PERIPHERAL DEVICES. Sno Isle Skills Center

Transcription

1 PERIPHERAL DEVICES Sno Isle Skills Center

2 Peripherals A peripheral is a hardware device that is controlled by software but is not part of the core architecture of the computer.. You must install both the hardware and the software. Most all peripherals require the following basic fundamentals: The hardware and firmware for the peripheral A device driver, BIOS, or both Available resources (IRQ, DMA, I/O address, memory addresses)*

3 Peripherals, cont. Some peripherals also require proprietary software that works in conjunction with the device driver. *

4 How the CPU Talks to the Peripheral The CPU uses INT (interrupts) to locate an entry in the interrupt vector table. This table, located in the lowest part of memory, stores the address of an interrupt handler, a program that will handle the request. The program is either a device driver or BIOS and will use I/O addresses to communicate with the device. Some devices may connect to a controller that manages the resources for it and other devices connected to the controller. PCI, USB, IEEE 1394 (FireWire)*

5 Hardware Devices Internal devices cheaper, difficult for average user to install External devices more expensive, easier to install because they install on a port that s already configured.*

6 Embedded BIOS on Devices Some devices have ROM chips with firmware that holds software RAM to use as temporary storage Jumpers and DIP switches for setting device IRQs, IDs, etc. Usually older devices.*

7 Using Ports and Expansion Slots for Add-on Devices Most PCs have: Two or more USB ports 1-2 PCI slots 2-6 PCIe slots New Ones might have a thunderbolt port 4-8 SATA ports*

8 Using Ports and Expansion Slots for Add-on Devices Older PCs may also have: One or two serial or COM ports, One parallel port or LPT port, One or two IEEE 1394 or FireWire port. These ports were usually located on an expansion board with older computers while they are typically built into the newer system boards.

9 Using Serial Ports: Serial ports transmit data one bit at a time. All serial ports are male and may have either 9 (DB-9) or 25 (DB-25) pins.

10 25 Pin male serial port (aka DB25) Serial Ports 9 Pin Male Serial Port 15 Pin female game/midi port

11 Serial Ports, cont. Serial ports have been around for decades. Can connect Modems Bar code readers Old mice Also known as RS-232 (this is the standard to which it conforms) Requires the use of a UART chip A chip that changes the parallel communications of the system bus to serial so the serial device can communicate with the computer.*

12 Serial Ports, cont. Also known as communication ports Communication is bi-directional, also known as Full Duplex Bits are sent one byte at a time down one line, received one byte a time on a receiving line Parallel also sends one byte at a time, but requires 8 lines for each byte Parallel ports are faster than serial ports, but in other situations, serial communication is faster than parallel communication.

13 The UART Chip: UART stands for Universal Asynchronous Receiver/Transmitter chip. It establishes and controls all serial communications Is also responsible for converting parallel data bits from the system bus into serial data bits. The UART chip controlling the port is partially responsible for the speed of the port. *

14 Take Quiz 5-3

15 Infrared Transceivers: Wireless infrared devices require an infrared transceiver that can connect directly to a serial or parallel port. May be PnP or you may have to install manually. Some system boards provide a 5-pin connection for its own proprietary IRDA-compliant infrared transceiver. If so, the transceiver mounts on the outside of the case with a wire going through a small hole in the case to the 5-pin connector. You will need to disable COM2 serial port because the transceiver uses the resources for that port.*

16 Using Parallel Ports Parallel ports designed for printers transmit 8 data bits at a time, parallel to each other. Cables should be no more than 15 feet, HP says 10. Although parallel ports were designed for printers, today's bi-directional parallel ports are also used for high-speed access to other external devices. Parallel ports are female 25-pin DB connectors.*

17 Parallel Connectors

18 I/O Cards

19 Using USB Ports USB ports are configured by the OS, making them easier to use. USB Standards USB 1.1=12 Mbps USB 2.0=480 Mbps USB 3.o=up to 4.8 Gbps How do I know if my computer supports USB 2.0? Open device manager and look for Enhanced USB host controller *

20 USB, cont. A USB cable has four wires, two for data, one for ground, and one to provide up to 5 volts of power to the device. *

21 USB types

22 USB types Changes 1.1/2.0/3.0

23 USB Wiring USB 2.0 USB 3.0

24 Using IEEE 1394 Ports Some system boards may contain IEEE 1394 or FireWire ports. These ports have two types of connectors: a 4-pin port that does not provide voltage to a device, and a faster 6-pin port that does.

25 IEEE 1394, cont. IEEE1394 uses isochronous data transfer which means that the data is transferred continuously without breaks. Can support up to 63 devices on one channel. This real-time data transfer is ideal for camcorders, VCRs, TVs, and digital cameras. *

26 IEEE 1394, cont. IEEE1394 A, supports speeds of 100, 200, or 400 Mbps, allows cable lengths up to 4.5 meters, and is hot-pluggable. IEEE 1394 B, will support speeds up to 3.2 gbps and extend the maximum cable length to 100 meters.*

27 Thunderbolt: Developed by Intel and introduced into Apple Macbook Pros in 2011 Allows multiplexing of data lines from PCIe and DisplayPort (on Macs) devices. One port supports up to six devices Thunderbolt on a Mini Display Port can only handle 4 lanes of output at no more than 5.4 Gb per second. With a thunderbolt port it s 2 input/2 output at a full 10 Gb per second. 20 pins*

28 Thunderbolt: Max length 3 meters 18 v bus power Originally conceived as optical, but switched to copper to provide powered port There is a lot of technology in the cable itself, so even if the device sending a message is noisy the cable can clean up and mux and demux a signal 1.0 named Cactus Ridge 2.0 named Redwood Ridge Runs at 20 Gbps and will only be built into computers, not into devices Supports 4K resolution on passthrough

29 Thunderbolt

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31 Thunderbolt vs USB 3.0 USB 3.0 Super Speed Thunderbolt Speed 4.8 Gbps 10 Gbs (in TB port) 5.4 Gbps in MDP Power for devices 4.5 watts 10 watts Cost $4.50 for 2 meter cable $50 for 2 meter cable Download 25 GB movie seconds 30 seconds Ubiquity Common uncommon

32 Take Quiz 4-2

33 Touchscreens There are three basic types of touchscreens: capacitive screen uses a thin electrically charged layer placed over the monitor screen. When touched, the charge moves from the capacitive surface to the touching object. The screen location of the touch is calculated and sent to the computer. This method blocks some of the light emanating from the monitor.

34 Touchscreens resistive screen uses a glass panel covered with two metallic layers (one conductive and the other resistive) separated by a very narrow gap and mounted over the monitor screen. When the screen is touched, the two metallic layers make contact and that location is calculated. This type of touchscreen also blocks some of the monitor's light emanation.

35 Touchscreens surface acoustic wave screen places tiny matching transducers across the screen surface from each other (one to send and the other to receive). When an object touches the screen surface, the signal is interrupted and that location is then calculated. This type of touchscreen does not visually impair the monitor.

36 Using PCI Expansion Slots The PCI local bus supports up to four PCI expansion slots on the system board. Used for fast I/O devices, PCI slots feature bus mastering that assigns resources to the jumperless PCI cards. Simply moving a card to a different slot changes the resources. *

37 Buses and their Bandwidth

38 PCI vs PCI Express PCI Parallel Communications Transmits in half duplex Bandwidth on the bus is shared with other PCI devices (like a hub) Devices can talk to each other, to some extent PCI Express Serial Communications Each 1x lane in PCI express can transmit in both directions at once Each device gets its own bandwidth (like a switch) Devices can talk to each other and work together

39 PCI Express 1x, 2x, 12x

40 SLI/Crossfire SLI Scalable Link Interface Nvidia Each card controls half the screen *Alienware also has its own technology, and is working on a FOUR card solution. Overkill? Crossfire ATI Splits screen In half, each card does half In tiles, one card renders every other tile Each card renders alternate frames

41 Video Cards

42 Video Cards Creating an image out of binary data is a demanding process. The graphics card first creates a wire frame out of straight lines.

43 Video Cards Then, it rasterizes the image (fills in the remaining pixels). Adds lighting, texture and color. For fast-paced games, the computer has to go through this process about sixty times per second. Without a graphics card to perform the necessary calculations, the workload would be too much for the computer to handle.

44 Parts of a Video Card A: GPU (w/heatsink and fan B: DVI-D digital connector C: VGA, analog connector D: Gold lead connectors E: VI/VO port (video in/video out) F: Heatsinks covering VRAM

45 Monitors Monitors have been called Cathode Ray Tubes (CRTs) Video Display Terminals (VDTs) CONsole (CON), which is the DOS device name; "the screen. The two main categories of computer monitors are cathode tube and Liquid Crystal Display (LCD).

46 CRT A CRT (monitor) is a vacuum tube with an electron gun at one end of the tube (the narrow end), and a large piece of glass at the other end (the wider end). The inside surface of the viewing pane is coated with a layer of dots made up of three different kinds of phosphor (a chemical). The electron gun is made up of three different electron beams. Each beam shoots a stream of electrons at the phosphors, with each beam making one type of phosphor glow. When we look at the glass face of the monitor, we're actually seeing through the glass to the backside of the phosphor layer. In monochrome monitors, there is only one layer of phosphors, either green or amber, and a single electron beam.

47 Measuring CRT Size diagonal measure of the tube Resolution Number of pixels on screen horizontal x vertical Display type Shadow mask metal screen full of holes Aperture grill ultra thin wires in a mesh that is brighter than shadow Aspect ratio: 4:3

48 Measuring CRTs Dot pitch Distance between pixels, smaller is better Refresh rate Amount of time for CRT gun to move from top to bottom Interlacing Draws the screen in two passes, evens then odds Green less power Flat flat glass, better picture

49 LCD Liquid crystals exist in either a solid or a near-liquid state, depending on electrical conditions. In their near-liquid state, the crystals can pass light. Crystals have a tendency to be straight (like rods) in their natural state, but they twist into a right angle under electrical stimulation. This capability of passing light when they're straight or turning at right angles and blocking light gave rise to the LCD panel. (It wasn't really alien technology, no matter what anyone tells you.) Liquid crystals rely on a background source of light to pass through each crystal. If light can pass through the crystal, our eyes can see it. When the crystal is turned off, it won't let light pass and we see an area of black. Each crystal can be either on or off, much like binary computer numbers can be either 0 (off) or 1 (on).

50 Plasma Each pixel is three fluorescent lights Fluorescent lights have plasma gas in them, hence the name The colors are red, green, and blue A grid of cells makes up the screen Each cell contains gas The screen has phosphorous on it Electricity is applied and when there is a differential, light lights up the phosphorous and emits color.

51 OLED Organic light emitting diode Solid state Have thin films of organic molecules that light up when electricity is applied Uses less light and less power than LCD and CRT and Plasma Brighter and crisper Only a 14, ,000 hours of lifetime (red and green is longer, blue is shorter)

52 Uses for OLED ards-mice/9836/zoom/ gure_03.jpg

53 Common Issues CRT interference from EMI and magnetic sources Degauss the screen to remove the magnetic field from the screen Dead pixels (LCD) very common. Most manufacturers allow a certain number of pixels

54 Take OLED Quiz