Mary Adelman, whose Manhattan typewriter-repair shop tended to machines with shift-lock keys that would do neither and carriages that would not return — and to the people who pounded away on them — died on Wednesday in Washington. She was 89.

The cause was complications of dementia, her daughter Anne Adelman Taswell said.

For decades Mrs. Adelman’s shop, Osner Business Machines, at 393 Amsterdam Avenue, just south of 79th Street, was an emergency room for typists with bent keys, problematic platens and ruined ribbons.

It was a dusty leftover from a time before word processors and, even more newfangled, computers — a place that at its busiest would be jammed with typewriters that could be repaired, cannibalized for parts or sold. Most had been flipped on their ends to let Mrs. Adelman squeeze in more.

She maintained that a typewriter was “a personal item that has meaning, not just a piece of metal.” But the shop was not just about the typewriters. It became an Upper West Side fixture in the lives of people desperate to keep the words flowing. Some hunted and pecked. Some poked with two fingers. Some approached their QWERTY keyboards with the poise and careful hand positions of a pianist.