intelligence: "Computing machinery and intelligence." (1950) The Turing test is a proposal for a test of a machine's capability to demonstrate intelligence: A human judge engages in a natural language conversation with one human and one machine, each of which try to appear human; if the judge cannot reliably tell which is which, then the machine is said to pass the test.

14. Slide 8-14

15. Slide 8-15 Five Categories of Information 1. Rover photos of Mars. Category: ?Rover photos of Mars 2. 100 Kdigits of PI. Category: ? 100 Kdigits of PI 3. Clerk's Prolog, Canterbury Tales. Category: ? Clerk's Prolog 4. Prelude & Fugue in C, J.S. Bach. Category: ? Prelude & Fugue in C 5. A statement in a computer program. Category: ? A statement in a computer program

16. Slide 8-16 Five Categories of Information Q: Which of the 5 categories is this? 01011100 11101111 00010000 11110000 A: It could be any one of the 5 (eg) How bit maps are used to represent images in computers.bit maps

17. Slide 8-17 Why Do Computers Use Binary? Nine Rungs of the Computer Inferno 1. Physics level. 2. Device Level: TransistorsTransistors 3. Gate Level: AND, ORANDOR PandA = TandF (p. 212) “Logic is the foundation of reasoning, and the foundation of computing. By associating true with presence & False with Absence, we can use the physical world to implement the logical world. This produces Information Technology.”

18. Slide 8-18 Why Do Computers Use Binary? 4. Machine Level: full adder a water adder flip-flop (stores one bit)