If you're going punch-card, give this wikipedia article a read.
http://en.wikipedia.org/wiki/Punched_tape
Many people don't know the history of computers. Everyone knows that they started with cards, but few people seem to know that it quickly evolved to punched paper tape. In a steam setting, you could even take it further. Perhaps to power on his robots, he needs to read several reels of tape into the machine to load the complex program.
Basically, anywhere you would see magnetic tape today, you could have reels of punch tape in an alt-history.
Fun fact: the US military <b>still</b >uses this stuff today. When I was in the military just a few years ago, I had to use a portable tape reader to load encryption keys into a video teleconfrence system. We where a remote office, and the overhead of using electronic key management was a hassle and too expensive. The tape could be treated like any standard secret documents and simply stored in a safe and burned in a steel barrel when we where done with it. Electronic management requires a full room to be setup and secured with expensive locks and other unique requirements, not to mention a special stand-alone computer to be installed that was used only for manageing encryption keys.
This message was last edited by the GM at 13:49, Thu 05 Sept 2013.