Wired have a great article on the sights and smells of historic computing, the strange beauty indeed of the "olden days" of computing : mainframes, minicomputers, line printers and other historic computing artifacts. Many of the computers and peripherals at places like the Computer History Museum in California (somewhere i must visit one day!) still work after being restored adding an extra dimension to the experience. The sound and heat of a punched card reader...
It is a very different tech world to now, a bigger world too. Computers filled huge rooms with printers being the size of small cars, plus tape units the size of wardrobes. That is part of the fascination i feel, its just so different to the computing we use now.
Unfortunately by the time i entered work we were past the age of old iron, though i did use a Prime minicomputer at university which was great fun. The biggest computer i've ever had physical access to is a HP PC server which was the size of a small fridge. Just not the same as a room full of IBM 360. One place i must try and get to this year is the UK National Museum of Computing which includes a fair amount of old iron in it's collection.