For Portable Computer Users, Choice Is Easy

While the desktop computer market is filled with nearly indistinguishable PC clones and IBM originals, the available portables offer shoppers a choice. That is especially apparent when evaluating Zenith’s dandy new Z-181, that company’s second portable, and IBM’s first laptop, the PC Convertible, which is an intriguing combination of the good, the bad and the ugly.

There is a lot to like about the Zenith, starting with its exceptionally pleasing screen. The screen has the same nearly rectangular shape as the monochrome monitor of a standard desktop PC and is nearly as large--10 3/8 inches diagonally, compared to the desktop’s 11 inches. The backlit characters are iridescent blue against a light gray background and are produced by a new technology called “super-twisted liquid crystal display.” The results are undistorted images and less eye strain.

One need only to look at the screen of the IBM PC Convertible to appreciate the advantages. At 10 1/2 inches long and 3 5/8 inches deep, the IBM screen makes characters appear squat, and it turns pie charts into egg charts. The characters are dim gray against a gray-green background, offering little contrast. You need to have the light shining on the screen just right to see it. The backlit Zenith screen, of course, needs no external lighting.

Fortunately, the IBM screen is removable, so it can be gotten out of the way when you have the Convertible plugged into an external monitor, something you’ll want to do whenever possible. That’s a nice touch that Zenith ought to copy, because it also can be attached to desktop monitors.

Both portables come standard with dual, 3 1/2-inch disk drives, using the kind of disks that are encased in rigid plastic cases instead of the flimsy coated paper in which 5-inch diskettes come. The smaller disks store twice as much data--about 720,000 characters.

The Zenith comes with 640 kilobytes of electronic operating memory, otherwise known as random access memory, or RAM. The IBM can accommodate only 512K of RAM. Both computers can be equipped with an internal 1200-baud modem. Zenith’s matches the de facto Hayes standard for modem commands while IBM’s has its own non-standard command codes.

Both computers have built-in, rechargeable battery packs. The IBM’s is good for six to 10 hours, depending on drive use. Zenith says its batteries live up to five hours, reflecting the greater electrical needs of its backlit screen and extra memory.

Aside from the screens, the most dramatic difference between the two portables is how they are equipped. The Zenith comes standard with connectors for parallel and serial printers and an external color or monochrome monitor. IBM users need to buy extra modules that are snapped onto the back to enable parallel and serial printers and an external monitor to be attached.

What’s more, Zenith managed to package all its circuitry into roughly the same size case that IBM uses for just its basic system without the peripheral connectors. That means that feature for feature, the Zenith is not only cheaper, but lighter and smaller than the IBM. If you’ve got all the IBM adapters hooked up, in fact, the computer is too long to fit conveniently on most desks.

The Zenith and the basic Convertible each weigh about 12 pounds. The IBM even in its base configuration is longer than the Zenith because IBM chose to place its keyboard and screen across the narrow side of the rectangular case, while Zenith did the opposite. A big plus for the IBM is its sliding handle, which doubles as a wrist rest while typing. The Zenith badly needs a handle.

Since both computers are equipped with 3 1/2-inch disk drives, transferring existing programs and files from 5-inch disks is a problem. Zenith gives you two ways to handle that. One is a $100 package including a cable to connect its portable to a desktop PC and software for each machine. You also can buy an external 5-inch disk drive costing $399 to do the same thing without using a PC.

IBM requires you to use a PC for such transfers and sells an external 3 1/2-inch drive costing $395 to hook up to the PC.

An accessory that IBM offers and Zenith doesn’t is a thermal/ribbon dot matrix printer that you can attach to the back of the Convertible. But installing any of the IBM accessory modules is awkward and prone to be a knuckle buster.

A very nice feature of the Convertible, however, is the program that comes with it for writing short documents, scheduling, doing calculations and storing and dialing telephone numbers.

At a touch of a key, for instance, you can display all the blocks of time still available in your week for appointments. IBM chose to call this little gem “System/Apps.” Catchy, huh? (It won’t run on the Zenith.)

Another nice programming touch on the IBM is the ability to set up the Convertible so that it always returns to the point where you were in a program when you last turned if off.

The basic Zenith Z-181 carries a suggested retail price of $2,399. The modem is $399.

IBM’s basic PC Convertible with 512K lists for $2,385. The parallel/serial adapter costs $195, the printer runs $295, the modem is $450, an external monochrome monitor is $180, while a color monitor costs $400, and the adapter required to drive either monitor is $325.