Copyright © 2007 Heathkit Company, Inc. All Rights Reserved PC Fundamentals Presentation 41 – Input/Output Ports

2 Objectives At the end of this presentation, you will be able to:

3 Explain the advantages of serial transmission over parallel transmission in today’s high speed computers. List the major characteristics of the Universal Serial Bus and the IEEE-1394 Interface. Recognize USB and IEEE-1394 connectors and cables. Compare and contrast USB and IEEE Explain why USB and IEEE-1394 cause additional concerns for the IT Manager. Explain the purpose of PC Cards. Recognize “legacy” serial and parallel ports and briefly explain how they are used.

4 PC are going high speed serial. Ethernet Input/output ports Expansion buses such as PCI Express. Hard Disk Drive Interfaces

5 Parallel Data Vs. Serial Data Parallel Serial

6 Skew Ideal Reality

7 Jitter Ideal Reality

8 Serial transmissions are not as prone to these problems. All bits are transmitted over the same conductor. The construction of the cable is simplified. Serial cables are cheaper. Longer cable runs are allowed. The construction of the transmitter and receiver are simplified.

9 Additional Advantages of Serial Transmissions Easy to configure. Fewer computer resources are required.

10 High-Speed Serial Bus Architectures Universal Serial Bus (USB) IEEE-1394 (Firewire)

11 Universal Serial Bus (USB) An industry-wide cable bus standard (developed in 1995). Brings plug and play to peripheral devices. A single USB channel can handle up to 127 peripheral devices. Does not require a separate adapter card. It allows for fast, bi-directional communication between a host computer and hot-pluggable peripherals.

12 The USB Ports

13 The USB Icon

14

15 Feature...Feature... It’s an external expansion bus using cables (completely outside the PC).

16 Feature...Feature... It’s an external expansion bus using cables (completely outside the PC). Can daisy chain 127 peripherals to a port.

17 Feature...Feature... It’s an external expansion bus using cables (completely outside the PC). Can daisy chain 127 peripherals to a port. Plug and Play, hot-pluggable, automatic configuration.

18 Feature...Feature... It’s an external expansion bus using cables (completely outside the PC). Can daisy chain 127 peripherals to a port. Plug and Play, Hot-pluggable, automatic configuration. USB 1.1 allows 12 Megabits/second data transfer rates. USB 2.0 allows 480 Megabits/second data transfer rates.

19 Feature...Feature... It’s an external expansion bus using cables (completely outside the PC). Can daisy chain 127 peripherals to a port. Plug and Play, Hot-pluggable, automatic configuration. USB 1.1 allows 12 Megabits/second data transfer rates. USB 2.0 allows 480 Megabits/second data transfer rates. USB peripherals can often be powered by the USB bus (+5 Volts DC).

20 Feature...Feature... It’s an external expansion bus using cables (completely outside the PC). Can daisy chain 127 peripherals to a port. Plug and Play, Hot-pluggable, automatic configuration. USB 1.1 allows 12 Megabits/second data transfer rates. USB 2.0 allows 480 Megabits/second data transfer rates. USB peripherals can often be powered by the USB bus (+5 Volts DC). Five meter peripheral connections.

21 USB Peripherals Cartridge, Tape, and Floppy Drives Modems Microphones Printers, Scanners ISDN, T1 Interfaces (Network Applications) Input devices such as Mice, Joysticks, Keyboards, Graphics Tablets Multimedia Game Equipment

22 USB Peripherals (Cont.) Digital Cameras Digital Speakers Video Monitors Hubs Telephony (PBX, Digital Telephones)

23 USB Components Host Function

24 Powering USB Components A bus-powered device gets all its power from the USB cable. Self-powered devices have their own power supply.

25 The USB Hub Port 1Port 2Port 3 Port 4Port 5Port 6 Plugs into Host or other Upstream Device USB Devices plug into Ports

26 Component Examples Hub Host Function (with built-in Hub) Function Scanner Function

27 USB Cable has Four Wires Vbus :+5 Volts DC to power USB devices D+ :Data D- :Data Gnd :Ground

28 USB Cable Vbus (+5VDC) Outer Jacket Shield Gnd D- D+ Twisted Pair

29 USB Connector Shapes (Plugs and Sockets) Type A Type B Rectangular Connectors Square Connectors

30 IEEE-1394 Firewire i.link

Port Icon 1394 Icon

32 IEEE-1394 Speeds 100 Megabits/Sec 200 Megabits/Sec 400 Megabits/Sec 800 Megabits/Sec 1.6 gigabits/Sec (Proposed) 3.2 Gigabits/Sec (Proposed) IEEE-1394a IEEE-1394b

33 IEEE-1394 can accommodate a maximum of 63 devices per port.

34 USB versus Firewire

35 USB versus Firewire (IEEE-1394) Both are cable expansion buses. Both use a small cable with peripherals that are hot-pluggable. Both use daisy-chaining to connect peripherals. USB’s top speed is 480 Megabits/second while Firewire runs at 100, 200, and 400 Megabits/second, with much higher speeds in the works.

36 USB versus Firewire (IEEE-1394) continued… Firewire cable has 6 conductors (4 data/clocks and 2 power) while USB has 4 conductors (2 power and 2 data). USB is aimed primarily at the PC peripheral market while Firewire is used for computer interfaces to consumer electronic products like digital camcorders, VCRs, digital televisions, and other audio visual products.

37 Legacy I/O Ports Serial Port Parallel Port VGA (Video) Port

38 25-Pin Serial Port 9-Pin Serial Port

Serial Ports Legacy Serial Ports

40 Parallel Port and VGA Port VGA Port Parallel Port

41 The PC Card

42 PC Card Personal Computer Memory Card International Association (PCMCIA) Originally designed for adding memory to portable computers A universal bus that can accommodate any type of device Can be used with desktop PCs with the proper adapter “Hot Swapping” capability

Copyright © 2007 Heathkit Company, Inc. All Rights Reserved PC Fundamentals End