25-pin serial port on a serial device (modem) 25-pin end of
serial cable connects to modem and 9-pin end connects to computers
serial port
Slide 5
PinSignalPinSignal 1Protected ground14Secondary transmitted
data 2Transmitted data15 Transmit timing signal 3Received
data16Secondary received data 4Request to send17Receive timing
signal 5Clear to send18Unassigned 6Data set ready19Secondary
request to send 7Signal ground20Data terminal ready 8Data carrier
detector21Signal quality detector 9Reserved for data set
testing22Ring indicator 10Reserved for data set testing23Data rate
selector 11Unassigned24External timing signal 12Secondary carrier
detector25 Unassigned 13 Secondary clear to send
Slide 6
Slide 7
MaleFemale NOTE: Line colors are not intended to represent wire
colors.
Slide 8
Slide 9
Send one byte 10110011 Receive one byte 10110011
Slide 10
Centronics 1284 Type B Mini-Centronics 1284 Type C DB-25 1284
Type A
Slide 11
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Connects to parallel port on the computer Connects to
device
Slide 13
PS/2 keyboard port PS/2 mouse port Cable PS/2 mouse (device)
PS/2 connector
Slide 14
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Type B connector connects to USB device Type A connector
connects to USB port on the computer or on a hub
Slide 16
Type B connector connects to USB port on devices Connects to a
USB port on the computer or another hub USB hub Type A connector
connects to USB port on the computer or a hub
Slide 17
5-volt power supply is carried along with the USB signal.
Allows small devices, such as handheld scanners or speakers, to use
power from the PC, rather than requiring their own power cables.
Devices are plugged directly into a 4-pin socket on the PC or hub
using a rectangular Type A socket. A USB bus distributes power
through each port. This allows low-power devices that normally need
their own power adapters to be powered through the cable. Hubs may
get all of their power from the USB bus (bus- powered), or they may
be powered from their own AC adapters.
Slide 18
SymptomPossible ProblemSolution USB devices dont work. USB
support not enabled in the BIOS. USB BIOS support must be enabled
to assign an IRQ to the PCI USB host bus controller. Cant connect
USB devices. No USB port on the system. Install a PCI to USB
adapter card in the system. Devices dont function or arent
detected. USB 1.0 system with cable over 5 meters. Reduce cable
length to 5 meters. Device cannot be seen in Device Manager.
Operating system does not support USB. USB device failure. Windows
95 provides limited USB support. Upgrade to Windows 98, Windows
2000, or Windows XP. USB device displays an unknown device icon in
Device Manager. If the USB host controller but not the Root Hub
appears, there could be a possible problem with the USB.INF file.
Remote the USB host controller from Device Manager and then click
Refresh. Common USB Power Problems
Slide 19
4-pin 6-pin
Slide 20
FireWire device FireWire 6-pin connector FireWire port