Apparently this a common practice, then. In the aviation case the problem seems to be that critical avionics components like fly-by-wire control systems are rea

Apparently this a common practice, then. In the aviation case the problem seems to be that critical avionics components like fly-by-wire control systems are real-time systems in which correct behavior depends not only on hardware interfaces but also temporal properties like response time. Upgrading to new hardware would potentially break the software in difficult-to-predict ways.