Musical Data General
In the 1980s I ran a DG Nova with a 5+5 removable Phoenix drive attached to a very large, expensive, scientific instrument. I got funding to replace the drive with a Winchester. The new drive was mounted in a 19" rack enclosure contained in one side of a of a knee-hole desk unit that housed the CPU etc on the other side. The drive could be slid out on rails for servicing and we all admired the platter and drive head beneath its transparent top cover. The read-write head had an electromagnet "voice coil (So called because it made a pleasant melodious sound when it operated?). The head had an aerofoil cross-section and "flew" just above the surface of the rotating disk.
I found out the reason why a common failure of a hard disk was called a "crash": I was listening to the musical hum as I ran an experiment when there was a faint bang followed by a loud scraping sound. When I turned the DG off and opened up the rack, the inside of the transparent plastic cover was coated with oxide and I could see a large spiral radial gouge mark on the platter. I called in the service engineer who told me that the repair/replacement cost was our problem as it was an "normal" event. I think the cost was about the same as my new car.