Source : Free On-Line Dictionary of Computing

PC-ism
     
        /P-C-izm/ A piece of code or coding technique that takes
        advantage of the unprotected single-tasking environment in
        {IBM PC}s and the like, e.g. by {busy-wait}ing on a {hardware
        register}, direct diddling of {screen memory} or using hard
        timing loops.  Compare {ill-behaved}, {vaxism}, {Unixism}.
     
        [{Jargon File}]