About the Biorhythm Charting Service
The origins of the program that creates these biorhythm charts dates
back to the early days of the minicomputer, circa 1973, when Brian
Johnson ("Uncle BJ") created a Fortran program that "plotted" a
biorhythm chart on fan-fold paper using a line printer attached to a
Data General Nova
(maybe it was even DOS rev. 5).
In 1976, I converted Uncle BJ's program to the
C programming language
UNIX version 6
as an exercise in learning C
and UNIX-style file I/O, this time creating output on a
Then in 1998, more than two decades later, I again used it as a
learning exercise, this time creating a self-referencing
Portable Network Graphics
(PNG) images for the world wide web.
Over the years I've lost track of Uncle BJ, and his whereabouts
today are unknown. As for me, you can read more about what I do
on my web site.
February 6, 1998