It sounds like a deep philosophical question: What is the fundamental nature of a computer?

Locke and Hobbes aside, most people would include "keyboard," "hard disk" and "dedicated monitor" somewhere in their answer. And in the 1990s, that's what we expect a computer to look like.

Fifteen years ago, however, the idea of the computer was very different. IBM's original Personal Computer was strictly a business tool. Expensive and terribly overpowered--with a whopping 64 kilobytes of RAM--few people needed the flexibility it offered.

Instead, many of today's undergraduates cut their computer teeth on systems like the Atari 800 and Commodore 64 and Coleco Adam. They only cost a few hundred dollars and plugged right into your television set. And unlike IBM's original PC, they were colorful and easy to use.

These early machines had a lot in common with pet rocks, however. They mostly just sat there. Unlike the ever-expandable IBM PC, you were limited in what you could do with them. Eventually, people got bored and bought more powerful machines--like the IBM PC and its clones.

While Atari and Commodore went out of style with parachute pants and the Bangles, however, the computer industry is about to go retro with the coming of the so-called "network computer."

Developed by industry giants like Apple, Sun and Oracle, the network computer--or NC--marks a return to the concept of scaled-back systems for home use.

The NC, which costs less than $500, plugs into your television set for you to use as a monitor. It probably won't include a hard drive either; instead, it will plug into your telephone line and connect you directly to the Internet.

And it certainly won't look like a computer. Like its predecessors, the NC is designed to blend into the home. Without the bulky peripherals of desktop machines, the NC is meant to be attractive to technophobics.

Supporters of the NC note that most people don't need all the power offered by a Pentium system for tasks like word processing and e-mail. The NC will be based around the "network-centric" model, in which the Internet is at the heart of computing.

Instead of storing files on a hard drive, the NC will save it on a secure server on the Internet. When you need to access it, the NC retrieves it. Large software programs like Microsoft Word would be replaced by efficient "applets" written in Java or another Internet programming language, and downloaded on a per-use basis.

Most students already use the network-centric model in their daily lives. Undergraduate e-mail is stored in a central disk array in the Science Center, and students use telnet and Eudora to retrieve new messages. The data, and much of the processing load, is handled by the network, not the PC on your desktop.

This means that most students also understand the fatal flaw in the NC model: the assumed reliability of the network itself. Students who use the Internet for Web browsing and e-mail can live with "Site Not Found" and "Mail Server Unavailable" errors most of the time.

But imagine if you had an important problem set or paper stored on a remote hard disk and needed to access it. If the network went down, your NC would cough politely and tell you to check back later.

Consumers have been wary about trusting credit card numbers to the Internet for online purchases. But NC proponents think users will gladly trust their important files and data to what is, at heart, an unreliable system. Chances are, they'll be in for a rude awakening.

Like home computers of old, the NC won't be as expandable as a desktop computer. It'll do a great job for surfing the Internet and light writing tasks. But chances are many users will soon outgrow these lightweights and buy a PC after all.

Look for NCs from several vendors to hit the market around Christmas 1996. But if you want to plug a computer into your television set, don't waste your money on one. I'd recommend you drag out your old Commodore 64 instead.

Kevin S. Davis is the Currier House User Assistant and HASCS's Networking Advanced Support Technician. His e-mail address is ksdavis@fas.harvard.edu.