New Sega, Nintendo Add-Ons to Hit Market : Video games: Devices will boost speed of Genesis, put Game Boy on a television set.

There is no rest for the video game addict.

Nor, apparently, for the feuding manufacturers Sega and Nintendo, who each announced new products Monday designed to improve the performance of their technology.

Sega of America, whose Genesis machine sits atop the television sets of 13 million U.S. households, said that it will begin selling a $150 add-on cartridge this fall that will allow its 16-bit system to process data at twice the speed, making for better sound and more realistic, arcade-style graphics.

Nintendo of America introduced an adapter that lets players transfer the display of its ubiquitous Game Boy cartridges from the 2-by-2-inch, black-and-white Game Boy screen to full-color TV screens. The company expects to ship the $60 Super Game Boy adapter in June.

The competition for dominance in the next generation of video game machines has become increasingly intense as new-technology fervor draws more players into the $5.7-billion U.S. video game market.

For example, a news-release war between the two chief rivals in the field erupted last week over a report that Nintendo provided a congressional committee with a videotape of the most violent scenes from the Sega game Night Trap. It culminated in the following exchange between Sega President Tom Kalinske and Nintendo Chairman Howard Lincoln:

“I’m really amazed that Nintendo would . . . so irresponsibly drag retailers and the entire video game industry through the mud in their efforts to slow our momentum.”

Came the response: “Dear Tom, Roses are red, violets are blue, so you had a bad day, boo hoo hoo hoo. All my best, Howard.”

Analysts said the most recent moves by Sega and Nintendo represent attempts by both companies to extend the life of their older products as they build customer demand for a new generation of technology. For newcomer 3D0, which as of November had sold only 30,000 of its $700 compact disc-based game machine (the price has since been dropped to $500), the Sega add-on cartridge could be another obstacle in attracting customers at a higher price.

For consumers, the onslaught of product introductions and promises of introductions to come raises the question of whether to buy any of them at all.

“Confusion creates a wait cycle,” said Bruce Ryon, multimedia analyst for Dataquest, who forecasts a dip in the video game machine market next year. “The more announcements that come out from a technology standpoint, the more people hang back and say, ‘We’ll let somebody else invest in the mistakes.’ ”