40 years ago we entered the megabit memory era with IBM’s DRAM breakthrough — a major leap beyond the 64 kilobit chips common at the time

40 years ago we entered the megabit memory era with IBM’s DRAM breakthrough — a major leap beyond the 64 kilobit chips common at the time

By Mark Tyson
Publication Date: 2026-04-19 12:04:00

40 years ago today IBM was in the news for becoming the first computer company to make use of 1-megabit memory chips. Thus, the megabit memory era began with an American company and its Vermont fab leading the way, pushing back stubbornly against the seemingly unstoppable Japanese takeover of the memory market.

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(Image credit: SK Hynix)

IBM’s 3090 (Sierra series) mainframe computers were the first to adopt this new high-density memory. However, the New York Times reported the occasion as “a rare, if fleeting, moment of glory,” as it thought the Japanese semiconductor industry would inexorably rise beyond its already impressive 75% market share.