Laptops, notebooks, hand-held computers and personal digital assistants -- the exact definition of each has blurred as their numbers and features have expanded, but one thing is common to all: they're meant to travel.

MetroBook DT

Today's "freedom machines" range from electronic schedule and address books to portable computers with most of the features of the best desktop machines. More powerful chips, digital transmission modes, higher bandwidth, cellular phones and other wireless communication technologies have unplugged computers and set them free, rolling down the nation's highways and sailing through its skies.

Notebook sales grew 20 percent in 1997. In this era of great expectations, people want access to their bank accounts, airline reservations and the latest news reports 24 hours a day. In the midst of innovation and expectation, state and local government are struggling to catch up.

Types Great, Less Filling

There are two general approaches to notebook design. One emphasizes light weight and limited function for those who don't need the power of a complete desktop system. Many lightweight systems include basic e-mail, calendar functions, Internet access, word processing and spreadsheets. Peripherals such as CD-ROMs and storage drives can be attached as needed. One drawback is that keyboards and monitors are usually smaller than standard.

The other approach is the desktop replacement, intended to provide desktop computing in a somewhat larger and heavier notebook. If users run large applications, give presentations, spend long hours in front of the display or want a comfortable keyboard, these notebooks are ideal. However, the larger size and need for

bigger batteries make them more cumbersome to carry through airports or to off-site meetings.

Over the past year, notebook computers have taken some interesting turns. Some got thinner, but others got thicker. Notebooks are offering faster processors, better screens, more features and lower prices. It appears that portable PCs are finally finding their way into mainstream computing.

Accelerated Processors

In 1997, processor speed increased from 166MHz to 266MHz. Tillamook, Intel's latest family of energy-efficient, mobile Pentium MMX processors, is manufactured using a .25 micron process, which reduces cost and power consumption significantly over the older .35 micron processors. An even faster and cheaper 0.18 micron processor is expected soon.

Three of the newest chips are a 3.4 watt, 200MHz model; a 3.9 watt, 233MHz model; and a 5.3 watt, 266MHz model. Tillamook introduced Intel's new processor-mounting technology, called IMM (Intel Mobile Module).

Intel's 233MHz, 266MHz and 300MHz mobile Pentium II processors -- called Deschutes -- have began to appear in many newer notebooks.

A less-expensive CPU is clearly on the horizon for low-cost mobile computers. Next year, Intel expects to have Pentium II processors in notebooks that sell for less than $1,500.

AMD has also reduced its K6 processor to .25 microns and is making its CPUs more attractive to mobile manufacturers.

More Storage

When it comes to computers, there's never enough storage or RAM. Last year, notebook hard-drive capacities increased from 2GB to 8GB, and 4GB of storage is now mainstream.

Increased hard-drive storage and RAM really help system performance. Intensive word processing, spreadsheets, database management and browsers require lots of memory. Windows 95 and 98 need at least 16MB of RAM just to run, but they run much better with 32MB. That's one reason notebook manufacturers increased RAM from 8MB to 32MB.

Even floppies are feeling the acceleration. The 3.5-inch 1.44MB diskette drive is becoming obsolete, and high-capacity hard drives such as CD-ROM, and peripherals such as Iomega Zip and Syquest SyJet drives, are giving users large amounts of space for handling hungry programs.

Pick a Card, Any Card

4150 Compaq Armada

Today, almost all notebooks employ PC Card slots. PC Cards can be added easily to expand or upgrade notebooks. Last year,