Funnily enough we had one of those (or something like it) in the college I went to, also in an open bench top computer. The HD had no cover, and you had to give

Funnily enough we had one of those (or something like it) in the college I went to, also in an open bench top computer. The HD had no cover, and you had to give the disk a spin to get it moving after power-up. Oddly it never suffered ill-erects from environmental contamination of the head / platter. I guess the densities were low enough not to matter so much.