Sony has made a major marketing effort for its line of “VAIO” notebook computers and is now featuring the slim and lightweight 505G, a 200-megahertz Pentium system that the company clearly thought could dominate the market for budget sub-notebook computers. But with its A-500 Actius, Sharp has come out with a model so superior that it is difficult to imagine anyone buying the Sony who has seen the Sharp. Both now retail for $1,999.

The most striking difference is the screen. Sony’s 10.4-inch active-matrix display is fine, but the Sharp’s 11.3-inch diagonal screen is among the brightest and most richly colored laptop displays we’ve ever seen. In fact, it is one of the most vivid displays of any kind we’ve seen. The brightness of the screen goes a long way to make up for the fact that the screen is so much smaller than those of desktop models.

Indeed, the unit’s overall dimensions are smaller than a typical magazine, and with its silver-colored magnesium case, it is a sleek-looking device that attracts attention even before you turn it on. It looks like something out of the pages of a Sharper Image catalog.

The Sharp has a 233-megahertz Pentium processor, 64 megabytes of memory (that’s all it will accommodate), a 3.2-gigabyte hard disk and a built-in 56K v. 90 modem. Unlike many PC-card modems, this one requires no special cabling. You just plug the phone line into a jack on the side of the computer. The Sony VAIO 505G has only a 200-megahertz processor, 32 megabytes of memory and a 2.2-gigabyte hard disk.

The Sharp comes with an outboard floppy disk drive that also contains the parallel printer port and the serial port. This means you must carry the floppy drive with you if you are planning to do any printing, or if you plan to hook up any serial devices, such as a null-modem cable to connect the system to a desktop unit for file transfer.

The floppy drive attaches to the side of the A-500 via a thick cable that is too short to tuck into the slot on the underside of the drive case, but not long enough to give you much flexibility as to where you place it on the desk when you are working. This can be awkward if you are working in a narrow space, such as on an airplane tray table. It’s a drawback.

There is no CD-ROM drive, and you will need one since so much software now comes on CD. Sharp makes a portable outboard CD-ROM drive that retails for about $400, but it will tie up the computer’s single PC-card slot. Parallel port CD-ROM drives, such as the Backpack Bantam, sell for about $300, weigh about a pound and a half, and do not use the card slot.

The system has a built-in touchpad to control the mouse pointer. It is placed, as most such devices are, near the base of the unit just below the keyboard. It is easy enough to move the pointer around with your forefinger, but hitting the two buttons just below it requires a little more effort than it should and may make you long for your desk at home or hotel where you can hook up a regular mouse. There is a PS/2 port on the side of the computer for just that.

There are built-in microphone and outboard speaker connections on the side as well, but the built-in speaker works well enough that you may not need to hook up outboard speakers, even when you’re sitting at your home or office desk. There is a volume control on the side of the unit.

The keyboard is far from full-size and takes some adjustment for a touch-typist. But, unlike the keyboards on handheld PCs, it is large enough that you can touch-type on the A-500. The function keys are tiny and the layout of the arrow keys (in an “L”) may confound you at first. You have to press a special “Fn” shift key to use the Page-up, Page-down, Home and End keys, which are the arrow keys when the Fn key is not pressed.

Battery life is estimated at two and a half hours with the built-in lithium-ion battery. But users should expect this to vary, depending on how much the hard drive is in use, and how much of a workout the modem gets while the computer is on battery power.

The A-500 comes with Windows 98 preinstalled, Traveling Software’s Laplink for file exchange, a graphic presentation package called Mind Path Presentation F/X, and that’s all.

T.R. Reid is London bureau chief of the Washington Post. Brit Hume is managing editor of Fox News in Washington. You can reach them in care of the Washington Post Writers Group, 1150 15th St., Washington D.C. 20071-9200, or you can e-mail T.R. Reid at [email protected] and Brit Hume at [email protected].