You are right, it is pretty crazy how many CPU architectures Apple has been through. But look at it this way. Where are the competitors who didn’t do this? Amiga, Sun Microsystems, SGI etc. All dead.
I loved the Motorola, but lets be real it had no future. It hit the wall. It had the same pros and cons as other CISC processors such as intel x86, except it did not have the volume. Intel could negate the advantage of its RISC competitors by going for volume. Motorola did not have that option with the 68 000 architecture.
One could argue Apple should just have switched to intel from Motorola, but that would have been a profoundly risky move. All their software would have run way slower in emulation. PCs would have looked way better than Macs.
When Apple switched to PowerPC, it was such a superior CPU that most of their software ran equally fast or faster in emulation. They destroyed intel on benchmarks back in those days. It looked for a moment like Apple could finally have a way of presenting themselves as being a superior hardware platform.
Of course by the time Apple switched to intel, they where in the same situation as with Motorola 68 000 years earlier. At a dead end. Relying on other chip makers to provide them with an advantage but failing to do so.
This has really been part of learning curve for Apple. One of the first lessons they learned was that they had to control their development environment and the compiler technology. This his them hard in previous transitions.
Now most Mac development happens through XCode and using Clang and LLVM. Technologies Apple has strong control over.
This ARM transition is the last piece of the puzzle. The one thing that has burned Apple again and again: Being completely dependent on a third party hardware company which cannot deliver.
Their reliance on IBM and Motorola doomed them with PowerPC. With ARM Apple is finally experiencing the kind of control they have always craved. Since they design the chips themselves they are not at the mercy of others.
And they finally have a weapon against PCs which they never wielded before: Volume and economies of scale. Perhaps what is more important than technology alone.
Through companies such as Foxconn and TSMC they are getting the volume advantage they need in manufacturing. And iPhone and iPads are giving them a large volume to distribute their ARM development costs over.
Back in the Motorola and PowerPC days they did not have any second legs like this to stand on. PowerPC volume could only come from building Macs.
I got to spend some more time reading your 1802 article. I feel I need to read more on the initial stuff leading to this thinking. I think assembly programming and CPUs are kind of cool even if I have ignored the topic for a long time. I am playing around with TIS-100 and some other assembly games at the moment.
Anyways I have learned my lesson from the PowerPC days. It is not the most awesome and geeky cool technology that wins in the end. When analyzing and judging whether we have a winner or not, I think we need to look at the economics, volume and scale as well.
ARM is probably not the best RISC processor ever. But it has an appealing business model and economics of scale which means the architecture just makes sense.
We knew Intel could work their way around their architectural deficiencies by having higher volume. With ARM controlling the whole tablet and smart phone market they have a uniquely strategically strong position.
And honestly if another better architecture should rise up, well… Apple has everything they need to make a 5th transition. Unlike the PC guys they control their whole platform. They control the compiler, IDE, bytecode and hardware. Their OS is fairly well abstracted away from the hardware.
When Apple makes a transition it is easy to be onboard. Developers will rewrite their software because they know this is where everybody is going. There is no alternative.
If Dell OTOH switch hardware platform, who is going to care? Software writers are just going to shrug. HP and other will continue to make hardware their software already runs on.
What if Microsoft makes a transition? Well everybody will shrug yet again. Microsoft cannot force Dell, HP, ASUS and everybody else to switch hardware platforms. Not to mention Microsoft has made their name on backwards compatibility and never really rocking the boat.
Everybody on the Apple platforms know Apple is in charge for good and bad. They know you got to play it the Apple way. That the gain and advantage of being on that platform is that sometimes there are some radical changes. But we know Apple has been through this many times. And we know they can pull it off, so we put our trust in them and we go along with it.
The same cannot be said about Microsoft. Pretty much every alternative hardware they have tried besides x86 has been failures: Alpha RISC CPUs. Where are those today? Windows ARM tablet? A failure in so many ways. They couldn’t even get their own flagship software running on it.
So the time Apple has to make the correct hardware transition for all eternity is over. Making hardware transitions is now one of their key advantages. It is a thing they know how to do. It is one of their not-so-secret weapons they can pull whenever it is needed.