How does the Classic environment works in OS X Tiger?

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mePy2
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How does the Classic environment works in OS X Tiger?

Post by mePy2 »

Hi, I would like to know how Classic works on Tiger. Mac OS 9 is cool since it is basically only a folder – understand what I mean xD.

Also, which is the difference between Classic and Rosetta?

Best,
mePy2
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mabam
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Re: How does the Classic environment works in OS X Tiger?

Post by mabam »

Classic lets you run software written for Classic MacOS if you're on a PowerPC Mac with OS X up to Tiger.

Rosetta lets you run software written for PowerPC OS X if you're on an Intel Mac with OS X up to Snow Leopard.

So Classic only works on Tiger if running on PowerPC hardware – or in a PowerPC emulator like QEMU.
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adespoton
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Re: How does the Classic environment works in OS X Tiger?

Post by adespoton »

Classic launches a virtual PowerPC machine on top of the existing OS, and patches it inputs and outputs into the host OS. This means it actually boots a full copy of OS 9 inside this virtual machine, and the windows from the applications are displayed inside Aqua.

Rosetta is both simpler and more complicated: it does Just-In-Time translation of 32-bit PowerPC instructions into their Intel x86 equivalent. It doesn't run a full operating system, so there have to be support libraries available that actually support all the APIs being called. To support this, 10.4 through 10.6 Intel came with Intel versions of all the core APIs used in 10.2 through 10.4 PPC. So when a piece of software called DisplayWindow, the endianness of the values would be flipped, but otherwise the call would be sent directly through, as the software didn't need to know that the host system handled the underlying code differently.
mePy2
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Re: How does the Classic environment works in OS X Tiger?

Post by mePy2 »

Hi,

Thank you guys. Yes, we talked a bit about Rosetta. And I would ask you what do you think about working on its port to newer macOS. I think we could continue the work done by _smartie77_ here: https://www.insanelymac.com/forum/topic ... a-on-lion/

They tested with SnowLeopard binaries, I would try using OS X Tiger x86 ones and or Leopard.

Anyway, a part from this.
I asked you about Classic because I had the impression, you have confirmed, that Classic is “just” an emulator on top os Mac OS X. Going to the point: What do you think about “porting” Classic to newer macOS? A QEMU machine that runs silently. The problem would be to make the programs to start with the “Acqua” interface like Classic did.

I think in the meanwhile a Rosetta workaround go ahead – IF people would like it to – maybe a Classic “clone” can be made!
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adespoton
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Re: How does the Classic environment works in OS X Tiger?

Post by adespoton »

mePy2 wrote: I asked you about Classic because I had the impression, you have confirmed, that Classic is “just” an emulator on top os Mac OS X. Going to the point: What do you think about “porting” Classic to newer macOS? A QEMU machine that runs silently. The problem would be to make the programs to start with the “Acqua” interface like Classic did.

I think in the meanwhile a Rosetta workaround go ahead – IF people would like it to – maybe a Classic “clone” can be made!
I've looked into this a bit and come to the conclusion that Classic is too deeply integrated into PPC OS X for this to easily work.

HOWEVER, the Classic environment from 1.2v3 isn't integrated into the OS at all, and behaves like a proper emulator, but passing the UI to Aqua. So I've been prodding at it in my (ha) spare time to see if we could build a wrapper around QEMU or SheepShaver that works in the same manner.

If someone with actual time available wanted to figure this out, I could provide advice where available... but most of my projects like this seem to take around a decade to complete these days, if they get completed at all.

This will, of course, all become further complicated in September when Apple drops support for 32-bit software. Some work is going on with WINE to provide 64-bit support, but it's not done yet; thankfully, we seem to have got Mini vMac, Basilisk II, SheepShaver and QEMU all compiling as fully 64-bit native now, so at least these will continue to work on the next macOS.
mePy2
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Re: How does the Classic environment works in OS X Tiger?

Post by mePy2 »

Hi,

Thank you adespoton.

Again, I know it requires effort and time. But if it is really feasible, and it is just a matter of time – of course not only time itself :( –, I think slowly, without stopping, we could achieve this – as any other thing, I think, in life.

Anyway... why Apple always has to complicate things?! What’s in the future that is so much better than what we had in the past and what we have now? 3d, incredible details in videogames?! Just for saying... I really don’t know. I’m fine with 2000 games anyway...
What’s the point of changing the OS? Wouldn’t security updates be enough?

Anyway, have I already talked to you about this project? https://www.powerpc-notebook.org/en/
Give it a look! If you have question ask me, I’ll try to reply, I’m a bit into it too. And if you want to contribute... oh you already are in the business :P
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