Source : Free On-Line Dictionary of Computing

blit
     
        /blit/ 1. To copy a large array of bits from one part of a
        computer's memory to another part, particularly when the
        memory is being used to determine what is shown on a display
        screen.  "The storage allocator picks through the table and
        copies the good parts up into high memory, and then blits it
        all back down again."  See {bitblt}, {BLT}, {dd}, {cat},
        {blast}, {snarf}.  More generally, to perform some operation
        (such as toggling) on a large array of bits while moving them.
     
        2. Sometimes all-capitalised as "BLIT": an early experimental
        {bit-mapped} {terminal} designed by Rob Pike at {Bell Labs},
        later commercialised as the {AT&T 5620}.  (The folk etymology
        from "Bell Labs Intelligent Terminal" is incorrect.  Its
        creators liked to claim that "Blit" stood for the Bacon,
        Lettuce, and Interactive Tomato).
     
        [{Jargon File}]
     
        (1994-11-16)