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Newsgroups: comp.os.386bsd.questions Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!elroy.jpl.nasa.gov!swrinde!cs.utexas.edu!uunet!mcsun!sun4nl!relay.philips.nl!cnplss5!rooij From: rooij@mozart.cft.philips.nl (Guido van Rooij) Subject: Re: DOS/Windows under 386bsd (is there such?) Message-ID: <1993May25.082233.22564@cnplss5.cnps.philips.nl> Sender: news@cnplss5.cnps.philips.nl (USENET News System) Nntp-Posting-Host: mozart Organization: Philips Communications & Processing Services, Eindhoven References: <1tgme7$n0q@urmel.informatik.rwth-aachen.de> <1993May20.234750.5815@fcom.cc.utah.edu> <1tmn92INN6el@hrd769.brooks.af.mil> <1993May24.182422.7719@gmd.de> Date: Tue, 25 May 1993 08:22:33 GMT Lines: 36 veit@mururoa.gmd.de (Holger Veit) writes: >Should be at cs.vu.nl, I believe. I doubt that it is quite helpful, because Right. >it does emulate the processor. So, to answer the question above: the emulator >can circumvent the page write bug, and this way emulate a 386 without problems. >But I am quite sure that DOSEM uses the native virtual-86 mode the 386 processor >already has, with its own 640K environment and traps that handle the >more critical problems like redirecting interrupts and interpreting >privileged I/O instructions. DOS (at least until DOS3.3, without the nitty things like >himem.sys and emm386.exe) is quite happy with a 8086 (even a vm86()-emulated one). >The native ROM-BIOS, however, should be replaced by emulator-traps, because it >deals with things 386bsd or Linux as the host does not like to see, like >messing around with the I/O devices. Furthermore, today's modern 386BIOS versions >partly run in 386 mode, which is trapped by the virtual-86 environment. >Mapping the DOS I/O and filesystem environment to the Unix environment is >basically the task performed by the DOS emulator, supported by the kernel >that prepares a closed and protected virtual-86 subsystem. There just has been released a new dos emulator for Linux. It even has VGA graphics in it... I think, when trying to make a dos emulator for 386bsd, you can better wait till 0.2 comes out because it should have a per process IO bitmap. It makes things more easy. Btw: whta happened to all ppl working on a dos emulator? I saw somepostings long time ago about someone porting the mach stuff. What happened to him/her? >Holger >-- > Dr. Holger Veit | INTERNET: Holger.Veit@gmd.de >| | / GMD-SET German National Research | Phone: (+49) 2241 14 2448 >|__| / Center for Computer Science | Fax: (+49) 2241 14 2342 >| | / P.O. Box 13 16 | Three lines Signature space >| |/ Schloss Birlinghoven | available for rent. Nearly > DW-5205 St. Augustin, Germany | unused, good conditions -Guido