Imitation in the personal computer business is more than the highest form of flattery. It's also highly profitable.

The proof is here, where Columbia Data Products Inc., has taken in $10 million on a new personal computer that is what Columbia officials call "an enhanced version" of International Business Machines' popular IBM-PC.

Columbia's strategy is to sell its Multi-Personal Computer (MPC) systems at prices well below comparable component mixes sold by IBM. And the strategy is working.

The MPC was introduced last June at the National Computer Conference in Houston. Columbia's officials left the conference with $10 million worth of international distribution contracts with 200 dealers in Europe and South America.

In the worldwide personal computer industry currently valued at $6.1 billion, $10 million is akin to pocket change. But it's a lot of money for a tiny, privately held company with 150 employes and $15 million overall in projected annual sales for 1982.

"If we can get 1 or 2 percent of the worldwide market, we would be extremely successful," said William Diaz, 40, Columbia's president.

With the MPC, a personal computer designed for use by engineers, accountants, writers and other professionals, Diaz believes that objective is attainable.

"We have carved out a niche in a mass market. We're not going up against IBM. We're just trying to piggyback on them a little," Diaz said.

Actually, Columbia simply has taken advantage of IBM's generosity, or folly, depending on one's viewpoint.

IBM introduced its IBM-PC on Aug. 12, 1981. The introduction was "open," meaning the giant computer company unveiled the schematics for its new product, as well as the product itself. In short, IBM told everybody how its new computer worked.

"We knew that, in the short term, we couldn't supply all of the products" that could be used in conjunction with the IBM-PC, an IBM official said. "We wanted to make the IBM-PC both accessible and beneficial to as broad a range of people as possible," said the official, who requested anonymity.

But IBM's tack was not totally altruistic. The company was depending on its name to generate sales in an increasingly confused market where strong name recogniton was needed to cut through the fog. The plan worked. In a little more than a year, IBM took as much as 10 percent of the worldwide market.

Entrepreneurs using the IBM-PC's schematics started churning out "IBM-compatible" software, such as computer programs, and hardware, such as printers. Today, there are 1,250 companies making "IBM-compatible" products. The market for these products, in turn, is helping to push sales of the computer itself.

Columbia is also in the "IBM-compatible" business. But the company used the IBM-PC shematics to come up with what Columbia's growing list of customers apparently regard as a better idea.

"We already were working on a product" when the IBM-PC was introduced, said Frank Conte, Columbia's vice president of engineering. He said Columbia had done the necessary research on a personal computer designed primarily for professional use, rather than general home use.

"We cannot deny that the IBM box the microprocessor that is the heart of the computer is a good box. We looked at their schematics and decided to make slight modifications in our own plans," Conte said.

Those "modifications" yielded a Columbia microprocessor capable of serving eight users simultaneously, compared with the single-user capability of the IBM-PC. At prices ranging from $2,995 to $5,400, the MPC's are $500 to $550 below prices on comparable IBM models, Columbia's officials say.

The Columbia group added another twist: they are advertising the computer itself as "IBM-compatible." For example, one promotion says: "Columbia's MPC can use software and hardware originally intended for the IBM Personal Computer . . . while offering a substantial price advantage and upward expansion capabilities."

IBM officials declined comment on Columbia's claims.

Meanwhile, Columbia's leaders say they expect domestic sales of MPC's to reach 2,000 a month by mid-1983, and 3,500 a month by the end of next year. The company also expects international sales of 4,000 units in 1983, said John A. White, Columbia's vice president of sales and marketing

Said Diaz, Columbia's founder and sole stockholder: "We're going to deliver products and services that large companies can't deliver, or don't want to deliver because of cost-effectiveness.

"It's not a matter of small companies like ours going against the big companies like IBM. We want to serve a special market. As long as we continue to invest our resources in the engineering and software areas, the sky is the limit.

"You're looking at a phenomenon here," Diaz said." "The sheer size of this market is phenomenal.