Those perforations which many people ended up using for an additional speaker were actually intended as a feeble attempt at encouraging airflow through the vertically mounted cards. Those, if you remember, were full-length back in those days, and because of that fact would have benefitted had there actually been enough pressure difference between outside and inside to cause the air to flow substantially. IBM had people who were really worried about noise, hence wouldn't put a meaningful fan in the box. That little thing in the PSU (which dies more often than any other single component in any PC) won't move enough air to cool things much. It will move enough air to load everything in the box with dust, though. Dick -----Original Message----- From: allisonp(a)world.std.com <allisonp(a)world.std.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Friday, July 02, 1999 2:36 PM Subject: Re: PC form factor