In 1981, when I was born, it was the moment people now retroactively call the PC revolution. Before that, most people did not have computers. They had terminals where they typed into a mainframe computer somewhere in the cloud: a big financial institution, a big research institution, or a big state. The problem is that you only get a time share. You do not control what software to install, how to change it, or how to tune it. Everything you type, the sysop sees.