Although the tape deck is near the end of its life, an MP3 player just hitting the market aims to give the venerable device a new purpose.

New Vernon, N.J.-based Digisette has begun selling the $250 Duo-MP3, a portable MP3 player that not only looks like a cassette, but also can be popped into a traditional tape deck to play its stored music. That's because in addition to serving as a digital music player, the Duo-MP3 has a converter that allows digital music to mimic the analog signals of a cassette.

"All you do is press play and it will start playing," said Jeff de Gracia, the start-up's vice president of marketing. Press fast-forward for more than a second and the Duo will sense the increased speed of the cassette player and skip to the next song. Press rewind and it goes back a song.

When it's not sitting in a tape deck, the unit works like other portable MP3 players.

The initial version of the Duo-MP3 comes with 32MB of flash memory, enough for only about 30 minutes of CD-quality sound. However, the unit can be expanded with add-on flash memory using the Multimedia Card format.

Technology such as that used in the Duo-MP3 was shown off by several Asian manufacturers at the Consumer Electronics Show in January in Las Vegas. The 20-employee Digisette gets its units from one of the companies, Korea-based HWI. Digisette said it also has secured licenses to key intellectual property that should give it a corner on the U.S. market.

The unit, advertised in a weekend newspaper circular from Amazon.com, is also being sold through Outpost.com and traditional stores including Staples, Babbages, Everything Wireless and FAO Schwartz.

The Duo-MP3, which hit stores earlier this month, gets downloaded music from a PC using a parallel port connection and has a rechargeable battery that gives about six hours of play time.

Brian Ma, an analyst with market researcher IDC, said the idea behind the Duo is intriguing.

"It's interesting just in that we're talking about adapting to the existing infrastructure," Ma said, noting that there is a lot of experimenting going on with different designs for MP3 players.

De Gracia declined to say how many of the players he expects will sell this year but said it will certainly be at least in the tens of thousands.

"I'd love to have PlayStation 2 problems, but I don't think we'll get those numbers this year," he said. Digisette is also working on upgrades to the Duo, as well as other products.

So is an 8-track player version in the works?

"That's a little too retro," de Gracia said.