An absolutely wonderful write-up. My first contact with punch cards was in 2005. As a tradition, my alma mater uses two punch cards and magnetic tape to make

An absolutely wonderful write-up. My first contact with punch cards was in 2005. As a tradition, my alma mater uses two punch cards and magnetic tape to make the name tags for the new computer science students. Supplies are of course limited, so this is a dying tradition. I remember reading about how they worked and even, late on a Friday night, learning a bit of Fortran that could have been punched onto my name tag. From the older professors I learned about the diagonal stripe trick and that the biggest fear they had on a cold winter day was to slip when carrying a box of cards down the long nasty stone stairs just outside the maths department, when taking their code to the computing centre. Something that I did not see mentioned in the submission that I learned from them was that at least some computers in the 60;s would make a different sound depending on which instruction that was being processed. Now, remember that this, just like in the article, was before the days of displays. So, a way to detect infinite loops was to listen to the machine. An infinite loop would of course be detectable by the same sound pattern repeating itself over and over. Auditory debugging indeed.