When my university first instituted "computer registration" back in the dark ages of computer punch cards, they had the library set up with tables manned by the various professors or their grad students, each with a pile of cards equal to the number of spaces available in the class. Students registering would go from table to table, collecting cards for the classes they wanted to take, and when all the cards for a certain class had been given out, the class was closed. When each student had collected all the cards for their classes, they would take their "registration packet" to a final table, where it would be handed in with their name and fees, and then the schedules would be drawn up accordingly by computer.
After observing this procedure the first time, a pair of enterprising computer students obtained a computer punch that made the same rectangular holes that were already in each card. They went to the library and set up a table at the end of the registration area, just before the table where the packets were handed in, and put up a sign that said, "All students must stop here." "Let me have your packet, please." (punch, punch, punch--at random) "Thank you very much." It took the university three weeks to straighten out the class schedule.