Portable computing glossary. (Compute's Getting Started with Portable Computing) (Glossary)
by David English

active matrix. A type of LCD display that uses a transistor--or three transistors in the case of a color LCD--to drive each pixe. The brightness, contrast, and refresh rate for active-matrix LCD screens is generally on a par with standard CRT (Cathode-Ray Tube) monitors. See also LCD and passive-matrix.

docking station. Also known as expansion chassis. An external box that allows a laptop computer to add a combination of expansion slots and drive bays.

gray scale. The progressive series of grays that a device can produce, ranging from black through white. On a portable computer, the quality of the gray scale is dependent on the video controller (usually CGA, EGA, or VGA) and video display (usually 16, 32, or 64 grayscale LCD).

laptop computer. A portable computer, usually able to operate from either batteries or AC power, that offers most or all of the functionality of a desktop computer. Laptop computers are generally considered to be portable computers that weigh 8 to 15 pounds, but the term is also used generically to refer to any portable computer, including a notebook computer, that weighs less than about 18 pounds.

LCD. Short for Liquid Crystal Display. A type of computer display that sandwiches a liquid compound between two transparent electrodes. LCD screens are found in the vast majority of laptop computers because they consume less power than a standard CRT monitor.

notebook computer. A lighter and thinner version of a laptop, usually weighing less than eight pounds.

palmtop computer. Also known as hand-held computer. A computer small enough to be held in one hand, usually weighing less than two pounds.

passive matrix. The type of LCD display found on most currently available laptop and notebook computers. Passive-matrix LCD screens are less expensive and have less brightness, less contrast, and a slower refresh rate than active-matrix LCD screens. See also LCD and active matrix.

submarining. Slang term for the disappearance and reappearance of the mouse cursor as it moves across an LCD screen.

transportable computer. Also known as luggable computer or lunch-box computer. A portable computer than weighs from 15 to 35 pounds and required AC power. Most transportables have standard CRT monitors built-in.