@nikitonsky this misses out the human stage in the loop, where you have to retype (or even re-punch) any card that has a visible error in it.
And once you have your corrected card deck (perhaps 2000 cards) you have to feed it into another machine that read the stack of cards and send it to the mainframe that queues it for processing and 24 hours later prints out pages and pages of fan sheet paper with all the logged cascading program errors, or occasionally your actual answer.