Welcome to Comp 411!

1. Welcome to Comp 411! I thought this course was called “Computer Organization” 1) Course Mechanics 2) Course Objectives 3) Information David Macaulay

2. Meet the Crew… Lectures: Montek Singh (SN-245) Office Hours: TBA TA: John Hansen Book: Patterson & HennessyComputer Organization & Design 3rd Edition, ISBN: 978-0123706065, June 2007 (However, you won’t need it for the next couple of weeks)

3. Credits • These slides were developed by Leonard McMillan and adapted by Gary Bishop and me.

4. Problem sets will be distributed on the web and are due back on the date indicated before the lecture begins. Usually you will have one week to complete each set. Late problem sets will not be accepted, but the lowest two problem-set scores will be dropped. I will attempt to make Lecture Notes, Problem Sets, and other course materials available on the web Before Class on the day they are given. Course Mechanics Grading:Best 8 of 10 problem sets 40% 2 Quizzes 30% Final Exam 30%

5. Comp 411: Course Website http://www.cs.unc.edu/~montek/teaching/spring-08 Will be up later today!

6. Goal 1: Demystify Computers • Strangely, most people (even some computer scientists) are afraid of computers. • We are only afraid of things we do not understand! • I do not fear computers. I fear the lack of them. • - Isaac Asimov (1920 - 1992) • Fear is the main source of superstition, and one of the main sources of cruelty. To conquer fear is the beginning of wisdom. • - Bertrand Russell (1872 – 1970)

7. Goal 2: Power of Abstraction • Define a function, develop a robust implementation, and then put a box around it. • Abstraction enables us to create unfathomable machines called computers. Why do we need ABSTRACTION… Imagine a billion --- 1,000,000,000

8. Circuit Board: 8 / system 1-2G devices Integrated Circuit: 8-16 / PCB .25M-16M devices Module: 8-16 / IC 100K devices MOSFET Cell: 1K-10K / Module 16-64 devices Scheme for representing information Gate: 2-16 / Cell 8 devices The key to building systems with >1G components Personal Computer: Hardware & Software

9. Wait! I think I see a bug in the DIV logic. Got thatone offthe web. Sure hope it works. What do we See in a Computer? • Structure • hierarchical design: • limited complexity at each level • reusable building blocks • Interfaces • Key elements of system engineering; typically outlive the technologies they interface • Isolate technologies, allow evolution • Major abstraction mechanism • What makes a good system design? • “Bang for the buck”: minimal mechanism, maximal function • reliable in a wide range of environments • accommodates future technical improvements

10. Computational Structures • What are the fundamental elements of computation? • Can we define computation independent of the substrate on which it is are implemented?

11. Our Plan of Attack… • w Understand how things work, by alternating between low-level (bottom-up) andhigh level (top-down) concepts • w Encapsulate our understanding using appropriate abstractions • Study organizational principles: abstractions, interfaces, APIs. w Roll up our sleeves and design at each level of hierarchy w Learn engineering tricks - history - systematic design approaches - diagnose, fix, and avoid bugs

12. How to get an A • Or least get past the C wall • Read the book! • Do the work. • Ask questions. • Learn to deal with complexity.

13. Who I am

14. Who are you? • Name? • Major? • Why are you taking this class? • One thing we might not know about you?