If you are interested in historical big computers, you probably think of IBM, with maybe a little thought of Sperry Rand or, if you go smaller, HP, DEC, and companies like Data General. But you may ...

C. 2500 BCE: Sumerian abacus -- c. 700 BC: Scytale -- c. 150: Antikythera mechanism -- c. 60: Programmable robot -- c. 850: "On Deciphering Cryptographic Messages" -- c. 1470: Cipher disk -- 1613: ...