Margen
The first commercial hard drive weighed more than a ton, had to be moved by forklift or cargo plane, and stored less than a single photo on your phone: about five megabytes.
It was the heart of the IBM 305 RAMAC, unveiled in 1956. It kept data on fifty metal disks, sixty centimetres across, that spun without stopping while a mechanical arm moved between them to read and write. It was a revolution: for the first time, a company could reach any piece of data instantly, without rewinding tapes.
It wasn't sold, it was rented, for about 3,200 dollars a month in the money of the day. Today a one-terabyte memory card, smaller than a fingernail, is worth two hundred thousand RAMACs. Lined up in a row, those cabinets would weigh as much as two aircraft carriers.
Source: IBM