Introduction to Computing

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

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

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

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

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

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

The pieces How are computers built? How are computers programmed? How are computers networked?

Buying a machine An ad for a computerAn ad for a computerAn ad for a computerAn ad for a computer

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

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…

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

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

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)

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

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.

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

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

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

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

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

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

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 and displays web pages Differing network connections –Client/server vs. peer-to-peer –How networks facilitate music sharing

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

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

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

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?

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

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

Pause for experiment

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

Practical Details Lectures Tuesday/Thursday –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)

Practical Details Paperless course –All assignments, lecture notes on web Go to 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

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