In 1971 IBM delivered a working 52-bit magnetic bubble memory chip to NASA as part of a contract investigating replacements for space-borne tape recorders. 
The photos on this page show some of the hardware details.  Click
here
to view the paper,
or
here
to watch a brief movie clip of the chip in action. 
(Turn the sound on). 

^M
^M
^M
After 7 seconds, 3 bubbles are written into the storage loop. 
(Movie is rotated 180 degrees relative to the diagram.)