Philips 201P User Manual

Contents

See rotation function.Trapezoid distortionSee Geometrical distortion.TTL signalA TTL (Transistor-transistor-logic) signal is a digital signal level for controlling the screen colors. With TTLdriving, the red, green and blue signals can only be switched on or off or provided with an intensity signal. ATTL-driven monitor can thus display a maximum of 64 colors. Video standards such as MDA, CGA and EGAare based on TTL level.RETURN TO TOP OF THE PAGEUUSB or Universal Serial BusA smart plug for PC peripherals. USB automatically determines resources (like driver software and busbandwidth) required by peripherals. USB makes necessary resources available without user intervention.USB eliminates "case angst" -- the fear of removing the computer case to install add-on peripherals.And USB also eliminates adjustment of complicated IRQ settings when installing new peripherals.lUSB does away with "port gridlock." Without USB, PCs are normally limited to one printer, two Comport devices (usually a mouse and modem), one Enhanced Parallel Port add-on (scanner or videocamera, for example) and a joystick. More and more peripherals for multimedia computers arrive onthe market every day. With USB, up to 127 devices can run simultaneously on a computer.lUSB permits "hot plug-in." There's no need to shut down, plug in, reboot and run set-up to installperipherals. And no need to go through the reverse process to unplug a device.lIn short, USB transforms today's "Plug-and-Pray" into true Plug-and-Play!HubA Universal Serial Bus device that provides additional connections to the Universal Serial Bus.Hubs are a key element in the plug-and-play architecture of USB. The Figure shows a typical hub. Hubsserve to simplify USB connectivity from the user's perspective and provide robustness at low cost andcomplexity.Hubs are wiring concentrators and enable the multiple attachment characteristics of USB. Attachment pointsare referred to as ports. Each hub converts a single attachment point into multiple attachment points. Thearchitecture supports concatenation of multiple hubs.The upstream port of a hub connects the hub towards the host. Each of the other downstream ports of a huballows connection to another hub or function. Hubs can detect, attach and detach at each downstream portand enable the distribution of power to downstream devices. Each downstream port can be individuallyenabled and configured at either full or low speed. The hub isolates low speed ports from full speedGlossaryfile:///D|/rita/LF2/LF2/LFa1/multi_manual/english/GLOSSARY/GLOSSARY.HTM (15 of 18) [8/29/2001 3:14:04 PM]