Buying a house can be a long, tedious process, but computer technology is making it easier - and more fun - in some cities.

In Boston, for example, a buyer can sit with a real estate agent at a computer terminal and look at towns throughout Massachusetts. When he finds one he likes, he can start looking at houses there - room by room - right on the high-density, color screen.This service is offered by HomeView Realty Centers, which during its first 20 months of operation attracted more than 10,000 people to its three Boston-area offices.

In HomeView's computers are color pictures of all the houses listed by brokers in Massachusetts - about 22,000 at any one time. "It's the largest color picture data base in the world," said Nancy Moss of Schneider & Associates, the company's public relations firm.

Here's how the system works:

You want to buy a house but aren't sure exactly where you want to live or what kind of house you want. Entering a HomeView office, you're greeted by a real estate agent at a computer terminal.

You name two or three towns you think you might like, and the agent calls each one up on the screen. You can actually see the streets, the library, the town hall and the schools. With the flick of a button, you also can get scads of demographic information on the town, its school system, taxes, commuting times and other points of interest.

Knowing more about each town but still undecided, you move on to a house search.

"You characterize the preferences that you want, your price range, then a whole host of different criteria," Moss says.

Among the choices - type of house (colonial, Cape Cod, ranch, modern), number of bedrooms, attached garage, fireplace, deck, master bath, air conditioning, heating preference and a host of others.

For each option, you can say it's a "must have" or just a "would like to have." And if you're overwhelmed by all the choices, the real estate agent will narrow things down with your guidance.

Once you've listed your requirements, a menu screen appears with photos of the houses that meet your needs.

"Touch the one you want to look at first," Moss said. "That house will fill the whole screen. If you like it, you touch it again and it will give you a menu of the living areas that you can tour."

You can walk through each room and all the surrounding grounds, even getting a view of the street as seen from the house.

For each house you want to see, you get a color catalog and HomeView sets up an appointment for you with the listing broker.

There's no extra charge for the HomeView service.