In the early 1980s, Sandia National Laboratories developed the SA3000, a radiation-hardened version of Intel's 8085 processor. The lab needed custom ICs for extreme environments like nuclear warheads and space probes where commercial components couldn't survive. Starting with 2-inch wafers in 1978, they upgraded to 4-inch wafers by 1982, producing over 50,000 chips for the Galileo mission to Jupiter.

Converting the original 6,500-transistor HMOS design to CMOS proved challenging. The instruction decoder required significant redesign since large PLAs work differently in NMOS versus CMOS. The resulting SA3000 contained 18,000 transistors and operated at 4.5-11V for radiation tolerance, while maintaining 5V compatibility for testing. Manufacturing used n-on-n+ epitaxial substrates with extensive guard rings and hardened oxides to control latchup effects.

The SA3000 achieved remarkable radiation resistance—surviving 1×10⁶ rads with only 25% performance loss, far exceeding the 1×10⁵ rad design goal. It powered the W88 nuclear warhead's main computer for altitude and fuzing calculations, flew on Ball Aerospace's star tracker, and supported the CRRES satellite mission in 1990. Despite CRRES's early battery failure, the hardened electronics functioned properly.

Harris commercialized the design in 1990 as the HS1-80C85RH (space grade) and HS9-80C85RH (military grade), though with reduced voltage ratings and slower speeds than Sandia's original. This represents a fascinating intersection of semiconductor engineering and national security applications.