Timeline of Computer History

The Colossus at work at Bletchley Park

First Colossus operational at Bletchley Park

Designed by British engineer Tommy Flowers, the Colossus is designed to break the complex Lorenz ciphers used by the Nazis during World War II. A total of ten Colossi were delivered, each using as many as 2,500 vacuum tubes. A series of pulleys transported continuous rolls of punched paper tape containing possible solutions to a particular code. Colossus reduced the time to break Lorenz messages from weeks to hours. Most historians believe that the use of Colossus machines significantly shortened the war by providing evidence of enemy intentions and beliefs. The machine’s existence was not made public until the 1970s.


Harvard Mark 1 is completed

Harvard Mark 1 is completed

Conceived by Harvard physics professor Howard Aiken, and designed and built by IBM, the Harvard Mark 1 is a room-sized, relay-based calculator. The machine had a fifty-foot long camshaft running the length of machine that synchronized the machine’s thousands of component parts and used 3,500 relays. The Mark 1 produced mathematical tables but was soon superseded by electronic stored-program computers.


Hadoop logo

Hadoop is developed

Cuthbert Hurd (standing) and Tom Watson, Sr., at IBM 701 console

IBM ships its Model 701 “Defense Calculator”

Brown Box reproduction by Ralph Baer

Ralph Baer designs the Brown Box

Storage Tek tape library

Storage Tek 4400 ACS tape library

IC memory on top of core

IBM System 370 Model 145 mainframe computer