Introduction to Computer Hardware

1. CMPTR Chapter 2 – Part 1 (Hardware)

2. The CPU • The central processing unit (CPU or processor) is a computer chip that performs the calculations and comparisons needed for processing; it also controls the computer’s operations. • Many CPUs today are multi-core CPUs; that is, CPUs that contain the processing components or cores of multiple independent processors in a single CPU. CMPTR Chapter 2: Computer Hardware

3. The CPU • The CPU clock speed measures of the number of instructions that can be processed per second. • Cache memory is a special group of very fast memory circuitry located on or close to the CPU that is used to speed up processing by storing the data and instructions that may be needed next by the CPU in handy locations. CMPTR Chapter 2: Computer Hardware

4. Memory • Memory is chips located inside the system unit that the computer uses to store data and instructions while it is working with them. • RAM (random access memory) is used to store the essential parts of the operating systemwhile the computer is running, as well as the programs and data that the computer is currently using. CMPTR Chapter 2: Computer Hardware

5. Ports and Connectors CMPTR Chapter 2: Computer Hardware

6. Flash Memory • Flash memory is a chip-based storage medium that represents data using electrons. CMPTR Chapter 2: Computer Hardware

7. Keyboards QWERTY Layout The QWERTY keyboard layout was patented in 1968. Frequently used pairs of letters were separated in an attempt to stop the typebars from intertwining and becoming stuck, thus forcing the typist to manually unstick the typebars. Dvorak Layout The Dvorak alternative keyboard layout reduces finger movement and can increase typing speed.

8. Keyboards for other languages In China, most computer users type out their Chinese in transliteration, using the standard Roman alphabet keys on a QWERTY keyboard. To generate a character, you type out its sound according to the same spelling system—called Pinyin—that represents the name of China's capital with the word "Beijing." The computer automatically converts the Pinyin spelling to the correct Chinese characters on the screen.

9. Pointing Devices A pointing device is an input device that moves an onscreen pointer (arrow or insertion point) to allow the user to select objects on the screen. How many pointing devices can you name? • Mouse • Pen • Touchscreen • Trackball • Touchpad • Pointing Stick • Joystick, • steering wheel, etc.

10. Touch-screen Future Car Touch-screen iPad iPhone and Android touch-screen keyboards Restaurant POS

11. Scanners and Readers • A scanner captures an image of an object—usually a flat object, such as a printed document, photograph, or drawing— in digital form, and then transfers that data to a computer. • The quality of scanned images is indicated by optical resolution, usually measured in the number of dots per inch (dpi). Scanners produce an image after scanning. OCR (Optical Character Recognition) is software that looks at the image and reads the text. The output will be a text document. CMPTR Chapter 2: Computer Hardware

12. Scanners and Readers • A barcode is an optical code that represents data with bars of varying widths or heights. CMPTR Chapter 2: Computer Hardware

13. Scanners and Readers • Radio frequency identification (RFID) is a technology that can store, read, and transmit data located in RFID tags. • RFID tags contain tiny chips and radio antennas; they can be attached to objects, such as products, price tags, shipping labels, ID cards, assets, and more. • The data in RFID tags is read by RFID readers. CMPTR Chapter 2: Computer Hardware

14. Optical Mark Readers Magnetic ink character recognition (MICR) readers. Used by the banking industry.

15. Biometric Readers Retina Scan Identification Is being used by the military

16. Audio Input • Audio input is the process of entering audio data into the computer. • Speech recognition systems enable the computer to recognize voice input as spoken words and require appropriate software. • Music input systems are used to create an original music composition or arrangement, or to create a custom music CD. CMPTR Chapter 2: Computer Hardware

17. Display Devices • The most common form of output device is a display device. • Presents output visually on some sort of screen. CMPTR Chapter 2: Computer Hardware

18. Display Devices • Most computers today (as well as most television sets) use the thinner and lighter flat-panel displays. • Display devices that use electrically charged chemicals or gases to display images. • Flat-panel technologies include: • Liquid crystal display (LCD) • Light emitting diode (LED) • Organic light emitting diode (OLED) • Interferometric modulator (IMOD) display • Plasma display • 3D Display CMPTR Chapter 2: Computer Hardware

19. Display Technologies - CRT The Cathode Ray Tube dates back to around 1900. An electric charge created an electron beam that illuminated a phosphor-coated screen. This led to the discovery of the electron. Modern CRT’s have 3 electron guns – red, green, and blue. Modern CRT 1939 GE Television

20. Display Technologies - LCD Liquid Crystals were discovered in 1888. Electric currents cause the crystals to change their orientation and can be used to create a pixel on a screen. The first liquid crystal display was in 1968.

21. Display Technologies - Plasma A plasma display has hundreds of thousand cells (pixels) each containing xenon and neon gas. Electrodes in each cell (pixel) can charge the plasma gas causing it to ionize and emit photons. The first plasma display was developed in 1964.

22. Printers 3D Printers http://www.youtube.com/watch?v=ZboxMsSz5Aw CMPTR Chapter 2: Computer Hardware