Structure of a computer

KS3 Curriculum

• Computers are devices for executing programs• Not every computer is obviously a computer (most

electronic devices contain computational devices)• Basic architecture: CPU, storage (e.g. hard disk, main

memory), input/output (e.g. mouse, keyboard)• Computers are very fast, and getting faster all the time

(Moore’s law)• Computers can ‘pretend’ to do more than one thing at

a time, by switching between different things very quickly

Not every computer is obviously a computer

• Not every computer is obviously a computer (most electronic devices contain computational devices)

• Students can research how many devices they can find that contain a microprocessor.

Devices that contain a microprocessor

Personalphoneswatchescalculatorscomputers and laptopscamerasiPods (iPads, other mp3 players, etc.)WII and X-boxes

Computers:infrared keyboards and micedisk drivesswitcheshubs

Commercial devices:cash tillssupermarket bar code scannersvending machineslottery ticket dispensing machinesprintersfaxescopiersautomatic door openers credit card processorsATM machines

Industryvehicles (cars, airplanes, boats, trains, trucks, etc)navigational systems (tomtom, loran, etc)

Home:clock/radiosovensmicrowave ovenswashing machinesdriersstereo systemsTVsDVD playerssatellite/cable boxesthermostatsair conditionersmotion detectors smoke detectorsburglar alarm systems

Medical:pace makersinsulin auto-injectorsheart monitorshearing aids

Military:smart bombsmissilesgunsturretstankssonic guns

Police:radar guns (for speeding tickets)infrared motion and camera systems (for traffic lights)uv locators (finding suspects and bodies)lie detectors

Municipal devices:traffic lightswalkie-talkies train ticket purchasing machines

Computers are devices for executing programs

When a program runs on a computer the processor repeatedly fetches and executes the next instruction from main memory, one at a time.

http://www.intel.com/content/www/us/en/education/k12/the-journey-inside/explore-the-curriculum/microprocessors/lesson2.html

Human CPU Activity

• Students can do a physical demonstration of the CPU operation. Get students to play the roles of:

• 1. Processor• 2. Clock• 3. Main memory registers (number them 1 to

6)• 5. A bus that transfers data from the Processor

to main memory

Human CPU Activity• Write some increasingly difficult mathematical equations on pieces of

paper e.g. 4+1, 7+9, 12+103, 45/5, 12^2, 9*4*5

• Give a piece of paper to each student who is a piece of main memory.

• To start the processor give the clock a watch with a second timer. Tell them to instruct the processor to fetch an instruction from main memory every 20 seconds. The processor must use the bus to get the instructions from one memory register at a time and work out the answer before the 20 seconds are up.

• Clock speed can them be increased (10 seconds, 5 seconds etc.) to see the result on the processor.

Extension tasks

• Make the clock tick faster – a real clock ticks at 3Ghz• Make the calculations more complex – then you can

use an extra student be a dual core processor. It can be easier if difficult work is shared.

• Simulate saving to the hard disk by having on area of memory much further away and harder to get to than the others.

• Simulate a cache by having one student stand next to the processor and remember repeated calculations.

Extension tasks

• Use the how computers work instructions to draw images that could appear on the screen

Doing a million things at once

Do you have any applications running at the same time?• music playing• streaming video• e-mail sending/receiving• gaming• writing• … at the same time…

Activity

• Use the workshop activity materials

Moore's law

• Moore's law is the observation that over the history of computing hardware, the number of transistors on integrated circuits doubles approximately every two years.

• Historic timeline• http://www.intel.com/content/www/us/en/

history/historic-timeline.html

Processors into the future

• Today’s high-end computer chips have as many as 16 cores. But Tilera’s top-of-the-line chip has 100. http://www.wired.com/wiredenterprise/2012/01/mit-genius-stu/

• http://blogs.howstuffworks.com/2011/04/20/how-fast-is-the-fastest-microprocessor-chip-now-and-in-the-future/

Starters/Plenaries

• Youtube Starter: From sand to chip - How a CPU is made

• http://www.youtube.com/watch?v=-GQmtITMdas

• Other Intel videos• http://www.intel.com/content/www/us/en/

education/k12/the-journey-inside/explore-the-curriculum/microprocessors.html

Starters/Plenaries

• Get students to look at PC adverts on the internet to see who can find the fastest processor.

• http://ark.intel.com/products/family/41877/Intel-Pentium-Desktop-Processor

Summary