Business Notes ELECTRONICS

"I just can't bring myself to buy a compact-disc player until I have something in writing that says that's the last thing they're going to invent," says comedian Rita Rudner. Sorry, Rita. Now there's a major new format to agonize over: digital audio tape. Sony's model DTC-75ES, the first mass-market DAT recorder available in the U.S., began arriving in stores last week.

While the machines have been sold in Europe and Japan for more than two years, the U.S. debut has been delayed by controversy. Reason: the recorders can produce flawless copies of CDs, which has raised fears in the music industry of a surge in illegal "pirate" tapes. Sony and other electronics manufacturers have agreed to equip their DAT recorders with special circuitry to prevent the machines from making multiple copies of the same tape, but many record companies and artists want Congress to write this agreement into law.

Such concerns could prove irrelevant, since consumer resistance to DAT may well render it DOA. The machines are dear: $950 for Sony's model, vs. $150 for a cheap CD player. But DAT's biggest flaw is that it may quickly become obsolete. Japanese companies are already working on a recordable CD, and the Dutch electronics firm Philips has developed a new format called digital compact cassette. DCC machines, which unlike DAT recorders can play traditional as well as digital tapes, could be available as early as next year.