The Evolution of Removable Storage
Brave users of history's earliest computers programmed those massive electronic beasts through jumper wires plugged into arrays of sockets. With so few computers in existence (none of them compatible with any others), digital pioneers had little need for portable software: The programs stayed put. Soon, however, companies like IBM began selling multiple identical computers, and users sought a way to program the devices more efficiently, to move programs from computer to computer, and to reload programs later with a minimum of hassle.
Thus begins the history of removable computer storage, which in many ways is the story of software distribution: The first job of removable storage was to share software without requiring any reprogramming from scratch. Over the next few pages, we'll revisit dozens of ways that engineers have solved the problem over the past 60 years.