pizza box

pizza box n.  [Sun] The largish thin box housing the electronics
   in (especially Sun) desktop workstations, so named because of its
   size and shape and the dimpled pattern that looks like air holes.

   Two meg single-platter removable disk packs used to be called
   pizzas, and the huge drive they were stuck into was referred to as
   a pizza oven.  It's an index of progress that in the old days just
   the disk was pizza-sized, while now the entire computer is.