Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!rutgers!att!cbnews!cbema!las From: cbema!las@cbnews.ATT.COM (cbema!las) Newsgroups: comp.sys.ibm.pc Subject: Re: UNIX runs DOS applications? Message-ID: <11688@cbnews.ATT.COM> Date: 22 Nov 89 20:55:31 GMT References: <1989Nov17.202018.10930@ico.isc.com> Reply-To: cbema!las@cbnews.ATT.COM (Larry A. Shurr,20650,cb,9a110,6148605851) Organization: AT&T Bell Laboratories, Columbus, OH (actually an AGS consultant) Lines: 33 In article <1989Nov17.202018.10930@ico.isc.com> rcd@ico.isc.com (Dick Dunn) writes: }jca@pnet01.cts.com (John C. Archambeau) writes: }} ...But I would not run any sort of implementation of VP/ix }} (i.e. DOS Windows) on a 286 box because the 286 is brain damaged with respect }} to flipping in and out of protect mode, that and there's no virtual 8086 mode }} like the 386 has... }This is quite off. VP/ix is a facility which works in a 386 UNIX system, }period. The question of running VP/ix on a 286 simply cannot arise, }because you cannot run a 386 UNIX system on a 286. But beyond that, VP/ix }makes explicit use of "virtual 8086 mode" which (as correctly noted) does }not exist on a 286. Uhh... sorry, but that turns out not to be the case. There have been versions of VP/ix ("spelled" it right, this time :-)) and it's like competitor, DOSMerge, for the 80286 for some time. They work as described, by flipping the 286 between its real and protected modes with much futzing around in software to integrate into the host Unix environment. When the 386 became available, both products were reimplemented to use the virtual 86 mode (there's still lots of futzing around in software, but at least the chip provides the necessary support). It is true, of course, that the new 386 versions cannot be used on a 286. Also, I don't think that VP/ix has anything to do with Windows; though Windows 286 does some bizarre messing around of its own involving (I've been told) the "secret" LOADALL instruction. regards, Larry -- Signed: Larry A. Shurr (cbema!las@att.ATT.COM or att!cbema!las) Clever signature, Wonderful wit, Outdo the others, Be a big hit! - Burma Shave (With apologies to the real thing. The above represents my views only.) (Please note my mailing address. Mail sent directly to cbnews doesn't make it.)