Download raw (2.7 KB)

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.