1. Basic Computer Hardware

2. Computer Systems Components CPU (s) RAM = main memory, memory Input/Output devices Secondary storage devices

3. Microprocessor Basics A microprocessor (“chip”) is an integrated circuit designed to process instructions Usually the most expensive component of a computer

4. Central Processing Units Different types/brands of CPUs (chips) Intel / AMD the main makers (others like IBM, TI, ARM for mobile devices) determine what kind of OS and software you can run Rated by number of “cores” Rated by clock speed (MHz) “system clock” NOT the calendar on your Desktop to an engineer, a “clock” is a device that puts out a regular signal serves the same purpose as a conductor in an orchestra – keeps the components all in sync measured in Hertz (1 Hz = 1 cycle/signal per second) Benchmark – software used to test and evaluate CPUs Overclocking – pushing it beyond rated speeds http://cpuboss.com/compare-cpus

5. CPUs Other ways to compare CPUs Cache memory Level 1 (L1) nearest the CPU Level 2 (L2) Level 3 (L3) farthest from CPU, shared between several CPUs typical capacity 10 MB, 16 MB hits and misses Word size 32 bits or 64 bits 64 bit usually backwardly compatible, will run older software too Other processors GPU = graphics processing unit

6. Cache Memory Cache memory usually built into chip with CPU Very short distance for data to travel Data that is used repeatedly stored there temporarily “cache hits” and “cache misses”

7. Computers in the Environment Chip manufacture Computer chips and CPUs are made of silicon Youtube How do they make Silicon Wafers and Computer Chips? (8 mins and linked video - 10 mins)How do they make Silicon Wafers and Computer Chips? Acids, powerful lasers, and hazardous chemicals are used to etch circuitry onto silicon wafers Chip production takes place in a clean room to keep chips from being contaminated and to keep hazardous materials from escaping Chip production is largely done by robots to keep from exposing humans to the hazards of the plant

8. Computers and Heat Chips can melt if they get hot enough Keep your computer area and case clean! Let the air circulate Vacuum out dust from case Components all age faster when they are hotter than they should be Some Motherboards will shut down if they sense the temperature is too high

9. Can you upgrade a CPU? Depends on the Motherboard, does it have a socket that the CPU will fit? Usually costs enough that it makes sense economically to buy a new machine Overclocking Pushing the components to operate faster than the manufacturer’s specifications Usually causes the components to fail sooner, shortens lifespan

10. Random Access Memory (RAM) Temporary holding area for data, application program instructions, and the operating system instructions Volatile – needs power to hold its contents (information) Capacity measured in Megabytes, Gigabytes PC systems usually have between 2 GB and 8 GB

11. Virtual Memory If a system doesn’t have enough REAL RAM to hold the programs which you want to run, the Operating System can swap pieces of the programs out to the Hard Drive. They stay there until they are needed by the running of the program. Then they get swapped back into RAM while some code that is NOT being used gets sent out to the Hard Drive. This is a slower process than having actual RAM on your machine – the hard drive is slower to access than RAM, and the act of swapping is overhead that takes time. But it makes it possible to run programs which really should not run on your computer. This is why adding more real RAM to a computer will speed up its processing.

12. Secondary Storage Magnetic storage Optical Storage Solid State Storage

13. Magnetic storage – Hard drives Hard drives use magnetic heads to sense very very small magnetic spots on the surface of disks (platters) that are rotating very fast (> 7000 RPM) The spots represent binary data Hard drives should NOT be “jiggled” around while they are working – the head is moving so close to the disk surface that this can cause a “head crash” Head crashes can damage your head, access arm and the data under the head at the time – they can make the drive unusable

14. Optical Storage Optical devices (CD, DVD, Blu-ray) use lasers to read and write on their media Some devices actually use the laser to dig microscopic pits in the surface – those are the “R” types – Read – they can’t be erased once written RW types (Read, Write) use dyes at different levels in the medium to record and erase data many times

15. Solid State Storage Stores data in patterns of electrons in writeable, erasable circuitry Started small, with memory (flash) sticks Now found in SD cards of all sizes and capacities Also in Solid State drives Rivals to magnetic drives, speed not quite as fast, prices still high No moving parts Can be changed when it is given power, if power is off data is frozen Watch out for static electricity with memory sticks and cards!

16. Peripherals Devices added to the main computer to add abilities input (keyboard, mouse, trackball, Wii controller, microphone) output (printer, monitor, 3d-printer, speakers) storage (external hard drives, memory sticks, cameras, phones) They are called “peripheral” because they are NOT at the center of the computer (that’s the CPU and RAM)

17. Display Devices An LCD display produces an image by filtering light through a layer of liquid crystal cells LCD displays need a backlight, to come from behind the crystal cells, be changed to the desired color and then exit the display and strike your eyes. Gradually, Cold Cathode FL backlighting technology is being replaced by low-power light-emitting diodes (LEDs) Chapter 2: Computer Hardware17

18. Types of displays http://www.rtings.com/info/lcd-vs-led-vs-plasma/how-they-work LCD + fluorescent back lights LCD + LED back lights Plasma http://www.landrysolutions.com/Plasma_LCD_explainations.htm Chapter 2: Computer Hardware18

19. Display Devices Screen size Dot pitch Width of viewing angle Response rate Resolution Color depth Power usage Weight Chapter 2: Computer Hardware19

20. Printers An ink-jet printer has a nozzle-like print head that sprays ink onto paper A laser printer uses the same technology as a photocopier (path of paper through a laser printer in image on right) Chapter 2: Computer Hardware20

21. Printers Printer features Resolution (dpi) Print speed (ppm) Operating costs (cost per page) Duplex capability (print on both sides of paper) Memory for buffer Networkability Recycle or refill? Chapter 2: Computer Hardware21

22. Peripherals, slots and ports

23. Protecting your computer Power surges and brown outs Lightning strikes nearby Protect your computer with Uninterruptible Power Supply (UPS) – more expensive, usually also has battery backup to allow you time to shut the computer down correctly when the power fails. Usually provides better protection, faster fuses. Most have a place to plug in your telephone line also. Phone lines can carry surges too! Surge suppressor – usually in the form of a power strip with a fuse. They are cheap, not always fast enough to protect your computer.

24. Buying a computer Decide on the USE of the computer playing games, school work, social media, web hosting, special needs, business Decide on platform = OS and hardware Apple = Mac, iPhone, iPad PC = Intel (or compatible) CPU, Windows OS or Linux OS other special purpose Decide on budget Think about the future how long do you want to use this computer? is there something you will want to do later that you don’t do now? Consider your “legacy” what format are your documents in right now? you want to stay compatible What kind does your school/work use? you may need to be compatible

25. E-waste (Computers and Society) Recycling electronics is good BUT… Make sure you know where the waste goes Many third-world countries accept the waste and do not know how to handle/treat it Ewaste is toxic Who is responsible for recycling the device? The consumer? The manufacturer? The government? Chapter 2: Computer Hardware25