Re: Humidity control
Long enough ago and far enough away that I can remove anonymity from the guilty...
It would have been in about 1984 and the place was the head office of a company called Locamion in Lyons, France. Back in those days smoking in France was more or less compulsory, and the atmosphere in the office was pretty much opaque. This much was expected, but when I went into their machine room I discovered an unusual modification had been made to the MDS disk drives. Ash trays had been added so that they could convince the operators to remove their cigs from their mouths for the time taken to switch disk packs. That stopped them getting fag ash on the platters and thus reduced the frequency of head crashes.
Otherwise the room was climate controlled and had temperature and humidity tracking, just like all the others. In fact the "Computer Room" used to be the one place you could escape summer heat and pollen.
1) Huge washing machine sized contraptions with on exchangeable disk drive at the top (6 platter 18" diameter beasts with 60MB capacity) and a 640MB non-exchangeable drive at the bottom.