Comment by ben_w
13 hours ago
Mmm. Or improve the OSes themselves.
At this point, they could likely decompile MacOS classic and rework it to give it modern memory protection, virtual memory, preemptive multitasking, and networking.
I assume booting an OS with a mere few megabytes of RAM footprint would only take milliseconds?
> At this point, they could likely decompile MacOS classic and rework it to give it modern memory protection, virtual memory, preemptive multitasking, and networking.
You'd lose compatibility with the applications, though, so you'd have to decompile and rework those as well. And even if you did, you couldn't legally distribute any of it.
An alternative approach is high-level emulation. Running a separate instance per application gives you process isolation (via the host OS) for free.
> I assume booting an OS with a mere few megabytes of RAM footprint would only take milliseconds?
I haven't measured it as such, but yes.
> they could likely decompile MacOS classic and rework it to give it modern memory protection, virtual memory, preemptive multitasking, and networking.
It had most if not all of that.
It had networking from the start with AppleTalk, later Ethernet and internet with MacTCP.
MacOS 9 had a preemptively scheduled kernel.
The problem is having that and supporting the software ecosystem, which depended on cooperative scheduling without having memory protection.
MacOS 9 ‘solved’ that by running the classic OS in a single process. It had APIs for creating preemptively scheduled threads, but those threads were limited in what they could do.
You are getting your versions muddled up.
You are describing attributes of the NeXT-based OS X but calling it MacOS 9.
MacOS 9 was the final version of Classic. No preemption, weak virtual memory, weak cooperative multitasking, no virtual machines for anything.
MacOS 9 is the OS that ran inside the Blue Box on Mac OS X for backwards compatibility.
> You are describing attributes of the NeXT-based OS X but calling it MacOS 9.
You're mistaken.
> MacOS 9 [had] no preemption
Classic Mac OS has had vertical retrace (VBL) interrupts since System 1.0 (which are a form of preemption). But suppose we disregard that.
>> MacOS 9 had a preemptively scheduled kernel.
The GP is correct. Applications run cooperatively within the Blue task, but the Blue task itself runs preemptively with other MP tasks (which an application can create).
https://en.wikipedia.org/wiki/Mac_OS_nanokernel
https://en.wikipedia.org/wiki/Multiprocessing_Services
I am in the middle of doing this with apple's System 6 and adding a posix-compliant shell under the codename bluetail, and working my way up, i've got it booting with an os, busybox, openssh and stuff. Boots on a raspberry pi 3 A+ bare metal (And qemu, of course). And full usb MIDI support, because (I said so, and) there's actually an incredible catalog of early DAW software that will run on System 6. And pretty decent usb ethernet, sound, webcam etc etc. The future of hobby software is wild.
Please share anything you have, if possible. I'd love to know how you're doing it. If you don't want to do it publicly, my email is in my profile.
I've a wild whim to try this with Windows 95. What's an x11 or wayland? we're going EXPLORER.EXE!
Which model are you using? If Anthropic/OpenAI aren't you tripping any "cyber" blockage?
I am willing to check this out. I have 512Ke and Mac Plus hardware and am always looking for ways to maximize the hardware capabilities.
Woah I never even considered the possibly of rebooting old OS with new features. Very cool. Would love to experience that era of music tech
How did you implement that? Is it like a modified emulator with your enhancements added? How does the System 6 cooperatively multitasking stuff interoperate with the posix stuff?
Target system 7.5.3, it will run far more stuff.
I was going to say, why System 6 and not 7?
> Mmm. Or improve the OSes themselves.
Haiku specifically does not accept AI-generated code.
I expect if you use AI to explain how to write it and then write it yourself that would be okay.
You need to be able to explain your work without just pasting in what Special Needs Wintermute says.