I remember following the Therac-25 case at the time. If my memory serves me correctly, which is not always the case, the bug was caused by using the up arrow key to edit a parameter. The rather novel first bug fix was to remove the up arrow key.
Yeah, having done programming on Medical Imaging systems I would say that Therac is one of my top "bugs" of all time. In Medical Imaging, like some of the stuff I did, if the data isn't processed correctly it could cause the doctor to make a mis-diagnosis. Not good.
I think another one that some people will remember is the Memo field problem in dBase IV 1.0, if the user closed the memo field input via one method versus another it could 'clip' the remainder of the information in the field and loose it or corrupt the field in the database. This was one a couple of other nasty bugs in dBase that cost Ashton-Tate dearly (eventually aided in the companies death).
Another COTS bug that hurt a company bad was the Trash Can in MS-DOS 5.0, the base code was provided by Central Point Software (remember PC-Tools Deluxe) to Microsoft for DOS. Rumor was that at the last minute Microsoft tweaked the API code (for some oddball reason) in the DOS Trash Can and Central Point's own Undelete program couldn't get at files inside of the DOS trash can. Whoops! They had to do an unscheduled maintenance release, but Symantec/Norton had already jumped on it and had a fix in their Norton Utilities 5.0 release and Central Point couldn't catch up. Eventually Symantec bought out Central Point (for other reasons besides that one, like the Desktop for Windows suite which made Symantec a ton of money).
These other two, in the PC software world, are pretty significant to me because they contributed to the death of a company.
Yeah, yeah... those darn Navy guy's playing around with the guidance systems again while out on an exercise.
Reminds me of a Marine pilot buddy of mine telling me he had to go "Rabbit Hunting" on the back side of San Clemente Island with the Apache's machine guns before he headed home (can't come home with live ordinance) from a training exercise. Boy's with Toy's! [img]images/icons/wink.gif[/img]