1. CSC 1 Introduction to Computer Science
Week 1

2. Week 1: Fundamental Concepts
What is computer science?
What is in a computer (von Neumann machine architecture)?
Types of computer systems.
Programming basics.

3. What is Computer Science?

4. Computer Science
Computer science studies information processes both artificial and natural [P. J. Denning].
Artificial: information processing systems and machines.
Natural: information processes in: biology, medicine, psychology, cognitive and behavior sciences, sociology, economics, chemistry, meteorology, neuroscience, physics, forensics, linguistics, philosophy, ………

5. E. Dijkstra
Computer science is no more about computers than astronomy is about telescopes.

6. Natural Information Processes
Biology and medicine. Computer models and algorithms to diagnose and treat disease (MRI, fMRI, CT). Computer models to track mutations of viruses. String algorithms for DNA sequencing.
Economics. Computer models to forecast economic conditions.
Forensics. Computer models and databases to identify evidence and discover forensic data.
Psychology, cognitive and behavior sciences. Computer models are used to shed light on human brains and nervous systems.

7. Natural Information Processes (2)
Linguistics. Computer based speech recognition. Machine translation.
Philosophy. Artificial intelligence, machine learning, and heuristic programming in knowledge representation and reasoning.

8. Body of Knowledge for the Artificial [P. J. Denning]
Algorithmic processes that describe and transform information: their theory, analysis, design, efficiency, implementation, and application.
Coordination and communication (Internet).
Structure and operation of computer systems, principles underlying computer system design and programming, effective methods for using computers for information processing tasks, and theoretical characterizations of their properties and limitations.

9. System and Application [P. J. Denning]
Systems: structures, mechanisms and schemes for processing information.
Software systems
Hardware systems.
Application: information processing tasks and their related data representations.
Numerical applications: weather forecast, global warming modeling, ……
Non-numerical applications: Second Life, robotics, social networks, protein structure prediction, ……

10. Subareas [P. J. Denning] Algorithms and data structures.
Programming languages.
Architecture.
Operating systems and networks.
Software engineering.
Databases and information retrieval.
Artificial intelligence and robotics.
Graphics.
Human computer interaction.
Computational science
Organizational informatics.
Emerging areas such as bioinformatics.

12. von Neumann Machine Architecture
What is in a Computer?
von Neumann Machine Architecture

13. von Neumann Machine Architecture
John von Neumann,

14. Salient Features Stored program.
Separation of processing from storage.
Predefined instruction set.
Instruction execution cycle.
Shared buses.
Sequential architecture.
Control flow vs. data flow.

16. Basic Functions of a Computer
Input Data
Process Data
Output Data
Store Data

17. Input Data Feeding information into a computer Common forms of input
Symbols – letters, words, numbers, etc.
Pictures (using a camera)
Sounds (using a microphone)
Common forms of input
Keyboard
Mouse
Often involves converting analog to digital
How is input fed into a computer – person, environment using devices….mouse, keyboard, audio

18. Process Data Analyze data, or use it in a computation.
Perform some action based on data.
Generate new data, or change existing data.
Processing is done in the CPU.
Processing is managed by a computer program.
Basic Terms:
Program – a sequence of instructions (with data) to accomplish a certain task
Process – a program in execution
Processor (CPU) - device where a program gets executed
How is input fed into a computer – person, environment using devices….mouse, keyboard, audio

19. Output Data Common forms of output
Monitor
Printers
Speakers (music and Sound)
Often involves converting digital signals to analog signals

20. Store Data Save data on a device for later use.
Data is always stored in digital form.
Common Forms:
Memory
CD ROM
Hard Disk
Flash Disk
Magnetic tape

21. Functions of a Computer
Process Data
Input Data
Store Data
Output Data

22. Functions of a Computer
Analog
Digital

24. Different Types of Computers
Computer Categories
Different Types of Computers

25. Computer Categories There used to be four categories
Personal computers
Workstation computers
minicomputers
mainframe computers
Today, computers can be categorized by
function
size
performance
cost

26. Today’s Computer Categories
Personal computers
Handheld computers
Console Computers
Mainframes
Supercomputers
Workstations
Servers

27. Personal Computers “Microcomputer” Designed for everyday users
Also known as a PC or “Personal Computer
Designed for everyday users
Desktop computers
Notebook or netbook computers
Tablet computers

28. Handheld Computers Designed to be used while being held
Called a PDA (Personal Digital Assistant)
A few examples:
Apple iPods
Cell phones
Palm & Handspring PDAs
Blackberry

29. Console Computers My game system is a computer? Examples include:
Has processors
Input data from joysticks
Output data (graphics and sound)
Has internet connection
Examples include:
Microsoft XBox 360
Sony Playstation 3
Nintendo Wii

30. Notebooks Similar to Personal Computers Also called a “laptop”
Hardware is different
Functionality is often the same
Slightly more expensive
Also called a “laptop”
“Netbook”:
Very small
Minimal functionality
Intended for web access while traveling

31. Mainframes & Supercomputers
Built for computing power
Can calculate complex data – fast
Excellent for complex simulations
Used by federal research labs and large corporations (banks)
Typically large – cabinet sized
Expensive

32. Workstation Computer
Computers designed for a specific group of users (Pixar Studio).
The term “workstation” has two meanings
Powerful desktop models
Computer on a network

33. Servers
A server sends data or offers services to other computers on a network
typically they have lots of storage (SAN)
run unattended – no users
any computer can be server – although not ideal
eBay, Google, Facebook, Myspace, Twitter, Amazon, ……
A client receives data or (service) from a server
Go to Riverside Hall 2011 to see some

35. Programs, Coding, Engineers & More
Programming Basics
Programs, Coding, Engineers & More

36. Programming Languages
series of symbols & words that form a meaningful pattern
This is true of natural languages such as English, Spanish, Hindi, Arabic, etc...
Programming
language used to write programs to be executed in computers
there are many different programming languages

37. Popular Programming Languages
C++ C#
Java
Fortran
Visual Basic
COBOL
…………

38. Algorithms A sequence of steps for carrying out a task Examples:
tying your shoes
driving to Sac State
making a peanut butter and jelly sandwich
withdraw money at ATM
Capture “the essence” in solving a problem
can be implemented into a computer program using some programming language

39. Procedural Programming
Traditional approach to programming
Programs
a sequence of instructions (statements)
statements run in order – from first to last
repetition is performed with “looping”
decisions are described as “if – then – else”

41. Graphically Representing Algorithms
Flow Charts
Graphically Representing Algorithms

42. Flow Chart Overview Graphical representation
each step is a shape (box, circle, …)
useful for conceptualizing an algorithm
easy to understand and visualize
Used to document how an algorithm was designed

43. Input / Output
Process Data
Input / Output

44. Start / End Indicates the start and end of an algorithm
Represented by a rectangle with rounded sides
There are typically two:
one to start the flowchart
one to end the flowchart

45. Input / Output Indicates data being: Represented by a parallelogram
inputted into the computer
outputted to the user
Represented by a parallelogram
Flowcharts can have many of this shape

46. Processes Indicates data: Represented by a rectangle
being processed
also called "calculations"
Represented by a rectangle
The most common shape in a flowchart

47. Decisions Indicates a conditional branch Represented by a diamond
describe a condition or a question
Has more than one outgoing branch, depending on the outcomes to the condition/question
Represented by a diamond

48. Get distance “d”
d < 5 ?
yes no
walk
drive

49. Describing an Algorithm with words
Pseudocode
Describing an Algorithm with words

50. What is Pseudocode? Description of an algorithm's logic
simpler than spoken English
looks like a program, but easier to read
It is often useful
to express some piece of the solution
without having to worry about every detail

51. Area of a Circle Pseudocode
Program: area of a circle
1.Get the value for the radius
2.Calculate the area (pi x radius2)
3.Output radius and area

52. Distance program… Pseudocode (compare with flowchart)
Program: decide between walk/drive
1. Compute distance to destination
2. If distance is less than 5
then walk
else drive