Chris Oxlade 
History of Computers [PDF ebook] 

Do you know that computers were only invented within the past 100 years? And that the smartphone was only recently invented, in the mid-1990s? Yet today, computers and other devices are everywhere in our lives — in classrooms, homes and public places. From the first calculating machines made of cogs and wheels during the 1640s to virtual reality headsets such as Oculus Rift, this book charts the incredible history of computers.