1. What Is Computer Science?
The study of computers (concrete artifacts) and their uses
The study of computing (abstract processes)
The study of what can be computed (automated solutions to problems)
Adapted from the materials of Prof Lambert at WLU:

2. Abacus (5th Century B.C.)

3. Pascaline (1643)

4. Jacquard’s Loom (1805)

5. Babbage’s Difference Engine (1832)

6. Hollerith’s Census Machine (1890)

7. Harvard’s Mark I (1947)

8. Apollo 11 Project (1960s) Margaret Hamilton,
director of software engineering at NASA

9. Microcomputers (1972-)

10. Robots (2000-)

11. Embedded Computers (2000-)

12. Three Fundamental Ideas of CS
Information processing
Algorithms
Automation

13. Information Processing
Began over 2500 years ago with the invention of writing in ancient Mesopotamia and Greece
Rhetoric: use of symbols in ordinary writing
Mathematics: use of symbols to represent abstract systems of ideas and chains of reasoning
Computing: automatic symbolic information processing

14. An Algorithm Is . . .
A description of a series of steps that leads to the solution of a problem
Examples:
Make a pizza from scratch
Give directions to the soccer field
Change a flat tire on an automobile

15. Example: Make Pancakes
Beat two eggs
Add 2 Tb. brown sugar
Add 1/2 cup of milk
Add 1 Tb. melted butter
Add 1 cup self-rising flour
Pour batter onto griddle and cook until done

16. Automation If we can design an algorithm to solve a problem . . .
. . . then we can (in principle) build a real computer to automate the solution

17. A Universal Machine
Some computers are highly specialized, others are general purpose
A general purpose computer can (in principle) automate the solution of any algorithmic problem

18. Algorithms and Programs
Algorithms are abstract ideas, pure thought-stuff
Programs express algorithms in particular programming languages, such as
Basic
FORTRAN
C++
Java
Python
Lisp

19. Programs and Computing
A stored program computer can be reused for many different types of problems
Build a general-purpose computer once and then build specialized solutions as needed

20. Hardware and Software
Hardware consists of the devices - microphones, speakers, processor, and memory storage - necessary to run any programs
Software consists of programs used to solve problems, including the processing of other programs

21. Overview of Software Data types, literals and variables
Input and output (I/O)
Definite iteration: repeat something a specified # of times
Control: use if statements and Boolean logic
Loops: execute a number of steps, then loop back to the top to do it again
Conditional iteration: repeat until something is true
Strings, lists, databases