Promising unlimited color possibilities, new bi-color and RGB LEDs are available in a variety of through-hole and surface-mount packages. Suitable for full-color moving message signs, general status indication, consumer products, backlighting, large-scale graphics displays, and instrumentation, they cost 25 cents each in production quantities.
BivarOpto Div., Bivar Inc., 4 Thomas, Irvine, CA 92618. (949) 951-8808.

Engineering, Freedom, and the 28th Amendment
Karl Stephens

Picking Glass Out of My Eyes
David Mantey, Editor, PD&D

Asteroid Mines: The Good, the Bad, and the Ugly
Karl Stephan, Consulting Engineer, Texas State University, San Marcos