[TUHS] First Unix-like OSes not derived from AT&T code?

[Ron Natalie]

All I remember was that the Metaware compilers came with prayer book.  

> On May 3, 2022, at 09:43, Miod Vallat <miod at online.fr> wrote:
> 
> 
>> 
>>> At the end of the AOS work circa 1996, most of the kernel was 4.4,
>>> except for the network stack which was 4.3-Reno, and the VM system which
>>> was still 4.3 (hence no mmap).
>> 
>> 
>> This happened outside of IBM, didn't it? What prevented the rest of the VM
>> code being ported?
> 
> Most - if not all - the AOS work was done by Roger Florkowski and Mark
> Dapoz, and Roger was definitely working for IBM at that time.
> 
> I think time was limiting factor, but also Roger was not really wanting
> to port the Mach VM to AOS due to the RT MMU limitations - in
> particular, there is no way for multiple virtual addresses to point to
> the same page, so you need to keep evicting/switching mappings when you
> want a page to be available to the kernel and the currently running
> userland process. That was fixed in the POWER MMU.
> 
>> I vaguely remember Metaware being somewhat religiously extreme, but again
>> the details are fuzzy now. Was there some kind of ecclesiastical reference
>> in the man page?
> 
> I'm afraid that doesn't ring any bell.
> 
> Miod