Copland - looking for information, have d11e4 running

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Copland - looking for information, have d11e4 running

Post by plat »

Wasn't sure if this is the right place to post this, but figured the Mac guys might know. I'm wondering how much information is out there about the internal workings of Copland? I know it has pre-emptive multitasking, protected memory, and supposedly a micro-kernel architecture.

The micro-kernel part is especially interesting, because that design has never been used in a real, functional operating system that is/was actually used. It's kind of the holy grail in OS design(but difficult to implement), so to speak.

Basically interested in how it works under the hood, so to speak. It is very interesting seeing various status information printed to the screen during startup, starting SystemProcess, initializing devices, finding system libraries, etc. Very un-mac-like.

I have d11e4 running on a PowerMac 7100/80. If anyone has any questions or is interested in how it runs, I'd be happy to do some testing.

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Re: Copland - looking for information, have d11e4 running

Post by sparcdr »

Copland was slated to have multithreading and proper SMP (Preemption), though as stated by Wikipedia's article on classic MacOS releases among others (Announcements archived from releases) not all of the R&D that went into Copland made it into any of their production releases and developers stated it was more like a bag of technologies than an OS anyway. What it said is that the Finder was rolled into OS 8 and that there was still no process separation when they attempted to retrofit threading and mp into the core.

MK-LINUX, WindRiver's RTOS, CMU Mach (DEC OSF-1, Ultrix, Tru64, NeXTStep then OpenStep) and finally OS X are the known micro-kernel implementations (Hybrid or native) that were/are in production at the time or still are. The closest model to Copland in using lightweight and self-supporting/healing services in the architecture was/is BeOS of the day (1998) also for PowerPC, even though it was actually monolithic as a whole. The extended status information you have is due to it being a developer preview rather than being un-mac-like.

There is MorphOS (AmigaOS semi-proprietary clone) for eMac, PowerBook and PowerMac (PPC again) which uses a MK design. The archived back and forth between Andrew S. Tanenbaum and Linus over USENET may paint a better picture on why at the time such a complex design was impractical given hardware limitations.

As far as the API for Copland, some of it may be tucked in the 1997 Developer Library which some of us have an offline copy of (Mainly due to Carbon API depreciation) though as it never made it to public release it could have been on discs under NDA at the time too.

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