This video shows a Macintosh 512k with newest revision "B" 64k ROMs retrofitted with a GCC HyperDrive, internal 10MB hard disk drive. This HyperDrive came out in 1985.
You can see how the shock absorbers work in my companion video here:
• GCC HyperDrive Shock Absorbers
And I've posted several photos of this system on my Flickr and Google Photos accounts here:
http://www.flickr.com/search/?q=hyper...
https://goo.gl/photos/orFejUKwgu1ynbbs7