of removing the computer case to install circuit board cards -- that often requires adjustment of
complicated IRQ settings -- for add-on peripherals. USB does away with "port gridlock." Without USB,
PCs are normally limited to one printer, two Com port devices (usually a mouse and modem), one
Enhanced Parallel Port add-on (scanner or video camera, for example), and a joystick. More and more
peripherals for multimedia computers come on the market every day. With USB, up to 127 devices can
run simultaneously on one computer. USB permits "hot plug-in." No need to shut down, plug in, reboot
and run set up to install peripherals. No need to go through the reverse process to unplug a device.
Bottom line: USB transforms today's "Plug-and-Pray" into true Plug-and-Play!
Please refer to glossary for more information about USB.
Q: What is a USB hub ?
A: A USB hub provides additional connections to the Universal Serial Bus. A hub's upstream port
connects a hub to the host, usually a PC. Multiple downstream ports in a hub allows connection to
another hub or device, such as a USB keyboard, camera or printer.
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LCD Panel Technology
Q:
What is a Liquid Crystal Display?
A: A Liquid Crystal Display (LCD) is an optical device that is commonly used to display ASCII
characters and images on digital items such as watches, calculators, portable game consoles, etc. LCD
is the technology used for displays in notebooks and other small computers. Like light-emitting diode and
gas-plasma technologies, LCD allows displays to be much thinner than cathode ray tube (CRT)
technology. LCD consumes much less power than LED and gas-displays because it works on the
principle of blocking light rather than emitting it.
Q:
What differentiates passive matrix LCDs from active matrix LCDs?
A: An LCD is made with either a passive matrix or an active matrix display grid. An active matrix has a
transistor located at each pixel intersection, requiring less current to control the luminance of a pixel. For
this reason, the current in an active matrix display can be switched on and off more frequently, improving
the screen refresh time (your mouse pointer will appear to move more smoothly across the screen, for
example). The passive matrix LCD has a grid of conductors with pixels located at each intersection in
the grid.
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