Despite all the references to the "untapped" market for computers in the home, manufacturers and retailers are having a tough time cashing in on this potential bonanza.

Market researchers can't agree on the right mix of computer hardware, software, features and price to attract buyers to machines for home use.

Personal computers have begun to find their way into the household: About 20 million homes now include some type of PC, according to market research firm Dataquest Inc.

Most of those computers were purchased, however, to serve as extensions of the workplace and really are intended for business applications. The number also includes many "computers" that are actually machines for playing video games.

Although millions of homes contain PCs, more than 90 million American homes do not. As the nation's offices, plants, shops and schools have become increasingly saturated by PCs, manufacturers have been eyeing those households as an important source of future growth.

Toward that end, two large PC makers recently launched campaigns aimed at the elusive home market. International Business Machines Corp. put forth its latest vision of the ideal computer for the home with the introduction of the PS/1 line, while Tandy Corp., which operates 7,000 Radio Shack stores, unveiled its competing vision, the 1000 RL series. Both companies are promoting their home computers as "easy to use."

In this case, IBM and Tandy are trying to say that their machines can be set up in a matter of minutes by people who don't know much about PCs. They also are trying to say that their machines include software for performing simple household tasks.

It's not clear, however, that such an approach addresses the fundamental obstacles that have kept PCs from becoming as common in the home as televisions, stereos and VCRs.

Tens of millions of people have become adept in the use of PCs through their experience on the job. Many of these people are perfectly comfortable with the complexity of computers. For them, the machines already are easy to use.

Yet, they do not choose to use computers at home for performing such tasks as balancing the checkbook, filing or recalculating recipes, maintaining an inventory of possessions or keeping a Christmas card list -- all functions touted by Tandy in its announcement.

A computer writer who wrote a book of advice on a popular money-management program used the software to keep track of his finances but gave up on it in a matter of weeks. For him, the hardware and software were easy to use, but the old noncomputerized methods were easier.

Most people -- even very accomplished computer users -- consider a general purpose, desktop machine to be overkill for maintaining a checkbook or performing similar tasks. The new "home computers" are unlikely to change the situation.

Compared with the check registers that banks provide to their account holders, a PC is a Rube Goldberg contraption. Try to put the computer, instead of the checkbook, in your pocket and take it to the supermarket to pay for groceries.

At the same time, computerization in the business world has had the effect of undercutting some of the potential applications for home computers. Financial institutions, for example, have tried to simplify the process of balancing the checkbook by using computers to provide customers with better organized and much more detailed statements.

Nevertheless, several developments in computer technology may help create more of a market for home units. Portability almost certainly will help. The advent of inexpensive notebook or "palm-top" computers will save space in the home and increase their convenience.