1. Digital Sound

3. Computer Sound To convert an analog wave into digital, converters use a process called sampling DEF: Sampling- the height of the sound wave is sampled at regular intervals of time (fractions of a sec)

4. Sound Compression --MP3 Music is sampled 44,100 times per second. Separate samples are taken for the left and right speakers in a stereo system. The goal of the MP3 format is to compress a CD-quality song by a factor of 10 to 14 without losing the CD-quality sound.

5. MP3 The MP3 compression algorithm makes use of limited human perception If you were think of an algorithm to compress sound, how would you go about eliminating bytes? Why is MP3 a good compression algorithm?

6. A byte can also be part of a computer program A computer program is a sequence of instructions in the machine language of the computer –Move (move a byte from disk to memory, or from memory to the printer) –Add – add two binary numbers –Compare – check two binary numbers for equality, greater than, or less than

7. Computer HardwareComputer Hardware Next two weeks, we’ll be covering Computer hardware –Goals Conceptually understand how the HW of a computer works How to be a better PC customer/consumer.

9. The Progression of a computer’s “ease of use” 1950’s 1960’s - 1970’s 1980’s - today Why was this good?

10. Computer Hardware’s Basic Function All about manipulating binary data

11. Hardware has the Components that… Process data Store the data Communicate the data Input data Output data

12. How We Process & Store Data (CPU)– blue Basic internals of a computer box

13. CPU’s Qualities Central Processing Unit

14. Yesterdays Processor The first microprocessor was the Intel 4004, introduced in 1971. Prior to the 4004, engineers built computers either from: –collections of chips – discrete components (transistors wired one at a time).

15. The Home Computer had a microprocessor called the Intel 8080 –Intel 8080 was a complete 8-bit (which means what?) computer chip, introduced 1974. Yesterdays Processor

16. Examples of CPUs on Today’s Market  Pentium III/IV is a CPU, or “processor” made by Intel  Celeron is a less expensive, slower processor made by Intel  PowerPC is a processor made by Motorola and is the basis of the Macintosh

17. Today’s Processor Made of Chips of silicon Your desktop computer has a CPU chip that is made of silicon. –Silicon is a semiconductor material ( partial resistance to electricity) –It is mounted on a carrier –It has metal pins that plug into the motherboard Remember: computer understands electrical impulses, silicon is conducive to this

18. Processors 2 main components

19. Another Hardware Component CLOCK

20. Clock Speed Speeds of the Clock are measured in? What do we mean by an 800 MHz processor Today, clock speeds go into the GHz

21. Clock Speed vs. Computer Speed Question: Why can’t I crank up my processor to 100mhz?

22. Clock Speed True: The clock controls the speed of which operations inside the CPU are happening True: the larger the CPU speed, the faster the computer can be True: The CPU speed is dependent and can only be as fast as the other supporting computer hardware True: Bottlenecks inhibit speed

23. Parameters that limit speed Transmission delays on the chip –How other hardware components are interacting with the clock Heat buildup on the chip.

24. Bus- red

25. MOTHERBOARDMOTHERBOARD

26. Ports