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Announcements The course is now up on UB Learns Assignment 1 will be posted this Sunday Submit Assignment 1 via UB Learns, or demonstrate it to your TA Assignment 1 is due in 2 weeks (2/13). Computer Parts. Everybody knows these. Keyboard Mouse Display System Unit CD Drive
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Announcements • The course is now up on UB Learns • Assignment 1 will be posted this Sunday • Submit Assignment 1 via UB Learns, or demonstrate it to your TA • Assignment 1 is due in 2 weeks (2/13)
Everybody knows these • Keyboard • Mouse • Display • System Unit • CD Drive • USB ports for devices • Wireless connection to the Internet • Documents / emails / pictures
Only computer people know these • Memory • Disk storage and Files • Ports
The memory model • Everything starts with this: “Computer memory is the source of all information and activity within a computer” • The Hard Drive is NOT computer memory
What it looks like “memory location 17 contains 0110 1110” location 8 values, restricted to 0’s and 1’s
25 24 23 22 21 20 19 18 17 0 1 1 0 1 1 1 0 Billions of these
Why ones and zeros? • Because in its simplest form, information is either the presence, or absence of something. • Computer circuitry can only sense the presence or absence of electricity. • Like a light being on or off • A door opened or closed • Called a “state”: true/false, yes/no, up/down, • All electrical information is the presence (1) or the absence (0) of electricity
25 24 23 22 21 20 19 18 17 0 1 1 0 1 1 1 0 Action Response Translation From Numerical Representation Translation to Numerical Representation
How computers use info • Numbers! • Everything is a number! • The letter “A” is stored as the number 65 • The letter “B” is stored as the number 66 • The color RED is stored in three numbers as 255 0 0
The information chain: An entity A numerical representation Represent that Number as 0s and 1s Letters, symbols, colors, shapes, commands, actions, sounds, notes, music, voices, words, ANYTHING! Industry Standard Suitable for memory
Problems to solve • How do you represent “Entities” as numbers? • The number of numbers, and the size of the numbers will be huge… • How do you translate different, LARGE numbers into 1’s and 0’s?
remember • A number is just a quantity • The quantity 26, means 26 of something piled up