As some of you might already know, i work for a data recovery company here in Austria. This is why i see a lot of different harddisks and other types of storages. But this 5,25 inch disk is also very seldom to find. One of our customers sent it to us for a recovery. Cases like this are not so easy to recover because it is very difficult to find the old donor spare parts like a read/write head for the harddisk. This harddisk is from 1987 so it is as old as me. It is funny how much the components decreased in size. This harddisk had space for 40MB of Data, and a transfer speed of 625 KB/sec. So back in this time this was pretty good, but compared to todays technology a very old dinosaur.
https://support.necam.com/Legacy/HardDrives/D5146H.cfm
Old 5,25 inch harddisk. Picture: Florian Glechner.
Also the electronics on the back of the harddisk where pretty big. So it was probably much easier to repair and much more reliable than todays electronics of common harddisks.
PCB with Electronics on the back. Picture: Florian Glechner.