"Life is what happens while you're making other plans"  -- John Lennon

Some time ago, I became distracted from a compiler design project, and started playing with raster functions on an early PC.  I wrote the simple code to draw an Archimedean spiral by converting the equation...
r = theta
...into its Cartesian form:
x = theta * cos (theta * (pi / 180))
y = theta * sin (theta * (pi / 180))
Plotting pixels to represent the expected spiral, I was surprised to find a lissajou instead, arising from a misplaced term in the above conversion.  Extended with menus and animation, it became:

Psychedelic Trigonometry

This was one of my earliest development efforts, and I created the source from scratch using:
At that time, performance of 1.5 MIPS was state-of-the-art for a $3000 personal computer. 
After distributing Psychedelic Trigonometry at Cal Poly Pomona, I began writing System Information Graphics at my part-time job at MWD, and Astronomy Domine for my own pleasure, while finishing a bachelor's in Computer Science.

Forward to the Present

Although the architecture and graphics drivers have changed, thanks to Virtual DOS Machine, the binary that I last compiled in 1989 still runs on Windows 2000 and on: 
  • Windows NT and 2000
  • Windows 3.1+, 95, and 98
  • DOS 3.3+
A typical screenshot, mid-animation:

My friends John Kelly and Rosie Nguyen from Cal Poly Pomona witnessed the writing of this package, and persuaded me to post the ( DOS executable, after these many years.
Subpages (1): Source code