A colorful "Welcome!" flashes on the video screen attached to the handle of the supermarket cart. Enticing images of tomatoes, corn and lettuce appear as the shopper wheels into the produce department.

Within seconds, the picture changes to a list of weekly specials: "red leaf lettuce 69 , zucchini 39

lb., avocados 77 , strawberries $1.37 pint." Recipes, notes the screen, are available in the produce department.

Entering the cereal aisle, another list of weekly specials appears. As the cart passes in front of Cookie Crisp, a sequential ad pops on the screen: "Kids love the chocolate chip taste! You'll love: no cholesterol, no tropical oils, 4 wholesome grains, 9 vitamins and minerals."

Meanwhile, an electronic sign over the deli aisle scrolls a chain of messages, among them "Oscar Mayer franks are good for you." Throughout the store, soothing music from a satellite radio system is being broadcast interspersed with ads reminding shoppers that Tide is on sale on aisle 8.

In the cookie aisle, an impish voice beckons from the shelf of graham crackers: "Whoa! Stop the cart! Over here, Teddy Grahams, America's favorite graham snack in the unbearably delicious honey, cinnamon, chocolate and new vanilla flavors." The voice is coming from a small speaker that also dispenses 25-cents-off coupons.

Over in the pantyhose section a woman ponders size and style. She steps up to a large computer screen and answers several questions about height, weight, shoe style (open or closed toe) and wearing occasion (primarily standing, sitting, walking, etc.). The computer recommends the appropriate size and style -- and goes on to suggest that she buy several pairs.

As shoppers queue up in the long checkout lines, they watch the latest news, sports, weather and commercials, of course, on TVs strategically placed above the gum and candy racks.

All the while, a computer is operating the checkout stand. As the shopper does the scanning, a picture of the product and its price flashes on a screen. A cashier stands close by to accept the money.

The store's computers even reach into the shopper's home. A few days later, a thank-you letter arrives, full of rebates or coupons. The coupons include one for peanut butter to go with the just-purchased jar of strawberry jam and a special discount for fresh seafood that politely encourages the customer to switch from frozen seafood to fresh fish, which just happens to be more profitable.

Not all of these whiz-bang computer creations can be found in a single supermarket -- at least not yet. But, each piece of this automated adventure is being tested, or is about to be, in major supermarket chains across the country.

"It seems like we're testing one form or another of every new technology," says Paul Bernish, spokesman for Kroger Co. "We're interested in looking at things that would enhance the shopping experience. Whether it's to entertain or help customers do shopping more quickly and conveniently, we are willing to look at things that might help. We're probably looking at everything at this point."

For supermarkets, entertaining electronic gadgetry offers the hope of higher profits -- not only by luring more customers but also by capturing a portion of the advertising dollars food manufacturers traditionally spend on newspaper and television ads.

For shoppers, however, these computer commercials could create such an overload of information that the supermarket would, in the words of one food-industry official, soon becomes the "store from hell."

"The bad news is that there will be a lot of clutter for a while," acknowledges Wayne LoCurto, president of ActMedia Inc., which as the nation's largest in-store marketing firm is testing several electronic marketing devices. However, LoCurto quickly adds, "most of {the clutter} will go away ... . The retailer will draw the line and many of these products will disappear."

In fact, many already have come and gone -- and come again. Chief among these are complicated electronic store directories, coupon-dispensing kiosks and video programs requiring several minutes of a shopper's attention. "For people trying to rush around and fill a shopping cart, these were asking an awful lot," notes Gary Arlen, president of Arlen Communications Inc., a consulting firm that specializes in electronic marketing.

Continuously talking promotions also have presented problems, notes Michael Rourke, vice president of communications and corporate affairs for the Great Atlantic & Pacific Tea Co. "If the TV monitor is continuously blaring information or talking, we often get complaints," he says.

Still, the supermarkets keep experimenting.

In the Washington area, Giant Food Inc. is starting to install electronic signs with scrolling messages over the aisles. The signs should be in all Giants early next year. Later this year, Giant plans to experiment with the video shopping cart in one yet-to-be-selected store. "Initially I thought {the shopping cart} was just a gimmicky offering," says Bob Schoening, Giant's senior vice president for data processing. But the company has come to like the cart's detailed on-the-spot store directory of 1,000 items, which would help customers frustrated by cursory overhead directory signs.

Additionally, in six of its stores, Giant has been quietly testing a frequent shoppers program under which customers are rewarded for buying certain advertised specials. The reward, mailed to the home every three months, is a voucher that can be redeemed at the store for cash.

Meanwhile, Safeway Stores Inc., which has been broadcasting satellite music and commercials in local stores for several years, is within weeks of installing automated check-out stands, dubbed CheckRobot, in three Washington-area stores. Safeway is the first chain to sign up for CheckRobot in more than one store.

Wiring the supermarket "will be the positioning issue in the '90s," says Jim Vanderholm, president of Paradigm Solutions, an electronic marketing software company. As the stores become more competitive, they "will have to look for every strategic edge and opportunity they can."

In the process, the supermarket will become an increasingly active advertising arena as manufacturers seek attention at the precise point where shoppers are about to make their purchases.

Up until the early 1980s, there was very little advertising in the supermarket, other than the obvious panorama of attention-grabbing packaging. Manufacturers preferred newspapers and television to get across their message. Slowly, however, commercials started appearing in the stores, first with glossy pictures attached to the backs of the shopping carts of Pepsi, Chips Ahoy, Luvs and other brand-name products.

Today, in-store advertising has grown into a $250 million business, and "there are projections for the industry to boom to a $1-billion business by 1995," says ActMedia's LoCurto.

Behind the growth is the increasing diversification of America's once homogeneous population -- a population that Kraft, for example, once reached easily by sponsoring a celebrated television theater on Wednesday nights.

"You now have to be on several radio stations, in neighborhood mailers and flyers, on several TV stations and in several newspapers," says Timothy Hammonds, senior vice president for research and education of the Food Marketing Institute. "But there is one place where you can reach consumers" with a single advertisement and "that's in the grocery store because you still have to go to the store to shop."

The supermarket is even more attractive as an advertising medium because increasingly purchasing decisions are being made at the store. As Hammonds notes, "with the pressure of two-income families, time is getting to be a very scarce commodity so people are making more and more decisions in the store instead of coming to the store with a very detailed list."

So, LoCurto says, "there is no better place to influence {shoppers} than at the point of purchase -- just as they are about to reach for that tube of toothpaste."

That's the premise behind many of the computerized gadgets being tested, including the automatic coupon-dispensing machines attached to the shelves. Two different versions are being offered, one by ActMedia, the other by a newcomer to the in-store marketing business, Top Image Resources Co. The latter's machine talks; the former's uses two flashing lights on each side to attract attention.

"This is the ultimate in couponing," explains LoCurto, who notes that less than 3 percent of the 257 billion coupons issued annually are ever redeemed. "What better place is there to issue coupons to consumers than right in the category they are about to purchase."

For supermarkets, this electronic entertainment offers the opportunity to make shopping less onerous, more fun -- and ultimately, more profitable.

Entertainment is precisely what Checkout Channel, a joint venture of ActMedia and Turner Broadcasting System, is trying to provide. The supermarket network -- which will begin testing this month in five major chains including Kroger and A&P -- will broadcast live news, weather, sports and ads to stores via satellite. The broadcasts will be shown near the checkout and the sound will be triggered by the approach of a customer.

"One of the most dominating complaints is how long it takes to check out," says Kroger's Bernish. "So, while they are checking out, if we can provide something useful, some information or entertainment, we might as well take a look at it." Besides, Bernish notes, Checkout Channel "doesn't cost any money to Kroger." In fact, like all electronic advertising campaigns, Checkout Channel will pay for the privilege of being in the store.

In total, the electronic experiments provide "not a great deal of revenue, but every little bit helps in this low margin business where profits are a penny," says A&P's Rourke, on every dollar of goods sold.

Yet, supermarket officials say that even more valuable than the added revenue is the detailed customer information many of these electronic marketing programs will provide. That is particularly the case with the frequent shopper programs -- "the green stamps of '90s," according to Vanderholm.

Much like the airlines' frequent flyer campaigns, the frequent shopper programs give rebates, discounts and coupons to customers who have signed up.

All the customer has to do is present an identification card when shopping. For the store, however, that ID card is critical. It can provide a host of details on a shopper's habits -- details that will enable chains to tailor each store more precisely to the needs of each neighborhood. At the same time, the store can send the shopper personalized promotions: coupons for dog food to pet owners, discounts on diapers to baby food buyers, rewards to frequent shoppers and discounts as incentives to infrequent ones.

"Electronic marketing gives us the opportunity to establish a dialogue with our customers that has been historically missing since we got out of the corner grocer environment of the pre-1940s," says Dennet Withington, vice president for management information systems of Price Chopper, a chain of 76 stores in the northeast. Computers will enable the supermarket to know all about "Mrs. Schultz down the street," says Withington: where she shops, when she shops, how often she shops, what she buys and if she stops shopping.

"Whether it is a frequent shopper type program, electronic coupons or electronic discounts -- all will come and go," says Withington, "the goal is to establish a dialogue."