The IBM 2501 Card Reader. The installation of these units for public use in late 1971 was a significant step along the path of bringing users and "the computer" closer together. Now, instead of handing in your deck of cards at the Operator window and coming back the next day to get the results, you could submit your job yourself.
There was usually a line for the card readers. Jobs might be anywhere from 30-40 cards to several boxes of 2000 cards each. Jams were frequent, and cards were often "eaten" by the reader, in which case you went back to the keypunch to make replacement cards, losing your place in line.