2.4 Portables
2.4.1 Why portables can be portable
Portables incorporate the system unit, input unit, and output unit into a single, lightweight package, which unlike the towers or desktops, can be carried around by the user. They are also called notebook computers, palmtops or Personal Digital Assistant (PDA), depending on their size and what they can do. The focus in this chapter is laptops and notebook computers, but the issues discussed are common to all portables.

Producing portable computers has not been without its problems. Early attempts at developing a portable computer produced heavy systems with short operating times between battery recharges. With the advancements in technology, particularly in IC (integrated circuits) and peripheral component designs, the portable now competes with desktop and tower systems in speed, power, and number of features. A typical notebook computer, such as the one depicted in the figure, features a video display that is larger than those typically associated with the older PC-AT machines, a hard drive with a capacity in the tens of gigabytes, and CD-ROM/DVD drives. As technology improves, notebook components are designed to use less and less power (via rechargeable batteries), but are at the same time more rugged. These concepts are explored further in the sections that follow.