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.