He did it in FORTAN? FORTRAN was old when I was in High School. I graduated in the 90’s.
Had to remain conversant in it, as some old PLC and DCS programs have it, but I haven’t seen any “new” programs in fortan since... well since the one I wrote in Basics of Programming for Chemical Engineers.
That was 1995 .
FORTRAN is still used quite extensively for serious number-crunching. For instance,
https://en.m.wikipedia.org/wiki/Basic_Linear_Algebra_Subprograms