Universal Serial Bus; (Usb) - Compaq Deskpro AP400 Supplementary Manual

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HITE APER
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Five stages of fixed equalization. The five stages of fixed equalization
incorporated in the electronics are used to "shape" the system frequency
response in various listening positions. The system frequency response is
manipulated to provide smooth, natural voice reproduction and high-quality CD
playback.
Electrical system gain staging. Gain staging is a key process in transforming
the individual piece parts into a unified audio system. Gain staging allows
Compaq to compensate for the different input levels that are generated by a
number of different audio sources, such as CD-ROM, wavetable, and line in.
The end result of the interaction between the susbystems is a well balanced, "no desktop
clutter," audio system capable of delivering clean, undistorted output at a level needed
to support an office environment.
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N I V E R S A L E R I A L
The Compaq Professional Workstation AP400 includes two Universal Serial Bus (USB)
ports.
USB is a peripheral bus standard developed by a group of PC and telecom industry
leaders including Compaq, DEC, IBM, Intel, Microsoft, NEC and NORTEL. USB
enables hot plug and play of computer peripherals outside of the workstation
eliminating the need to install boards into expansion slots and then having to
reconfigure the system. Workstations equipped with USB allow peripheral devices to be
automatically configured as soon as they are physically attached - without the need to
reboot or run setup. USB also allows up to 127 devices to run simultaneously with
peripherals such as monitors and keyboards acting as additional plug-in sites or hubs.
USB peripherals include telephones, modems, keyboards, mice, CD-ROM drives,
joysticks, tape and diskette drives, scanners, and printers. USB has a 12 Mbits/sec data
rate, compared to 115.2 Kb/s for serial ports and 2 Mb/s for enhanced parallel ports.
This improved transfer rate will accommodate a new generation of peripherals,
including MPEG-2 (compressed data) video-based products and digitizers.
Drawing its intelligence from the host workstation, USB detects when devices are added
and removed. USB automatically determines what host resource each peripheral needs,
including driver software and bus bandwidth, and makes those resources available
without user intervention.
Currently, there are different ways to implement USB. The Compaq Professional
Workstation AP400 implements the OpenHCI USB interface. OpenHCI reduces CPU
overhead for USB devices compared to other implementations and is fully compatible
with UniversalHCI.
Currently, Microsoft Windows NT Workstation 4.0 does not support USB, but future
versions are expected to include USB drivers that will allow the workstation to
recognize USB peripherals.
Compaq Workstations - Key Technologies
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