In the Beginning was the Command Line (extract) by Neal Stephenson Retrieved from http://www.cryptonomicon.com/beginning.html The teletype was exactly the same sort of machine that had been used, for decades, to send and receive telegrams. It was basically a loud typewriter that could only produce UPPERCASE LETTERS. Mounted to one side of it was a smaller machine with a long reel of paper tape on it, and a clear plastic hopper underneath. In order to connect this device (which was not a computer at all) to the Iowa State University mainframe across town, you would pick up the phone, dial the computer's number, listen for strange noises, and then slam the handset down into the rubber cups. Anyway, it will have been obvious that my interaction with the computer was of an extremely formal nature, being sharply divided up into different phases, viz.: (1) sitting at home with paper and pencil, miles and miles from any computer, I would think very, very hard about what I wanted the computer to do, and translate my intentions into a computer language--a series of alphanumeric symbols on a page. (2) I would carry this across a sort of informational cordon sanitaire (three miles of snowdrifts) to school and type those letters into a machine--not a computer--which would convert the symbols into binary numbers and record them visibly on a tape. (3) Then, through the rubber-cup modem, I would cause those numbers to be sent to the university mainframe, which would (4) do arithmetic on them and send different numbers back to the teletype. (5) The teletype would convert these numbers back into letters and hammer them out on a page and (6) I, watching, would construe the letters as meaningful symbols. These embodied two fundamentally different approaches to computing. When you were using cards, you'd punch a whole stack of them and run them through the reader all at once, which was called batch processing. You could also do batch processing with a teletype, as I have already described, by using the paper tape reader, and we were certainly encouraged to use this approach when I was in high school. But--though efforts were made to keep us unaware of this--the teletype could do something that the card reader could not. On the teletype, once the modem link was established, you could just type in a line and hit the return key. The teletype would send that line to the computer, which might or might not respond with some lines of its own, which the teletype would hammer out--producing, over time, a transcript of your exchange with the machine. This way of doing it did not even have a name at the time, but when, much later, an alternative became available, it was retroactively dubbed the Command Line Interface.