Re: Worth the RISC
"You'd've thought so, but I've recently contacted the developers of two Mac applications I'm rather fond of (both of them first came out on 68k Macs). They're currently only available in a 32 bit version.
According to the developers, the only way they can convert them to 64 bit is to completely re-write them in Apple's Swift language which they are having to learn. And that's going from Intel to Intel...
On the other hand, I'd guess that if you've got a fully 64 bit application written using Swift and XCode, then Apple will arrange things so that converting an Intel application to ARM will be low-effort, assuming that Macs are switched to ARM CPUs."
Going from 32 bit to 64 bit can produce all kinds of problems, especially if the code was written at a time where nobody that 64 bit might ever exist. As you said, built for 68k Macs initially. That would have been before 1990.
What these developers probably have is _ancient_ code ported to MacOS X using the Carbon framework, which was never ported to 64 bits. That would have happened around 2002 or so when MacOS X was introduced, and stopped being supported about six years ago. There is no requirement to switch to Swift, Objective-C would do just fine. But 32 bit won't run on MacOS 10.15 anyway (that's the next version after the just released one).
Intel 64-bit vs Arm 64-bit using modern frameworks is no problem. The capabilities of both processors are the same, so any code not using Intel assembler code will compile and run identically.