This IBM 1620 was where most of us learned to program a computer. Under the tutelage of Professor Nimitz, we wrote code in Fortran on punch cards, which the computer compiled into an enormous stack of cards, which held the commands in machine language. To execute the program, you fed the big stack into the computer, and if there was a single error, you had to throw out the entire stack and start over. An entire corner of the computer lab was fenced off as a disposal area for the waste cards.
The computer had only two forms of output, punch cards and teletype. There were no CRT monitors.