I spent a good part of my working life programming computers. I started in the late 60’s, almost fifty years ago. Back then, computers were the size of houses, and the programs were punched on cards. Data storage was on magnetic tape. Processors were slow and memory was small. But in the early 70’s when the microelectronics explosion happened, memories grew from kilobytes to megabytes to gigabytes to terabytes. Processor speed accelerated from kilohertz to megahertz to gigahertz. And of course the cost went down and down and down. Today, most kids carry one around in their pocket.