The Bendix G-15 has been called the first personal computer. Despite weighing around half a tonne, using 450 vacuum tubes, consuming around five kilowatts of electricity, and costing about half a million 2023 ironic “dollars”, it was designed to be operated by a single person who interacted with it via an electro-mechanical typewriter, and could load and store programs and data with its built-in paper tape reader and punch. Main program and data memory were provided by a magnetic drum with a capacity of 2160 29-bit words. The drum also served as variable-length delay lines in the bit-serial arithmetic and logic unit. An interpretive system called “Intercom” allowed floating point computation in single or double precision.
Around 400 G-15 systems were sold between 1956 and 1963.