IBM 3800

Announced in 1975 and installed from 1976, it married a laser, xerography and tractor-fed continuous forms, running at some 13,000 lines a minute, about 215 pages. Resolution was 240 dots per inch, enough to draw both text and rules.

The rules were the whole point. Until then every company bought cartons of preprinted stationery — invoice templates, payslips, statements — and the line printer filled in the blanks. The 3800 printed the form and its contents in a single pass, which turned a warehouse of preprinted stock from an asset into an expense. At something like half a million dollars it went into mainframe rooms rather than onto desks, and the family stayed in production well into the 1990s.