1. Central Processing Unit. The main part of your computer, (not your monitor or sound card, for example).
2. Cayce Pollard Units. From William Gibson's science fiction novel Pattern Recognition
, non-brand-identifiable clothing: "things that could have been worn, to a general lack of comment, during any year between 1945 and 2000."
That hip consignment shop is all about CPU's--lots of basic black, and no logos.