From: Jordan K. Hubbard (jkh@meepmeep.pcs.com) Subject: Re: mach 2.5 vs mach 3.0 Newsgroups: comp.os.mach View: Complete Thread (15 articles) | Original Format Date: 1992-05-26 07:21:26 PST In article <1992May19.213235.13879@ready.eng.ready.com> walden@ready.eng.ready.com (Eugene Walden) writes: >>> >>> +-----------+ +-----------+ +-----------+ +------------+ >>> | | | | | | | | >>> | BSD 4.3 | | DOS | | Bill's OS | | Ted's OS | >>> | | | | | | | | >>> +-----------+ +-----------+ +-----------+ +------------+ >>> >>>----------------------------------------------------------------------------- >>> >>> +----------------------+ >>> | | >>> | Mach 3.0 microkernel | >>> | | >>> +----------------------+ >>> >> >>Are you saying that DOS already runs under Mach 3.0? What *does* run >>under Mach??? (or "over" Mach, or whatever...) >> >>Rick Miller rick@ee.uwm.edu rick@discus.mil.wi.us uwm!discus!rick > > Anyway, just so I don't spread false rumors, no, DOS does not run on top > of the MACH 3.0 microkernel, but it probably could, if you took the time > to design the servers. > Actually, DOS DOES run on top of Mach right now (I know, I'm running it) but it looks more like this: +-----------+ | | | DOS | | | +-----------+ +-----------+ | | | BSD 4.3 | | | +-----------+ ----------------------------------------------------------------------------- +----------------------+ | | | Mach 3.0 microkernel | | | +----------------------+ This is because DOS currently relies on many of the features of UX (the BSD 4.3 server) for file I/O and whatnot. It doesn't HAVE to be this way (and from at least an asthetic standpoint, probably shouldn't be) but it saved the implementors time and energy and so it is. There are probably other and better reasons for it as well and one would do well to ask The Implementors. Jordan -- PCS Computer Systeme GmbH, Munich, Germany UUCP: ..!pyramid!pcsbst!jkh EUNET: ..!unido!pcsbst!jkh ARPA: jkh@meepmeep.pcs.com or jkh@violet.berkeley.edu