By that point, computers were better at time-sharing--that is, mainframes were still mainframes, but they were better at communicating with a large number of terminals at once. Consequently, it was no longer necessary to use batch processing. Card readers were shoved out into hallways and boiler rooms, and batch processing became a nerds-only kind of thing, and consequently took on a certain eldritch flavor among those of us who even knew it existed. We were all off the Batch, and on the Command Line, interface now--my very first shift in operating system paradigms, if only I'd known it.

A huge stack of accordion-fold paper sat on the floor underneath each one of these glorified teletypes, and miles of paper shuddered through their platens. Almost all of this paper was thrown away or recycled without ever having been touched by ink--an ecological atrocity so glaring that those machines soon replaced by video terminals--so-called "glass teletypes"--which were quieter and didn't waste paper. Again, though, from the computer's point of view these were indistinguishable from World War II-era teletype machines. In effect we still used Victorian technology to communicate with computers until about 1984, when the Macintosh was introduced with its Graphical User Interface. Even after that, the Command Line continued to exist as an underlying stratum--a sort of brainstem reflex--of many modern computer systems all through the heyday of Graphical User Interfaces, or GUIs as I will call them from now on.

GUIs

Now the first job that any coder needs to do when writing a new piece of software is to figure out how to take the information that is being worked with (in a graphics program, an image; in a spreadsheet, a grid of numbers) and turn it into a linear string of bytes.