The ST-251 was a 42 MB hard disk drive, made by Seagate in the early 1980s. The recording has the drive spinning up and self-testing (as it would do when turned on) and then spinning down (being turned off).
Nowadays, most computers use (silent) SSDs and even modern hard disks don't make these sounds.
This is part of the Obsolete Sounds project, the world’s biggest collection of disappearing sounds and sounds that have become extinct – remixed and reimagined to create a brand new form of listening. Explore the whole project at https://citiesandmemory.com/obsolete-sounds
