The Macintosh Classic, least expensive of the three new Macintosh models, gives the Mac what it has never had before: an up-to-date entry in the low end of the personal-computer market. It comes as IBM is making a renewed effort to win over home and small-business users with its PS/1. They are comparably priced and the competition between them will be interesting.

First, the Classic. At $1,499 for a two-megabyte system with a 40-megabyte hard disk, it is an outstanding value. It replaces both the Mac Plus and the Mac SE. With a 7.8 megahertz, Motorola 68000 microprocessor, it runs only marginally faster than the Mac Plus, just a bit slower than the SE. But in appearance and overall design, it is closer to the SE. This is a handsome system.

It is not the computer you'd choose for heavy number crunching or intensive graphics work. But for word processing and light database work, for example, it is plenty powerful. It should be especially popular with college students, who will appreciate the compact design. Space is scarce on dormitory desks. And Mac software such as Microsoft Word includes such advanced functions as footnotes, which academic papers frequently require.

Finally, there's the Mac's operating system. Designed from the ground up as a graphical environment, relying on a mouse and on-screen pointer, it is easy to learn and fun to use. All software for the Mac tends to look alike, so that if you know one program, you can quickly find your way around in another.

Ease of operation has made the Mac famous, but for years its popularity has suffered because a Mac always cost more than an IBM or compatible of comparable power. The Classic goes a long way to eliminate that objection, as the $1,999 list price for a similarly equipped IBM PS/1 demonstrates.

The big difference between the $1,499 Mac Classic and the $1,999 PS/1 is that the IBM is a high-resolution color system while the Mac is black and white. This gives the PS/1 an edge for computer games. The Mac, however, has two megabytes of memory, twice what the PS/1 offers, and a 40 megabyte hard disk, compared with the PS/1's 30. Both use 16-bit microprocessors. The IBM's 10 megahertz Intel 80286 is slightly faster.

The IBM also comes with a built-in 2400-baud modem, a subscription to the Prodigy on-line service and a copy of Microsoft Works. This is a smoothly integrated set of business programs, including a word processor, database, spreadsheet and modem-communications program. None of the individual parts of Works is as powerful as the industrial-strength programs used in many offices, but it is well-designed and works with or without a mouse. It is the only software many small businesses or home offices will ever need.

The trade press has labeled the PS/1 underpowered and overpriced, and it is true that more-powerful PC compatible computers can be had for less. But the power-price ratio is not what IBM hopes will sell the PS/1. The PS/1 was designed to be what the Mac has always been -- simple to use.

So instead of a complicated set-up process involving a lot of plugs and cables with arcane names, IBM has made setting up a PS/1 much like installing a basic appliance. You hook up a few wires, turn on the system and you're on your way. It has one of the shortest user manuals ever and its set-up booklet is little more than a folder.

Instead of a nearly blank screen with a cryptic "DOS" prompt at the top, the PS/1 gives you a colorful screen split into four quadrants. You choose which one you want with a mouse. One provides information about your system, or the broader range of information available when you connect to the Prodigy on-line service.

Another section of the screen, called "Your Software," takes you into a simple graphical operating environment from which you can run the software that comes with the computer, or programs you have added yourself. There is nothing fancy about this. It uses a file cabinet analogy, with folders representing programs.

Another section takes you into MS-DOS, the dread PC operating system. This brings you to a crude example of what is called a DOS shell, a list of DOS functions you can pick by placing the cursor over your choice and hitting a key. You can get to DOS through the "Your Software" file cabinet as well, and you can select which DOS function you want to use with the mouse.

It's a hard choice between these two systems. With IBMs prevalent in offices, the PS/1 will be attractive to many wishing to bring work home. But the Mac, with its sleek styling and famed ease of use, will attract many new users. The safest move is to try software for both and buy the one that runs the programs you prefer.

Brit Hume is a contributor to the Washington Post Writers Group. He is chief ABC News White House correspondent and the founding editor of a computer newsletter.