Univac 9400 disc drives
Disc drives have a much smaller access time compared to
tape drives. On the other side, the controlling of the drive
and the 10 heads is very complex, so they needed a whole
cabinet with electronics (in the photo only particulary mapped).
The storage capacity of the original 8414 series is 7.5MB per disc pack. Our drives (1970s, 8425 series) can already store 50MB. For that time, this was an incredible size.
We have currently connected three drives, as you can see in the picture.
The disc heads are amazingly big. The moving coil (on the left hand)
plunges into an heavy pot magnet (not visible in the picture) and
thus moves the complete slide on it's position.
Therefore it works just as an ordinary loudspeaker, but the moving masses are much higher. The predecessor still moved the sled pneumatically.
There is a bottle of wine in the right hand of the picture for comparison.