The problem begins even in describing the prototype "dual-deck" videocassette recorder of Go-Video Inc.

The tiny Arizona company calls it a revolutionary "next generation" machine for the home video market that, for about $650, will allow people to copy home movies for grandparents, record films off the air while they watch rental tapes or edit training films for the office. Go-Video can't wait to start saturating the market.The Motion Picture Association of America, however, sees things a bit differently. Charged with protecting the interests of the movie industry, the association sees Go-Video's product as a high-tech piracy tool that would facilitate theft of copyrighted movies on a grand scale. According to The Wall Street Journal, association president Jack Valenti once likened marketing the machines to "selling a skeleton key that can open the front door to any home in America."

For the present, it is unclear whether the machines will ever reach store shelves. The reason is a complex mixture of trade battles between Japan and the United States and a years-old feud played out in the courts, press and Congress between powerful companies that sell recording equipment and powerful companies that sell movies and music.

The fight revives issues that have led to similar battles over sales in this country of ordinary VCRs and the newly developed digital audio tape recorders, which give much higher recording quality than conventional audio tape machines.

Go-Video's dual-deck machine looks like an ordinary VCR, except that it holds two tapes at once and can transfer recorded material between them. Similar results can be obtained by linking two ordinary VCRs together.

Other companies have developed similar machines. In 1984, Sharp Corp., one of Japan's largest makers of consumer electronics gear, began shipping dual-deck machines to Saudi Arabia and Kuwait, which have thriving video markets. None was sold in the United States, but the news provoked an angry outcry from Valenti's group and others who pointed to the potential for piracy.

The company later discontinued the machines, and press reports in Tokyo in April 1985 said the Electronic Industries Association of Japan had crafted a "voluntary restraint agreement" whereby member companies would not make the machines.

No Japanese company has made the machines since that time, however. In 1986, the Samsung group of South Korea, which has licensed VCR technology from the Japanese, announced plans to enter the market but later it too backed off.

Across the Pacific, in Scottsdale, Ariz., startup company Go-Video was not willing to drop out. In 1984, it had filed for a patent for a dual-deck machine and was trying to line up production facilities. It says that in 1985 it was negotiating with the Japanese electronics company NEC Corp. to make the machines for it, when suddenly NEC broke off the talks.

Go-Video said its teams subsequently scoured East Asia for a supplier of crucial VCR parts that are not made anywhere in the United States. But every time a seller found out they were from Go-Video, talks ended.

In response, Go-Video has launched a political campaign, depicting itself as an innovative American underdog that wants to wrest back some of the consumer electronics industry from Japanese giants that are determined to maintain monopoly power. "This technology has been withheld from the American public because the Japanese have decided that they don't want any competition in VCRs," says R. Terren Dunlap, Go-Video's chief executive officer.

At the company's urging, several members of Congress have written the Japanese government to demand sales. The Office of the U.S. Trade Representative also has raised the issue with Japanese officials.

Last year, the company took its fight to court, suing the Electronic Industries Association of Japan and virtually every big name in the Japanese electronics industry and the U.S. film industry. In a $250 million suit at U.S. District Court in Arizona, it alleges that these parties have engaged in a conspiracy against Go-Video in violation of antitrust laws.

All of the defendants have denied the allegations. In papers filed with the court, the Electronic Industries Association of Japan has specifically said it never had an agreement to block production of the machines.

Japanese equipment makers and American movie makers are not used to being on the same side in a courtroom. They had been adversaries in a 1970s lawsuit over sale of VCRs that eventually ended with a Supreme Court decision that home taping of movies did not violate copyright laws.

Go-Video says piracy fears are unjustified because it has built its machines to block it. If film companies place an anticopying code on the tape of copyrighted films, the machine will detect it and shut off. Very few tapes on the market have such codes, which at times can degrade picture quality.

Last month Go-Video was tentatively awarded a U.S. patent for a two-deck VCR. The news, which Go-Video described as a breakthrough, sent its stock prices soaring. But its problem in getting components remain unsolved. Trial is expected to begin next year, assuming that there is no out-of-court settlement.

In the meantime, officials at the Motion Picture Association, once more than happy to attack the machines publicly, are declining comment on the case. In its suit, Go-Video is trying to use press accounts of association officials' statements as evidence of a conspiracy.