The Free On-line Dictionary of Computing (30 December 2018):

PC-ism

   /P-C-izm/ A piece of code or coding technique that takes
   advantage of the unprotected single-tasking environment in
   IBM PCs and the like, e.g. by busy-waiting on a hardware
   register, direct diddling of screen memory or using hard
   timing loops.  Compare ill-behaved, vaxism, Unixism.

   [Jargon File]