The company at which I was working purchased a second hand VAX 11&#x2F;750 system around 1984 and a Digital engineer came in to help us re-commission it.<p>Everything went well until the RM05 (256MB) disk pack performed a random-seek confidence test; it was then that we discovered that its feet had not been screwed down to the floor and the whole unit started to breakdance around the computer room like a deranged washing machine. Two of us leapt at the unit and held it down until the test completed.