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CS session webpage http://csserver.evansville.edu/~hwang/f13-courses/cs101.html

Introduction sheet, turn in at the end of class

The CS session constitutes 1/3 of the final course grade for ENGR/CS 101

Lecture 1 ENGR/CS 101 Computer Science Session 1

What is Computer Science?

Bits to Brains

Binary digits (bits)

Binary numbers

ASCII encoding

Lecture 1 ENGR/CS 101 Computer Science Session 2

Short video by University of Washington

"Power to Change the World"

Study of how computer programs are written to solve problems using computation

Use an engineering approach to design and implement a computer program

But first, a look at a basic idea underlying computing

Lecture 1 ENGR/CS 101 Computer Science Session 3

A bit is a digit that can have value 0 or 1.

8 bits

10011101

1 byte

A byte is (a sequence of) 8 bits

A word is 16, 32, or 64 bits, depending on the machine architecture.

Lecture 1 ENGR/CS 101 Computer Science Session 4

Use the cards to help answer the following questions:

What cards can we use to show 3 dots? 6 dots?

11 dots?

What is the highest number of dots that we can represent with these cards?

What is the smallest number of dots we can represent with these cards?

Lecture 1

What is the pattern of the dots? How many dots would there be on a fifth card?

ENGR/CS 101 Computer Science Session 5

Arrange the cards like so:

Count from 0 to 15 dots by flipping over the cards

What is the pattern as you count?

Lecture 1 ENGR/CS 101 Computer Science Session 6

Each digit place represents a power of the base of the number in decimal. E.g.,

356

10

= 3 x 10 2 + 5 x 10 1 + 6 x 10 0

10011101

2

= 1 x 2 7 + 0 x 2 6 + 0 x 2 5 + 1 x 2 4 +

1 x 2 3 + 1 x 2 2 + 0 x 2 1 + 1 x 2 0 = 157

10

What is 1000111

2

in decimal? What is 97

10 in binary?

Lecture 1 ENGR/CS 101 Computer Science Session 7

Computers "speak" bits and bytes, but humans communicate using letters, words, and sentences.

Need to encode characters into bits. One such encoding is called ASCII (American

Standard Code for Information Interchange).

Alphabet-based

Ordering based on English alphabet

Extended for other languages' alphabet symbols

Lecture 1 ENGR/CS 101 Computer Science Session 8

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**109 e f g h a b c d k l **

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Lecture 1

**32 ! 33 , 44 **

ENGR/CS 101 Computer Science Session

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How many bits will it take to implement ASCII encoding of characters?

Can you find a mathematical equation to calculate the number of bits needed to represent a number n ?

Lecture 1 ENGR/CS 101 Computer Science Session 10

Decode the ASCII message on the worksheet

Write your first name in ASCII in binary

Turn in the worksheet and the introduction sheet before you leave.

Lecture 1 ENGR/CS 101 Computer Science Session 11