1. 1 LESSON 3 – HARDWARE AND PERIPHERAL DEVICE CSE 101 Summer2013

2. 2 This Lesson Includes Following section

3. 3 What is I/O Device ?  Input Device  Sends data INTO a system Eg: Keyboard, Mouse, Scanner, Optical Input Device, Digital Camera, Joystic, Microphone, Pen, Touch Screen  Output Device  data OUT from a system to another medium Eg. Monitor, Printer, Projector, Sound Card, Speaker, Video Card

4. 4 Input Device - Keyboard One of the main input devices used on a computer, a PC's keyboard looks very similar to the keyboards of electric typewriters, with some additional keys. Type of Keyboard  Standard / Enhanced Keyboard  Non-Standard or special use tye of keyboard Standard Keyboard A standard computer keyboard has about 100-104 keys. Most keyboards use the QWERTY layout, named for the first six keys in the top row of letters. Non-Standard Keyboard Special purpose keyboard are called non standard keyboard A keyset or chorded keyboard Virtual Keyboard Touch screen keyboard Foldable keyboard

5. 5 Keyboard Layout – Most keyboards have keys arranged in five groups:  Alphanumeric Keys  Numeric Keypad  Function Keys  Modifier Keys  Cursor-movement keys Input Device – Key Board (Cont.) How Keyboard works?

6. 6 What is Mouse? The mouse is a pointing device. You use it to move a graphical pointer on the screen. The mouse can be used to issue commands, draw, and perform other types of input tasks. Input Device - Mouse Using the mouse involve five techniques. Varients of the mouse: Trackballs Trackpads Integrated pointed Devices

7. 7 A type of camera that stores the pictures or video it takes in electronic format instead of to film. Input Device – Digital Camera 1.Light passes through the lens of a digital camera 2.The image is focused on an array of CCD(Charge-coupled device) 3.The CCD generate a continuous,analog electrical signal that goes to an ADC (Analog –to-digital converter) 4.ADC sends the digital information to a DSP (Digital signal processor) 5.The DSP manipulates the image, adjusts the contrast and detail in the image, compresses the data and sends the data to camera’s storage medium How digital Camera Works:

8. 8 Optical Input Device- Barcode Reader Scanner OCR OMR Barcode Readers Bar code readers can read bar codes—patterns of printed bars. Input Device – Optical Input Device Scanner Hardware input device that allows a user to take an image and/or text and convert it into a digital file, allowing the computer to read and/or display the scanned object. OCR (Optical Character Recognition ) – Optical character recognition, usually abbreviated to OCR, is the mechanical or electronic translation of images of handwritten, typewritten or printed text into machine-editable text. OMR (Optical Mark Reader) – Optical mark recognition' is the process of capturing data by contrasting reflectivity at predetermined positions on a page. Quick data entry for MCQ

9. 9 Touch-screen systems accept input directly through the monitor. Touch screens use sensors to detect the touch of a finger. They are useful where environmental conditions prohibit the use of a keyboard or mouse. Touch-screen systems are useful for selecting options from menus. Input Device – Touch Screen

10. 10 Monitor Also called a video display terminal (VDT) a monitor is a video display screen and the hard shell that holds it Output Device - Monitor Categories of Monitors Monitors are categorized by the way they display colors :  Monochrome – One color on a black background  Grayscale – Shades of gray on a white or off-white background  Color – From 16 to 16 million unique colors Monochrome Grayscale Color  Cathode ray tube (CRT) monitors  Flat-panel displays Monitors are categorized by the technology they use:

11. 11 Output Device – CRT Monitor CRT Monitors In CRT monitors, electrons are fired at phosphor dots on the screen. The dots are grouped into pixels, which glow when struck by electrons. In color CRTs, each pixel contains a red, green, and blue dot. These glow at varying intensities to produce color images. Flat Panel Monitor Most flat-panel monitors use liquid crystal display (LCD) technology. Passive matrix LCD uses a transistor for each row and column of pixels. Active matrix LCD uses a transistor for each pixel on the screen. Thin-film transistor displays use multiple transistors for each pixel.

12. 12 Comparing Monitor When comparing monitors, we mainly compare on major 4 features, 1.Resolution & Viewing Quality 2.Refresh Rate 3.Dot Pitch 4.Size Output Device – Monitor Fast scanning = Quick refresh (less flicker)

13. 13 V ideo Controllers The video controller is an interface between the monitor and the CPU. The video controller determines many aspects of a monitor's performance, such as resolution or the number of colors displayed. The video controller contains its own on-board processor and memory, called video RAM (VRAM). Output Device – Monitor VRAM Graphic intensive applications such as games require plenty of VRAM. Video Control Board with Monitor Cable

14. 14 A PC projector connects to a PC and is used to project images on a large screen. Many PC projectors provide the same resolutions and color levels as high-quality monitors. Digital light processing (DLP) projectors use a microchip containing tiny mirrors to produce very sharp, bright images. Output Device – PC Projector

15. 15 Multimedia PCs come with a sound card, speakers, and a CD- ROM or DVD drive. A sound card translates digital signals into analog ones that drive the speakers. With the right software, you can use your PC to edit sounds and create special sound effects. Output Device – Sound System

16. 16 Printers fall into two categories: Impact printers use a device to strike an inked ribbon, pressing ink from the ribbon onto the paper. Non-impact printers use different methods to place ink (or another substance) on the page. Impact Printer Non-Impact Printer Output Device – Printer An external hardware device responsible for taking computer data and generating a hard copy of that data. Printers are one of the most used peripherals on computers and are commonly used to print text, images, and/or photos.

17. 17 W hen evaluating printers, consider four criteria: I mage quality – Measured in dots per inch (dpi). Most printers produce 300 – 600 dpi. S peed – Measured in pages per minute (ppm) or characters per second (cps). I nitial cost – Consumer printers cost $250 or less, but professional printers can cost thousands of dollars. C ost of operation – This refers to the cost of supplies used by the printer. Output Device – Printer Types of printers:

18. 18 Dot matrix printers are a common type of impact printer. A dot matrix printer's print head contains a cluster of pins. The printer can push the pins out to form patterns in rapid sequence. The pins press an inked ribbon against the paper, creating an image. Output Device – Dot Matrix Printer Lower-resolution dot matrix printers use nine pins. Higher-resolution models have 24 pins. Speed is measured in characters per second (cps). Some dot matrix printers print 500 cps. Performance: How Dot Matrix printer works?

19. 19 Ink jet printers are an example of non-impact printers. The printer sprays tiny droplets of ink onto the paper. Ink jet printers are available for color and black-and-white printing. Output Device – Ink Jet Printer How Ink jet printer works? Ink jet printers offer speeds of (2 – 4 pages per minute ppm) and resolution (300 – 600 dots per inch dpi), comparable to low-end laser printers. Ink jet printers are inexpensive and have low operating costs. Performance:

20. 20 How Laser printer works? Laser printers provide resolutions from 300 – 1200 dpi and higher. Black-and-white laser printers usually produce 4 – 16 ppm. Laser printers produce higher-quality print than ink jet printers, but are more expensive. Performance: Output Device – Laser Printer Laser printers are non-impact printers. They use heat and pressure to bond particles of toner to paper. Laser printers are available for color and black-and-white printing.

21. 21  A thermal impact printer or electro thermal printer is a type of printer that uses heated pins to "burn" images onto heat-sensitive paper. These types of printers are commonly used in calculators and fax machines; and although they are inexpensive and print relatively fast, they produce low resolution print jobs. Output Device – Thermal Printer  A thermal printer, thermal transfer printer, or thermal wax-transfer printer is a high quality printer that commonly utilizes a thermal wax ribbon that melts a colored wax onto the paper creating near photo-realistic images.

22. 22 LED printers were developed by Casio and are printers capable of printing at the same or close to the same quality as most laser printers. LED printers work much like laser printers but utilize a LED panel that recreates the image on a negatively charged drum. The areas where the light hits the drum become less charged, which attracts toner. The printer then transfers the toner from the drum to the paper and applies intense heat to fuse the toner to the paper Output Device – Led Printer

23. 23 Print shops and publishers use these printers to create high- quality color images: Output Device – Snapshot Printer

24. 24 Storage Device Computer data storage is referred to as storage or memory, which can save digital data. Type Of Memory

25. 25 Storage Device – Primary Storage Device - RAM Type of RAM A Primary Storage Device also known as main Memory. Main memory keeps track of what is currently being processed. It's volatile, meaning that turning the power off erases all of the data. For example, computer RAM is an example of a primary storage device.

26. 26 Storage Device – Secondary Storage Device - ROM ROM – Read Only Memory –Pronounced rahm, acronym for read-only memory, computer memory on which data has been prerecorded. Benifit of Using ROM –Once data has been written onto a ROM chip, it cannot be removed and can only be read. Unlike main memory (RAM), ROM retains its contents even when the computer is turned off. ROM is referred to as being nonvolatile, whereas RAM is volatile. USES of ROM –Most personal computers contain a small amount of ROM that stores critical programs such as the program that boots the computer. In addition, ROMs are used extensively in calculators and peripheral devices such as laser printers, whose fonts are often stored in ROMs. Type of ROM  Programmable read-only memory (PROM),  Erasable programmable read-only memory (EPROM)  Electrically erasable programmable read-only memory(EEPROM)

27. 27 Storage Device – Secondary Storage Device Secondary Storage Device – Auxiliary Storage Device Auxiliary storage holds what is not currently being processed. This is the stuff that is "filed away", but is ready to be pulled out when needed. It is nonvolatile, meaning that turning the power off does not erase it. Auxiliary Storage is used for: Input - data and programs Output - saving the results of processing So, Auxiliary Storage is where you put last year's tax info, addresses for old customers, programs you may or may not ever use, data you entered yesterday - everything that is not being used right now.

28. 28 Storage Device – Secondary Storage Device The two Secondary storage technologies are magnetic and optical.

29. 29 Storage Device – Magnetic Device How Magnetic Storage Device Works. A magnetic disk's medium contains iron particles, which can be polarized—given a magnetic charge—in one of two directions. Each particle's direction represents a 1 (on) or 0 (off), representing each bit of data that the CPU can recognize. A disk drive uses read/write heads containing electromagnets to create magnetic charges on the medium. As the medium rotates, the head writes the data.

30. 30 Storage Device – Magnetic Device All magnetic disks are similarly formatted, or divided into areas, called  Tracks  Sectors  Cylinders TRACKS: A track is a circular ring on one side of the disk. Each track has a number. TRACKS: A track is a circular ring on one side of the disk. Each track has a number. Disk Sector: A disk sector is a wedge-shape piece of the disk, shown in yellow. Each sector is numbered. Disk Sector: A disk sector is a wedge-shape piece of the disk, shown in yellow. Each sector is numbered. Track Sector: A track sector is the area of intersection of a track and a sector, shown in yellow. Track Sector: A track sector is the area of intersection of a track and a sector, shown in yellow. Cluster: A cluster is a set of track sectors, ranging from 2 to 32 or more, depending on the formatting scheme in use. Cluster: A cluster is a set of track sectors, ranging from 2 to 32 or more, depending on the formatting scheme in use.

31. 31 Storage Device – Magnetic Device Cylinder A cylinder comprises all the tracks (on every usable platter surface) that can be accessed by the read/write heads while the actuator assembly remains stationary.

32. 32 Storage Device – Magnetic Device When a disk is formatted, the OS creates 4 areas on its surface.

33. 33 Storage Device – Optical Device How Optical Storage Works An optical disk is a high-capacity storage medium. An optical drive uses reflected light to read data. To store data, the disk's metal surface is covered with tiny dents (pits) and flat spots (lands), which cause light to be reflected differently. When an optical drive shines light into a pit, the light cannot be reflected back. This represents a bit value of 0 (off). A land reflects light back to its source, representing a bit value of 1 (on).

34. 34 Other Storage Device

35. 35 How Computer Process Data – Factors Affecting Processing Speed More RAM = Better Performance!

36. 36 Fall 2012 Any Question