1

Note taking in EGR115

• notebook– slide number in margin. comments on the right.– write down vocabulary words– write down overall ideas– write down things that we repeat 4 or 5 times!– write down possible errors

• printout of slides– print 2 or 3 slides per page– draw arrows, add your comments– highlight

2

Introduction to Computers and Programming

1. History of computers (4 slides)2. What is a computer system?3. What is software?4. What is programming?5. Different languages6. Compiled vs. interpreted

History of Computers

Computers ≠ calculators

Computers are programmable. The first calculators were not programmable, hence not considered computers.

3History 1/4

4

1854 (~150 years ago) - Pioneer of modern computer!

Babbage’s difference engine

Device to subtract adjacent values in a column of numbers. Created for engineers in charge of creating tables of logarithms and trigonometric functions.

History 2/4

1943 (~70 years ago) .. came Colossus

• Primarily used for breaking the German codes during World War 2.

• It would crack Enigma Codes (codes that were cracked by exhaustively shifting text by arbitrary amounts). For example:

‘Zsszbj zs 9599’ would be ‘Attack at 0600’

5History 3/4

Finally, the von Neumann Architecture…

• The Von Neumann computer architecture is mostly what we still use today. The architecture separates a computer in 3 major parts:– The Central Processing Unit (CPU)– The computer memory– The Input/Output (I/O) devices

6

CPU + memoryScreen=output

Speakers=output Mouse=input

Keyboard=input

?

?

Knob=inputHistory 4/4

Software and programming?

• Microsoft Word, Excel, Guitar Hero, the address book in your cell phone, the electronic that starts a car, the avionics in an airplane… are all software that were written by people.

• Programming is the act of writing logical instructions that will be executed when people use the software.

• It is as difficult as learning to speak a foreign language, since the programmer is constrained to the vocabulary (specific keywords) and grammar (exact syntax) of programming.( ) ‘ ’ , ; if for else while switch case otherwise end input fprintf

7

8

A computer system today

• Keeping the von Neumann architecture, today’s computing systems combine both hardware and software.

– Hardware (i.e. what’s hard and can break..): mouse, keyboard, monitor, hard disk, printer, CD, DVD.

– Software i.e. the programs that describe the steps we want the computer to perform.

Trivia 1

• An actual DVD is:a) hardwareb) software

• The content on a Microsoft Office DVD is most likely:a) hardwareb) software

9

10

Categories of software

• Software contains the instructions the CPU uses to run programs.

• There are several categories, including:– Operating systems (OS) – manager of the computer system as a whole– Software applications – commercial programs that have been written

to solve specific problems– Language compilers - to ‘translate’ programs written by people into

something understandable by the machine (sometimes not needed)

Trivia 2

• Which type of software are these? ________

11

Trivia 3

• What type of software are these?____________

12

Generations of Languages used to write software

1) Machine language – also called binary language. Sequence of 0’s and 1’s.

2) Assembly language – each line of code produces a single machine instruction (add, subtract…)

3) High-level language – slightly closer to spoken languages.

13

add b,cadd a,b

a= a + b + c;

This line does the same as the two above.

14

Trivia 4

• Order these types of languages in the order they came out?– assembly language– machine language– high-level language

Finally… MATLAB

• Is an interpreted language – does not require compilation, but it does have a compilation step hidden from the user.

• Has an interactive environment –– “In the MATLAB environment, you can develop and execute programs

that contain MATLAB commands. You can execute a MATLAB command, observe the results, and then execute another MATLAB command that interacts with the information in memory, observe its results and so on.”

15

Internet vs. WWW?

• Internet is the “boss” of all communication tools, including www but also servers, etc…

16

Wrapping Up

• Computers vs. Calculators?• Evolution of computers from WW2?• Von Neumann Architecture?• Hardware vs. software?• Types of software?• Types of languages?• MATLAB?

17