https://lowendmac.com/2014/the-g5-and-mac-os- … han-youd-think/

All classic Mac OS would be entirely 32-bit, G5 was the first 64-bit mac CPU and it came *waaaay* after apple was done with OS9.

I'm a bit surprised they didn't try harder considering some of the Powermac G5s could be equipped with up to 16GB RAM but I guess they would have known not to bother since the x86 switch was coming.

Expack3 wrote on 2023-06-26, 14:14:

Anyways, I recently came across a claim I hadn't heard before: namely, games and applications which run on PPC Mac OS (aka Mac OS Classic) are 32-bit only. As I'm more familiar with how Windows has historically handled EXEs of differing bits, I'd be very interested to hear how Mac OS handles it, if at all.

Sounds about right. A more interesting topic in this area would be how they handled the fact that binaries could contain 68000 code, PowerPC code, or both. There was also early Mac hardware where the top 8 address bits were ignored and then abused as flags (including by the firmware) and this had to be worked around aka "32-bit addressing."

Error 0x7CF wrote on 2023-06-26, 20:45:

I'm a bit surprised they didn't try harder considering some of the Powermac G5s could be equipped with up to 16GB RAM but I guess they would have known not to bother since the x86 switch was coming.

Maybe, I think for a while there, in general, there was a belief in sticking with 32-bit userspace: http://web.archive.org/web/20190108141947/htt … -and-elsewhere/

The thing is that the modern web is so bloated (not just the sites but the shift to users keeping 5000 tabs open), and desktop applications bloated as a result of the move to Electron, that programmers can't write anything bigger than "hello world" in a 32-bit address space any longer 😁