1. The Central Processing Unit Processor and Main Memory

2. Learning Intentions We are learning to: State the function of the processor Describe the differences between RAM and ROM Make comparisons between computer systems using processor speed and main memory size. State the function of graphics and sound cards.

3. The Computer System INPUT OUTPUT BACKING STORAGE Processor MAIN MEMORY

4. Processor and Main Memory Processor - Deals with all the movement of data and the calculations that need to be carried out. Main Memory-Used to store programs and data Processor Main Memory

5. Makes of processor

6. Clock speed A5 processor (IPAD) Intel Core i7 Clock speeds are a measure of how powerful a processor is. 1 Megahertz (1 MHz) = 1 million pulses per second 1 Gigahertz (1 GHz) = 1000 million pulses per second 800MHz 3.2 GHz

7. Clock speed examples TypeSystemProcessor Speed SmartphoneBlackBerry Bold 9780 624 MHzSlowest TabletSamsung Galaxy Tablet 2 1 GHz LaptopAsus Ultrabook1.6 GHz DesktopHP Desktop PC3.4 GHzFastest

8. The Main Memory The main memory can be either RAM or ROM. Random Access Memory is the working space of the computer. It holds all the programs and data you are currently using. When you are using MS Word it has been loaded from your computer’s hard disk into RAM. The unsaved work you have typed so far is also held in RAM.

9. Read Only Memory Read Only Memory is used by the computer to store data permanently. In computer systems ROM is used to store the Operating System of your computer. Stores the programs that run MP3 players, Washing machines, Central Heating system and other devices in your home It is very difficult to change the data held in ROM

10. RAM vs ROM Random Access MemoryRead Only Memory Read and WriteRead Only Data can be changedData CANNOT be changed Data is lost when power is switched off - Temporary Data is kept when power is switched off - Permanent Holds all the data and programs currently in use Holds instructions the computer and devices need to carry out their function

11. Complete the table in your jotter Computer System Processor SpeedMain Memory (RAM) Samsung Galaxy S smartphone 1 GHz512 Mb Yarvik Zania 10 Tablet Acer Apsire Ultrabook ASUS Essentio Desktop PC Using www.pcworld.co.uk

12. Answers Computer System Processor SpeedMain Memory (RAM) Samsung Galaxy S smartphone 1 GHz512 Mb Yarvik Zania 10 Tablet 1.2 GHz1 Gb Acer Apsire Ultrabook 1.7 GHz4 Gb ASUS Essentio Desktop PC 3.3 GHz4 Gb

13. Graphics Card Specialised piece of hardware used to process the images and videos you see on your screen. They have their own processor and memory. The CPU then has the time to get on with processing other data. The best graphics cards allow your games to run smoothly.

14. Graphics Card- In Your Jotter Graphics CardProcessor speed (frequency) MemoryPrice PNY Ge Force 8400 ASUS AMD Radeon HD6770 ASUS NVIDIA Geforce GTX 680 Using www.pcworld.co.uk

15. Answers Graphics CardProcessor speed (frequency) MemoryPrice PNY Ge Force 8400 520 MHz512 Mb£ 19.97 ASUS AMD Radeon HD6770 850 MHz1 Gb£99.99 ASUS NVIDIA Geforce GTX 680 1201 MHz2048 Mb (2Gb) £468.00

16. Sound Cards The sound card is used to capture and output audio data. They improve the quality of sound output from games and multimedia. Sample Rate: A measure of the quality of the sound that has been captured. Measure in KHz

17. Sound Card shopping- In your jotter Graphics CardTest Frequency (Sample Rate) Price CREATIVE Sound Blaster X-Fi Xtreme ASUS Xonar HDAV1.3 Using www.pcworld.co.uk

18. Answers Graphics CardTest Frequency (Sample Rate) Price CREATIVE Sound Blaster X-Fi Xtreme Up to 96 kHz£39.97 ASUS Xonar HDAV1.3 192 kHz£129.97