Source : Free On-Line Dictionary of Computing

Great Runes
     
        Uppercase-only text or display messages.  Some archaic
        {operating system}s still emit these.
     
        See also {runes}, {smash case}, {fold case}.
     
        Decades ago, back in the days when it was the sole supplier of
        long-distance hardcopy transmittal devices, the Teletype
        Corporation was faced with a major design choice.  To shorten
        code lengths and cut complexity in the printing mechanism, it
        had been decided that teletypes would use a monocase font,
        either ALL UPPER or all lower.  The Question Of The Day was
        therefore, which one to choose.  A study was conducted on
        readability under various conditions of bad ribbon, worn print
        hammers, etc.  Lowercase won; it is less dense and has more
        distinctive letterforms, and is thus much easier to read both
        under ideal conditions and when the letters are mangled or
        partly obscured.  The results were filtered up through
        {management}.  The chairman of Teletype killed the proposal
        because it failed one incredibly important criterion:
     
          "It would be impossible to spell the name of the Deity
          correctly."
     
        In this way (or so, at least, hacker folklore has it)
        superstition triumphed over utility.  Teletypes were the major
        input devices on most early computers, and terminal
        manufacturers looking for corners to cut naturally followed
        suit until well into the 1970s.  Thus, that one bad call stuck
        us with Great Runes for thirty years.
     
        (1994-12-02)