IBM, in what the computer giant termed its largest worldwide product announcement ever, unveiled on Tuesday its long-awaited mid-range computer, a $30,000 to $1 million system intended for small to intermediate size businesses, the fastest growing segment of the economy.

In a press conference at Little America Hotel, held simultaneously with other such meetings nationwide, IBM announced its new family of IBM Application System/400, the results of what IBM described as the "most massive hardware and software undertaking in the company's history."According to IBM vice president Edward E. Lucente, the six AS/400 models, and the single Operating System/400 that controls them, are designed to grow in capacity as their users require. They are also an option, said Lucente, for larger companies to use in departments or remote locations.

Along with the new hardware, IBM announced more than 1,000 software packages ready for use with the equipment - the largest such joint announcement in computer history.

Lucente said the software will allow the AS/400 to be used immediately by companies in, among others, retailing, manufacturing, finance, distribution, health, legal, transportation, insurance and education.

"The announcement of these systems begins a new era of easy-to-use processing power for commercial customers," said Lucente. "With a rapidly expanding list of application solutions to boost their productivity, the AS/400 will be the growth engine for many business, from small to large."

From the smallest to the largest model, Lucente said, the AS/400 delivers a 24-fold growth range in main memory, a 48-fold growth span in storage capacity and a 10-fold performance range in the number of commercial transactions it can process per hour - up to 45,000.

The system is also designed to accommodate future technological advances, such as optical storage, expert systems, business image processing, voice-data integration and communications.