DEC PDP-11/20 Minicomputer, 1970

Digital Equipment Corporation's PDP 11 computers were popular, widely used machines in the era before personal computers. These 16-bit minicomputers ("mini" as opposed to the room-sized mainframe computers of the 1950s and '60s) were relatively inexpensive and were used for business (payroll, accounting), scientific, educational, and timesharing purposes. Many Americans were introduced to computing through PDP 11s installed at schools and offices beginning in 1970.