This document provides an overview of an introductory computer science course titled COS 111. The course will cover building a computer using basic logic gates and memory, using computers to process data and applications, networking computers and communication protocols, limitations of computation, societal issues, and applications of artificial intelligence. It will involve lectures, problem sets, labs, and a midterm and final exam. The goal is to help students from non-technical backgrounds understand how computers work at a basic level.

1. Introduction to Computing

2. When do you use a computer?
• Word Processing
• Web Surfing
• Instant Messaging/Email
• Music downloads/Games
• Air traffic control
• Car diagnostics
• Climate control

3. Why do you use a computer?
• Word Processing
– Improved communication
• Web Surfing
– Knowledge acquisition
• Instant Messaging/Email
– Community
• Music downloads/Games
– Entertainment

4. What do you need in a computer?
• Word Processing
– WYSIWYG
– Attached to printer/Email
• Web Surfing
– Network connection
• Instant Messaging/Email
– Network connection
• Music downloads/Games
– Network connection
– Disk space
– CD/ROM ?RW

5. When do you use a computer?
• Air traffic control
• Car diagnostics
• Climate control

6. What is a computer?
• Processor brains
• Memory scratch paper
• Disk long term memory
• I/O communication (senses)
• Software reconfigurability

7. What makes a computer special?
• Most complex object made by humans
• Communication mechanism
• Reconfigurability
• Moore’s Law

8. The pieces
• How are computers built?
• How are computers programmed?
• How are computers networked?

9. Buying a machine
• An ad for a computer

10. What’s in a Machine
• Processor (Pentium III 850 MHz)
• RAM (128 MB of SDRAM expand to 512 MB)
• Disk (20 GB)
• CD ROM/ CD RW/DVD/…
• 15" XGA TFT Display (1024x768 res.)
• 3.5" 1.44MB Floppy Disk Drive
• S3 Savage IX 128-bit AGP 2x graphics
– 8MB memory, 3D Hardware acceleration,
composite TV-Out support, …
• 16-bit Soundblaster Compatible Sound

11. What’s in a Machine (cont)
• 2 Type-I or Type-II slots or 1 Type-III slot
• 2 USB Ports
• Built-in 56Kbps V.90 Data/fax modem
• Built-in 10/100 Ethernet Adapter
• Also
– universal AC adapter,
– built-in Lithium-Ion battery,
– Microsoft Windows Millennium Edition,
– Encarta World Encyclopedia online version…

12. The machine
Core Machine
Communications
I/O
Text
Sound
Software
Power
Disk
RAM
Ports

13. Building an application
• Word (is a part of the Office application)
• Runs on Windows (an operating system)
• Runs on Pentium (a computer)
• Enhanced by connections to monitor, printer,
network
• Uses random access memory (RAM) to work on
document, disk (non-volatile) memory to store in
• Need a CD-ROM to install application

14. More for Less --Moore’s Law
• 1981 when I came to Princeton
– CS department machine
• $150,000 (now < $1,000)
• 700 Khz chip (now 1 GHz)
• 1 MB memory (now 128MB)
• 80 MB disk (now 40 GB)
• CD-ROM not yet invented (1983), CD-R (1989)
• Minimal Internet connection
• Communication 9600 bps (now 10 Mbps)

15. Moore’s Law 2
• $150,000 (now < $1,000)
– Factor 0f 150
• 700 Khz chip (now 1 GHz)
– Factor of 1500
• 1 MB memory (now 128MB)
– Factor of 128
• 80 MB disk (now 40 GB)
– Factor of 500
• Communication 9600 bps (now 10 Mbps)
– Factor of 1000

16. What about COS 111?
• COS 111 is intended for students from the humanities and
social sciences who want a one-course introduction to
computers and computer science. Emphasis is on
understanding how computers really work, starting with a
single switch, and showing step by step how to use just
that one kind of part to build the most interesting human-
made machine. Also addressed are essential limitations of
the computer, such as undecidability, as well as future
prospects for artificial intelligence and on-line access to
the world's knowledge. The laboratory is complementary
to the classroom work and explores a broad spectrum of
modern applications.

17. What does this mean?
• Building a computer
• Using a computer
• Networking the computer
• Understanding the limitations of the computer
• Social Issues
• Applications

18. What does this mean?
• Building a computer
• Using a computer
• Networking the computer
• Understanding the limitations of the computer
• Societal Issues
• Applications

19. Building a computer
• Start with simplest part – switch
• Build logic gates – AND/OR
– Use to solve logic problems
• Build memory
• Build processing power
– Arithmetic Unit
• Build simple programming language

20. What does this mean?
• Building a computer
• Using a computer
• Networking the computer
• Understanding the limitations of the computer
• Societal Issues
• Applications

21. Using a computer
• How to represent data
• How to manipulate data
• How to manage information
• Start with 2 applications
– Picture processing on the computer
– Sound processing on the computer

22. What does this mean?
• Building a computer
• Using a computer
• Networking the computer
• Understanding the limitations of the computer
• Societal Issues
• Applications

23. Networking the computer
• How do computers communicate
– Protocols TCP/IP, HTTP, FTP, …
• The InterNet
– What it is and where it came from
– How it transports email and displays web pages
• Differing network connections
– Client/server vs. peer-to-peer
– How networks facilitate music sharing

24. What does this mean?
• Building a computer
• Using a computer
• Networking the computer
• Understanding the limitations of the computer
• Societal Issues
• Applications

25. Understanding the limitations of the computer
• Algorithms for solving simple problems
• Harder problem
– Problems unlikely to be solved in our lifetime
– Problems unlikely to be solved in millennia
• Undecidable problems
– Problems that provably can never be solved

26. What does this mean?
• Building a computer
• Using a computer
• Networking the computer
• Understanding the limitations of the computer
• Societal Issues
• Applications

27. Societal Issues
• Digital rights management
– Old ideas of copyright law do not work
– When is sharing legal?
• Privacy
– Systems are not secure
– How much information should be public
• Safe communication
– Should you send your credit card over the internet?

28. What does this mean?
• Building a computer
• Using a computer
• Networking the computer
• Understanding the limitations of the computer
• Societal Issues
• Applications

29. Applications
• How well can computers
– Understand written text
– Understand spoken text
– Understand hand drawn pictures
– Play chess …
• Possibly a look inside a big program

30. Pause for experiment

31. What does this mean?
• Building a computer
– 6 lectures, 3 problem sets
• Using a computer
– 2 lectures, 1 problem set, 2 labs
• Midterm review and Midterm
– 2 classes
• Networking the computer
– 3 lectures, 2 problem sets, 3 labs
• Understanding the limitations of the computer
– 4 lectures, 2 problem sets, 2 labs (programming)
• Social Issues and Applications
– 3 lectures, 1 problem set, 1 lab

32. Practical Details
• Lectures Tuesday/Thursday 11-1230
– No class 9/18, 9/27
– Lecture notes will be online
– Class participation expected
• Labs
– Start in week of 9/24, due by Friday at 5PM
– Can do in lab sessions or elsewhere
– To be scheduled
• Problem Sets
– Handed out Thursday, due Tuesday (12 days later)

33. Practical Details
• Paperless course
– All assignments, lecture notes on web
• Go to http://www.cs.princeton.edu
• Click on fall courses
• Click on COS 111
• Problem sets
– Lowest score dropped
– Must do 7 of 9 to pass the course
• Labs
– Must complete all labs to pass the course
• Midterm and Final

34. Practical Details
• Problem sets 20%
• Lab reports 10%
• Midterm exam 25%
• Final exam 25%
• Class Participation 20%