Glossary

●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.

●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 arrive on the market every day. With USB, up to 127 devices can run simultaneously on a computer.

●USB permits "hot plug-in." There's no need to shut down, plug in, reboot and run set-up to install peripherals. And no need to go through the reverse process to unplug a device.

In short, USB transforms today's "Plug-and-Pray" into true Plug-and-Play!

Hub

A 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. Hubs serve to simplify USB connectivity from the user's perspective and provide robustness at low cost and complexity.

Hubs are wiring concentrators and enable the multiple attachment characteristics of USB. Attachment points are referred to as ports. Each hub converts a single attachment point into multiple attachment points. The architecture 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 hub allows connection to another hub or function. Hubs can detect, attach and detach at each downstream port and enable the distribution of power to downstream devices. Each downstream port can be individually enabled and configured at either full or low speed. The hub isolates low speed ports from full speed signaling.

A hub consists of two portions: the Hub Controller and Hub Repeater. The repeater is a protocol- controlled switch between the upstream port and downstream ports. It also has hardware support for reset and suspend/resume signaling. The controller provides the interface registers to allow communication to/from the host. Hub specific status and control commands permit the host to configure a hub and to monitor and control its ports.

Device

A logical or physical entity that performs a function. The actual entity described depends on the context of the reference. At the lowest level, device may refer to a single hardware component, as in a memory device. At a higher level, it may refer to a collection of hardware components that perform a particular function, such as a Universal Serial Bus interface device. At an even higher level, device may refer to the function performed by an entity attached to the Universal Serial Bus; for example, a

file:///E/manual/english/109B/glossary/glossary.htm (19 of 22)2004-10-19 下午 01:44:20

Page 36 Page 38
Page 37
Image 37
Philips 109B user manual Hub
Page 36 Page 38

109B specifications

The Philips 109B is a notable product in the realm of computer monitors, particularly significant during its time for delivering a solid blend of functionality and affordability. Designed primarily for office and general computing use, the Philips 109B stands out as a reliable choice for users looking for a dependable display solution.

One of the key features of the Philips 109B is its display size. With a 19-inch screen, it strikes a balance between providing ample screen real estate for multitasking while still being compact enough to fit into various workspace setups. The screen resolution of 1280 x 1024 pixels ensures adequate clarity for text and graphics, making it suitable for everyday tasks like word processing, browsing, and even light graphic design.

The monitor utilizes CRT (Cathode Ray Tube) technology, a standard in earlier generations of monitors, which contributes to its deep color reproduction and high refresh rates. Users benefit from a refresh rate of up to 85Hz, significantly reducing flickering and providing a smoother visual experience, particularly during prolonged use.

In terms of ergonomics, the Philips 109B features a tilt-adjustable design, allowing users to customize the angle of the screen to their preference, thus enhancing comfort during extended viewing sessions. The monitor's build quality is robust, reflecting the durability often associated with Philips products, which is crucial in an office environment where reliability is paramount.

Connectivity is another strong point for the Philips 109B, equipped with connectors that support conventional VGA interfaces. This makes it compatible with a wide range of computers and peripherals, ensuring easy integration into existing setups without the need for additional adapters or converters.

Moreover, the monitor includes various color settings, allowing users to adjust their viewing experience according to their personal preferences, which can be particularly beneficial for graphic work or video editing where color accuracy is important.

Overall, the Philips 109B exemplifies a practical, user-friendly monitor that caters to a variety of computing needs. Its combination of size, resolution, ergonomic features, and solid build quality makes it a commendable choice for users seeking a functional monitor without unnecessary frills. While newer technologies have emerged since its popularity, the Philips 109B remains a testament to the reliable design and engineering that Philips is known for.
Top Page Image Contents