They were also used in the Star-100 SBUs. For the
life of me, I never
figured out why drums and not disks, but 'twas so. A lot of military
aircraft computers used them also.
Drums can tolerate a bad landing much better than a disk.
The givewaway there would be the 400 Hz
spindle motor.
Not just aircraft, but shipboard as well.
William Donzelli
aw288 at
osfn.org