IBM Upgrades Minicomputer Line : Technology: The most powerful of the new mid-range AS/400 series will include a 16-million-bit memory chip.

NEW YORK —  International Business Machines Corp. refreshed its entire line of minicomputers Tuesday, announcing 13 new models in its second major upgrade of the line in less than a year.

The most powerful of the new E series of AS/400 mid-range computers is the first in the industry to include a 16-million-bit memory chip, used in a card that boosts storage capacity by 30%.

IBM said that machine, the E90, is 70% more powerful than the top-of-the-line AS/400 D series computer.

The AS/400 line, introduced in 1988, has been one of Big Blue’s most successful areas, contributing about $4.5 billion in hardware revenue to its application business systems unit in 1991.

The 7% increase in AS/400 revenue came as IBM was posting its first-ever overall revenue decline. Total AS/400 revenue, including all of the related sales the line generates, accounted for about $14 billion, or 22%, of IBM’s total.

IBM said the number of AS/400s installed last year jumped about 50% to more than 150,000 worldwide. AS/400s are machines that come midway between mainframes and personal computers.

Much of the AS/400’s popularity is based on the extensive software that runs on the machines.

“The AS/400 is not a number cruncher,” said Clifford Friedman, an analyst at Bear Stearns. “It’s a box that solves a customer’s application problems, and you won’t find a better one.”

“We plan to introduce 16-million-bit technology in new products this year and beyond,” said Paul Low, IBM vice president of technology products. IBM added that the new top-of-the-line AS400, the model E90, also uses the computer giant’s new 1-billion-byte, 3 1/2-inch disk storage device.

It said the E90 uses three processors linked together and the same architecture, called N-Way, as the two-processor D80 it replaces. The company also announced new AS/400 software.

IBM also announced two new printers, the first offerings from Pennant System, a wholly owned subsidiary formed late last year when IBM announced a corporate restructuring.

The new products will be available March 6, IBM said.

On the New York Stock Exchange, IBM closed down 12.5 cents at $89.625 a share.