Way back in the 70s a PET was the platform for my first paying programming job. Given an equation for a transformer hysteresis curve with a couple of parameters, I was tasked to plot hysteresis curves graphically.

For maximum info-density and maximum aesthetics, I got deeply into the character set for block graphics, so that every position in the plot had the character that best fit the curves and made them as smooth and cool and informative as possible.

It was a great introduction to the craft.