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Chapter 8—USB and IEEE-1394 Ports and Devices
• Check the power usage for the USB bus in the Power dialog
box of the operating system.
• Verify that the USB device is drawing no less than 50mA and
no more than 500mA.
• Use the Windows Device Manager to verify proper operation
of the USB port; adjust IRQ settings if necessary to avoid
conflicts with other devices.
• Install the latest USB device drivers for the device and the
operating system; USB devices that work in Windows 98
might not be supported by other versions of Windows.
• If a printer doesn’t work properly with the “correct” USB
driver, try using a compatible driver for an older model as a
workaround.
• Install the latest firmware for the USB device; bad firmware
creates “ghost” versions of devices in the Device Manager
when the device is unplugged and reattached.
• Verify that the USB root hub (port) is assigned an IRQ; normally
IRQ 9 is used if available. Make sure IRQ steering is
working if all available IRQs are already assigned to other
ports.
• Use high-speed (heavily shielded) cabling for high-speed
devices, such as printers, scanners, and network connections.
• Separate low-speed from high-speed devices by attaching
them to separate USB ports.
• Assign USB controllers to Controller ID 1 if not detected by
the game.
• Use the smallest number of hubs possible; some versions of
Windows can’t use over 5 USB hubs (some devices double as
hubs).
• Before you purchase a USB device, verify device driver support
for your operating system; Windows 2000 supports USB
devices, but many vendors are slow about supplying USB
drivers for Windows 2000.
• When possible, buy devices that can be connected by either
a USB port or a so-called “legacy” port (PS/2 keyboard/mouse
port, serial port, parallel port, or SCSI port) to enable you to
use the device even if you have problems with your USB
ports or peripherals.