About computer power a saw a programme which outlined how the Apollo moon landings were made on a computing shoestring. All those consoles had the computing power of a mobile phone. They were connected to a mainframe that had the power of a laptop. Amazing.

For more historical perspective check out the SAGE building, as I knew, it when 'taking Dad to work'.

At least one of these buildings still exist, at Minot AFB, ND. The computers are long gone, and even the original HVAC designed to cool the 2 x 3MW computers has finally been replaced by a modern HVAC system suitable for the human occupants in their many offices. No windows, and impressively thick walls and floors.

Hmmm, never thought to search for still standing buildings. The few times I've searched with various text strings the returns have included archival info, mostly from museum sources.