- Octans was one of 14 new southern constellations introduced in the 1750s by the French astronomer Nicolas Louis de Lacaille. It represents a navigational instrument known as a reflecting octant, invented in 1730 by the Englishman John Hadley (1682–1744). Lacaille originally named it l’Octans de Reflexion on his chart published in 1756, but changed this simply to Octans on the second edition of 1763 on which he Latinized the names of the constellations.
- Two interesting XOR circuits inside the Intel 386 processor (righto.com)
Intel’s 386 processor (1985) was an important advance in the x86 architecture, not only moving to a 32-bit processor but also switching to a CMOS implementation. I’ve been reverse-engineering parts of the 386 chip and came across two interesting and completely different circuits that the 386 uses to implement an XOR gate: one uses standard-cell logic while the other uses pass-transistor logic. In this article, I take a look at those circuits.