Apple IIe Motherboard X-Ray

Isn't this why they make CPUs and other chips "RAD HARD" for aerospace/military use? I seem to remember a reference relating to the 1802 where one of its selling points was the sapphire substrate. Or am I suffering from bit rot? Rich Rich Cini Collector of classic computers Lead engineer, Altair32 Emulator Web site: http://highgate.comm.sfu.ca/~rcini/classiccmp/ Web site: http://www.altair32.com/ /***************************************************/ -----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] On Behalf Of William Maddox Sent: Thursday, December 28, 2006 9:27 PM To: General Discussion: On-Topic and Off-Topic Posts Subject: RE: Apple IIe Motherboard X-Ray X-rays can damage ICs. While searching for information on possible risks to electronics from x-ray security screening, I encountered a second-hand reference to a study to determine the safest X-ray wavelengths and exposure for nondestructive testing of high-reliability ICs. X-rays can inject faults into the silicon lattice, which degrade the quality of the transistors. I think the exposure that can be tolerated is affected by geometry (e.g., transistor size), so it might not be as much of an issue for older electronics as it is for newer stuff. Anybody know more? --Bill