Computers 101. Lecture 1

Transcription

1 Computers 101 Lecture 1

2 Announcements Open House/Software install help session TODAY! Sitterson 008: 1pm 6pm Get help installing course software and meet the UTA team Have this done by Wednesday 1/17 Office hours start Tuesday 10am 8pm in SN008 First quiz Friday 1/19 in class

3 And now, for some

4 Hardware vs. Software Hardware the physical stuff inside your computer All boils down to electrical circuits Software programs (code) that has been written to run on the computer Each program is just a list of instructions for the hardware to execute

5 Hardware CPU Central Processing Unit The brain of the computer responsible for executing the instructions you write in code (~3 billion per second) GPU Graphics Processing Unit Draws to the screen

6 Hardware RAM Random Access Memory Fast memory located close to the CPU, holds data currently being accessed Hard Drive Secondary storage that is slower but much bigger (holds data not currently being accessed)

7 Putting it all Together Motherboard - switchboard that all hardware connects to in order to communicate with each other Hardware communicates through motherboard on buses Memory bus USB bus etc.

8 Think Pair Share What is a computer?

9 Peripherals (I/O) Input devices: Mouse, keyboard, game controller When they receive input, the store data at predefined memory locations Output devices: Monitor, headphones, printer They read data from predefined memory locations and translate that to some human consumable output CPU sees everything as memory! Memory-mapped I/O

10 Bits The bit is the fundamental unit of the computer Each bit can hold two states: 0 or 1 2 bits can represent 4 values 3 bits can represent 8 values 4 bits 2 bits = # of values possible

11 KB? MB? GB? 1 byte = 8 bits Fun fact: Fred Brooks is so baller he actually invented the byte Kilo, Mega, Giga, Tera 1 KB = 1,000 bytes 1 MB = 1,000 KB = 1,000,000 bytes 1 GB = 1,000 MB = 1,000,000,000 bytes 1 TB = 1,000 GB = 1,000,000,000,000 bytes

12 The Memory Hierarchy Computers store data in 3 distinct places Demonstrates the classic computer science tradeoff of space versus time Faster speed -> less space More space -> slower speed

13 CPU cache Small but really fast Memory that resides directly on the CPU Holds the upcoming instructions that the CPU will execute ~1 MB ~20 nanosecond access time (1 second = 1,000,000,000 nanoseconds) 15 million times faster than you can blink your eye

14 RAM RAM: Random Access Memory Holds the instructions (code) of the currently executing program Also holds any data that program may need Volatile all data is erased when computer shuts down ~10 GB ~100 nanosecond access time

15 Secondary Storage (aka Hard Drive) Magnetic, spinning disk (~7000 RPM) HIGH failure rate Holds large files like pictures and videos Stores data not actively in use by currently running program Up to several TB in size ~5,000,000 ns access time (5/1000 th of a second)

16 Aside BACK UP YOUR DATA In this course, ALL work is done on the computer A hard drive crash can be catastrophic and WILL HAPPEN to several of you this semester Dozens of free services out there Google Drive, Dropbox, icloud, OneDrive (free 1 TB for UNC students!!) You don t have to backup everything, but at least do it for the important stuff

17 The Fundamental Pattern Input Input Input Algorithm Output

18 The Fundamental Pattern From the scale of single lines of code to complete programs, this pattern of thinking is pervasive Input Input is data given to an algorithm An algorithm is a series of steps Input Input Algorithm Output An algorithm has some effect, outcome, or output

19 The Fundamental Pattern Flour Buttermilk Butter Salt Baking Soda Recipe Southern Biscuits

20 The Fundamental Pattern Think for a minute about where this pattern exists in the real world (not recipe!) or on your phone Pair with your neighbor(s) to discuss We'll share!?????????

21 The Fundamental Pattern - Tinder Potential Matches Swipes IF two people swipe each other right THEN match! Output: Bae

22 Software Operating System First program to run when computer is turned on Performs essential functions including: Manage CPU time Allocate memory Provide access to I/O devices (drivers) Applications (Apps) Generic term for any other kind of software Runs at a layer above the operating system Applications Operating System Hardware

23 Internet of Things Everyday objects with small computers embedded within Connected to the internet so they can communicate with one another Examples?

24 Programs Set of instructions for a CPU to follow We will write many programs both in lecture and on problem sets First one will be a greeting card for your mom! Our programs will be written in Typescript Language for the web written by Microsoft

25 Programming Languages Different programming languages are good for different projects Want to write an operating system? C Want to write a web app? Javascript/Typescript Like scientific computation? MATLAB/Python We choose Typescript Not because It is the best language (no such thing) It is the simplest (google Brainf**k) Because TS can be run on any device that has a web browser Good beginner language

26 Programming Languages Programming languages like Typescript are known as high-level languages These languages get translated by a specialized program into a lower level language known as assembly Assembly is then translated to machine code (1 s and 0 s) that the computer can interpret as instructions to execute

27 Next Class We will write our first program! Come prepared with all software installed