Seems to me that you just have to be careful when bringing out a new version. You can't change the memory model from chip to chip but that goes for x86 to. Not sure what other behaviors are not really changeable.
Can you give me an example of this? SPARC of the late 90s ran 32bit SPARC.
Can you give me an example of this? SPARC of the late 90s ran 32bit SPARC.