Maybe, but it isn't easy. Often the code is written around the performance of the hardware in question. Thus you still have to rewrite all the software before any new hardware can be used. Or write an emulator that is cycle perfect to hard real time standards. Neither is cheap or easy.
I know of companies (I can't talk about which) that spent a few billion dollars trying to replace old hardware, only to abandon the track taken and have to start over. All the while the stores of the obsolete and no longer made CPU are getting smaller and smaller. All this for a controller that marketing doesn't see any reason to add more features so they can't even justify some off the cost as new features.
I know of companies (I can't talk about which) that spent a few billion dollars trying to replace old hardware, only to abandon the track taken and have to start over. All the while the stores of the obsolete and no longer made CPU are getting smaller and smaller. All this for a controller that marketing doesn't see any reason to add more features so they can't even justify some off the cost as new features.