PICKING RIGHT NOTEBOOK TAKES CARE.

Byline: Yardena Arar Daily News Staff Writer

Larry Mondry, executive vice president of merchandising for CompUSA, said he gives prospective notebook buyers the same advice he gives to anybody shopping for desktop systems.

"Know what you're using it for before you buy it, and be honest about it," Mondry said. "People don't want to say they're going to use it to play games on airplanes, but that's what they do."

Factors to consider - aside from the usual RAM, hard drive and processor specifications you'd look at in buying a desktop - include weight, screen size and multimedia components.

Decide whether you'll want floppy or CD-ROM drives built in, which add two to three pounds of weight to the 4-6 pound weight of the typical laptop, or whether you're content with external versions that can be plugged in as needed. Some models allow you to swap a CD-ROM and a floppy drive.

Laptops come with three basic types of pointing devices: a track ball, a mini-joystick or a touch pad. Like keyboards, which vary in size and feel, pointing devices are a matter of personal preference.

If you're going to be Net surfing on the road, consider investing in a 28.8-kilobaud modem, either an internal one or a PC card, the new term for those credit-card-size plug-ins that used to be called PCMCIA cards. These cards are categorized as types 1-4, with 4 being the thickest. The typical laptop can accept either two type 2s or one type 3 card. Most consumers use type 2 fax-modem or Ethernet (network) cards.

Newer, more expensive models have larger screens - the 10-inch screens that used to be hot have given way to 11- and even 12-inch screens - and the price differential between active-matrix and dual scan has dropped from as much as $1,000 to $200 to $300.

The price differential between laptops and desktops may not be as enormous as it often looks at first glance. "One thing you have to consider is that when you see prices for desktop systems, they often don't include monitors," said Rich Malloy, editor in chief of Mobile Computing magazine.

In general, expect to pay $1,000 to $1,500 more for a laptop than for a desktop with equivalent features. That may seem like a lot, Malloy said, "but when you get a desktop computer you're getting only a third of a computer. You can only use it eight hours a day, whereas when you have a laptop you can carry that with you all the time and they're always available.

"With portable computers, you can do your homework while watching TV. You can't do that on a desktop."