Originally Posted by Speed Daemon
Sorry to say that's not right either. The notmePhone isn't based on UNIX® (that's how it's supposed to look, all caps) either. Check out Early's post.
Early did make one mistake. Mach is a microkernel, not a monolithic kernel.
Actually got tired of typing that on my phone.
I did Mach development for two years. As first released (escaped is a better word) from academia, it had a number of significant bugs (in the endlessly nested manifest constants) and was incapable of real time instrument support, areas that I fixed and modified.
Yes. Mach is a microkernel.
As Kernigan was fond of saying, any release from the typing mechanism is a benefit. It's one of the reasons that like so many who know its full background, I feel perfectly fine with the spelling cheats of unix, Unix and *nix.
And I assure you, OS X is based on the Mach MICROkernel. Before the public release (and in its first public incarnation), the Mach debug messages sang out loud and clear on any console bootup. I saw that quite often, with my own eyes. Pretty hard to mistake a Mach revision print statement.
By the way - http://www.informit.com/articles/article.aspx?p=1552774
As implemented for OS X, I believe that the hybrid is no longer a microkernel, as you say.
The rest I'm sure you know.