Computer output microfilm (COM)
Writing a computer's output straight to microfilm instead of paper, for archives and high-volume reports.
COM solved a 1970s problem: a mainframe spitting out millions of lines a month drowned the archive in paper. A COM recorder took the data — from tape or directly — and exposed the pages onto 16 mm film or microfiche using a cathode-ray tube, and later a laser, at a fraction of the bulk and a lower cost per page than the line printer. Banks, insurers and government offices microfilmed statements and records this way for decades. The technology faded once cheap disk and searchable databases made a reel you had to spool through look clumsy, but film's durability means the archives are still with us.