the truth about cats and usb

[Jonathan Mayer]

rather than having folks out there trust my slightly flawed earlier
synopsis, here's the real scoop from the horse's mouth: 
 
   Plug and Play technology has focused on the inside-the-box PC platform
   attributes. However, there is an industry mandate to bring Plug and
   Play outside the box for millions of new users that need maximum
   flexibility to reconfigure and attach external peripherals to their
   PCs. Universal Serial Bus will enable the PC to be easily reconfigured
   with new degrees of connectivity and interactivity.
 
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  Ease of Use
 
     * Completely Plug and Play means peripherals will be correctly
       detected and configured automatically as soon as they are
       physically attached
     * Hot attach/detach allows adding and removing devices at any time,
       without powering down or rebooting 
     * Uses a single connector for all devices with no way to plug it in
       wrong  
 
  Telephony Connection
 
     * Enables easy PBX and digital telephone connectivity without
       specialized add-in cards
     * USB uses Enhanced Time Division Multiplexing (eTDM) to support 
       high speed digital telephone trunk interfaces, like ISDN PRI, T1
       or E1 lines
     * USB plus Windows Telephony API provides foundation for
       PC/telephone integration
     * Enables country by country standards conformance and homogolation
       outside the box
 
  Flexibility
 
     * A single connector type for many uses, including devices that in
       the past used serial ports, parallel ports, the keyboard port, the
       mouse port, and game ports as well as new kinds of devices
     * All kinds of devices can be hooked to the PC through the same
       connector simultaneously - modems, printers, mice, joysticks,
       scanners, keyboards, etc.
     * Uses less real estate than existing ports (particularly important
       for laptops)
     * Reduces requirement for PC slots, allowing footprint reduction for
       desktop systems
 
  Gaming Connection
     
     * Low-cost connection for multiple simultaneous input devices such
       as joysticks, keyboards and tablets
     * Ample bandwidth for new digital gaming peripherals such as digital
       joysticks, game pads, virtual reality goggles and data gloves
 
  Broad Industry Support
 
     * Developed by Compaq, Digital Equipment, IBM, Intel, Microsoft,
       NEC, and Northern Telecom
     * USB products under development by Digital Equipment (printer),  
       Intel (chipset), Microsoft (keyboard, mouse), NEC (monitor),
       Northern Telecom (PBX connection), IBM (Systems), Compaq  
       (Systems).
     * Open and royalty-free standard
 
  Specifications Summary
     
     * 12Mbps design with specific cost consideration for low cost
       peripherals
     * Supports up to 127 devices
     * Both isochronous and asynchronous data transfers
     * Up to 5 meters per cable segment
     * Built in power distribution for low power devices
     * Supports daisy chaining through a tiered star multidrop topology
 
jm.

_____________________________________________________________________________
Jonathan Mayer         http://www.crystal.com       jmayer at crystal.cirrus.com