Good designers borrow; great designers steal.

Almost nothing is really new in a product design -- no matter how much gets spent on research and no matter how much gets spent on advertizing. Out of shear commercial practicality 99% of everything in any "new" product must be recycled from some existing product or technology. And for this reason, out of an absolute necessity -- good designers borrow; great designers steal. (Of course when Picasso said something along those lines, he was talking more about art.)

A case in point...

Printed circuit board designers in the 1950s and 1960s connected components using curved traces that meandered with no fixed grid from point to point, believing that this was the most efficient way to lay out connections on a board (which in theory is correct).

But as component counts exploded in the 1970s and design times rose accordingly, somebody decided that a more structured planned-city type approach was needed to meet the demand for faster design turnaround. And so PC board designers abandoned the free form curved-trace motif in favor of a grid-based method where lines had to be straight and corners mitered in two neat steps of 45-degrees.

In the late 1970s a brief hiatus from the 45-degree mitering approach arose to accommodate the quirkiness of early computer aided design (CAD) systems -- these systems could not do the miters (PC board-designer-grumbling notwithstanding). And so for a few years designers were forced to use straight lines with 90-degree turns. Of course this did not last for long as designers under the gun kept clamoring for a return to 45-degree miters.

By the mid-1980s --finally-- mitered trace-routing had returned once this feature became standard on even the lowest-priced CAD systems. And then, for what seemed like an eternity, PC boards were all designed having 45-degree miters, and anything else looked more and more like Gramma's old '53 Studebaker.

But wouldn't you guess it -- some layout densities eventually reached the point where only a curved-trace method would work. And so after more than 40 years, the state of the art in high density board layout is beginning to once again embrace the curved-trace motif of the 1950s and 1960s now that CAD systems are able to support this "new" methodology.

As in all things creative, no good motif is ever lost forever.

Ken Ramsley