After a marathon of negotiations so drawn out and labyrinthine that they resembled the pre-bout antics of a pair of Sumo wrestlers, I have just about reached tentative agreement on the sale of the Japanese rights to a new book of mine.

This will bring in a modest, but welcome, hunk of yen. The amount will be considerably more modest after my Tokyo agent, my New York agent, the Japanese Ministry of Finance, the Internal Revenue Service, and various local tax collectors each take their share. But there should still be enough left over to satisfy my yen for some new consumer goods.

The Japanese sale will help me buy a new car. What's much more exciting, though, (and much more relevant to this column) is that I'm also going to buy a new computer. I don't yet know which make or model I'm going to get, but I do know one thing for certain: I'm going to use my Japanese earnings to buy an American-made computer.

It's hardly a sacrifice. The best personal computers anywhere on earth are those designed and built right here at home. Americans invented the personal computer, and Americans developed it into a hugely successful new product.

But now the rest of the developed world -- in particular, Japan -- has launched a major effort to catch up in personal computers. And the brunt of that international marketing bonanza is going to be aimed at the world's largest market for personal computers, the U.S.A.

I heartily urge every American computer buyer to resist these foreign blandishments. We should stick to the home-grown stock for a variety of reasons, but there's one rationale that is preeminent: We Americans should buy American computers because they're American.

Clearly, if this simple-minded nationalism applied across the board, then I ought to urge you to buy American-made cars, American shoes, American wine, etc. Indeed, I urge you to do just that. Though this might have a devastating impact on the Volvo-driving, brie-nibbling Yuppie lifestyle many hold dear, Americans ought to buy American.

In the case of cars, this is not always an easy argument to make. I have always bought American cars on principle, but I often feel like a sucker for it. There's a breezy little Toyota that would exactly fill the bill for the new car I need now, but I won't even look at it. This is what is known as blind chauvinism. Japanese consumers practice it like mad, which is one of the reasons Japanese firms have been so remarkably successful since the occupation.

The computer buyer, however, need not feel like a sucker when he or she practices the "Buy American" creed. There is simply no foreign-made personal computer now available that can match American products, and I don't know of any coming up in the next few months.

With the possible exception of the Epson QX-10 (although it sounds like a brand name that came over on the Mayflower, "Epson" is a Japanese brand), I can't think of a single Japanese computer I'd like to own.

Until this fall, I might have gazed longingly at the Radio Shack Model 100, which is a fine little machine even though it's built by Kyocera, a Japanese firm. But now American firms such as Hewlett-Packard, Texas Instruments and Digital have turned out their own lap computers to compete with the Model 100, and every one is superior to the Kyocera entry.

The British-made Apricot is an interesting little PC aimed at the educational market. But the fruit of choice in this field is still Apple, and should remain so for a long time to come.

Mighty Mitsubishi has entered the fray with an IBM clone desk-top computer sold here under the Sperry and Leading Edge brand names. Just when this model arrived, however, IBM cut it off at the knees with a price cut that makes the Mitsubishi machine noncompetitive. Leading Edge, a forward-looking company that should have known better than to rely on an offshore supplier, has been selling its computers at a loss just to stay in the market.

After years of dour predictions about a Japanese "invasion" of the personal computer market, foreign firms have only about 5 percent of the U.S. market -- most of it in the Model 100. The reason is that nobody has been able to match the quality, ingenuity and value of the American computer.

How sweet this is! Our country last year had a $35 billion trade deficit with Japan -- up from $10 billion just four years ago. In the past generation we have seen the transistor radio, the color TV and the pocket calculator -- all American innovations -- become virtual monopolies of Japanese companies and their economic "colonies" throughout Southeast Asia.

But now, with the most intriguing new product in decades, the personal computer, the United States is on top. And U.S. buyers, if they buy right, can keep it that way.