> The punch cards had 80 columns – 72 for the program and 8 for sequencing – so each line of code could be at most 72 characters wide.

In case anyone was wondering why the code only used 72 characters, it goes back to FORTRAN, developed on the IBM 701. The IBM 701 was a 36-bit machine. Its card reader loaded 80-column cards one row at a time (sideways to what you might expect), putting the hole pattern in two 36-bit words. Thus, it could only read 72 columns. (A pluggable wiring panel let you select which 72 columns you wanted, but normally it was set to columns 1-72). The 72-character limit has persisted in various places, even though the IBM 701 from 1952 is long gone.