Software update turned my display and mouse upside-down, says user

Software, we don't need no stinking SW to flip your display!

When the VT100 (Digital Equipment Corporation) came out, it was designed for VERY easy service. Which also meant very easy physical hacking. Pop the top off and the magnetic yoke on the back of the tube could be rotated at will. Wise engineers will make sure there is no charge in the system by shorting some key points to earth - but a feature of the VT100 was that there were very few capacitors in there - not like older video terminals (or television tubes).

The yoke had a single screw clamp - easy to loosen with about a half twist of a screwdriver. Tilt the display whichever way you wanted.