HP XA manual Universal Serial Bus USB Controller, Other PCI Accessory Devices, Plug and Play

2 System Board

Devices on the PCI Bus

It is possible to mix a fast and a slow device, such as a hard disk drive and a a CD-ROM, on the same channel without affecting the performance of the fast device. The BIOS determines automatically, the fastest configuration that each device supports. However, in general, the IDE cable is recommended for CD-ROM drives, and the SCSI cables for hard disk drives.

Universal Serial Bus (USB) Controller

The USB controller is implemented as part of the PIIX4 chip. It is accessed through the PCI bus, and provides support for the two stacked USB connectors on the back panel. Over-current detection and protection is provided, but shared between the two ports.

USB works only if the USB interface has been enabled within the HP Setup program. Currently, only the Microsoft Windows 95 and Windows NT operating systems provides support for the USB.

The Microsoft Supplement 2.1 software called (called USBSupp.exe), which provides support of the Universal Serial Bus, can be obtained from the Hewlett-Packard World Wide Web site (refer to “Access HP World Wide Web” on page 21).

	Other PCI Accessory Devices
	PCI accessory boards are for high-speed peripheral accessories. A network
	board could already occupy one of the PCI slots. A diagram showing the PCI
	slots that are available for the desktop and minitower models is on page 27.
Plug and Play	The HP Kayak XA/ PC Workstations have a “PnP level 1.0A” BIOS and
	meets the “Windows 95 Required” level for Plug and Play. Accessory boards
	which are Plug and Play are automatically configured by the BIOS.

40