Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!elroy.jpl.nasa.gov!decwrl!netcomsv!resnicks From: resnicks@netcom.COM (Steve Resnick) Newsgroups: comp.os.msdos.programmer Subject: Re: Physical addresses in protected mode? Message-ID: <1991Jun25.174941.8081@netcom.COM> Date: 25 Jun 91 17:49:41 GMT References: <4948@gumby.Altos.COM> <1991Jun25.023154.16683@maytag.waterloo.edu> Organization: Netcom - Online Communication Services UNIX System {408 241-9760 guest} Lines: 29 In article <1991Jun25.023154.16683@maytag.waterloo.edu> dmurdoch@watstat.waterloo.edu (Duncan Murdoch) writes: >In article <4948@gumby.Altos.COM> rcollins@altos.COM (Robert Collins) writes: >> >>If you are in V86 mode, then give it up because you are executing at IOPL=3 >>which makes it impossible to get the physical address. > >If running under VCPI, there's a call to find the physical address corresponding >to any V86 address. This is done by calling INT 67h with AX=0DE06h, CX=the >linear V86 address shifted right 12 bits. It returns with EDX holding the >physical address of the page. I imagine DPMI has a similar service, but >I don't have the spec. DPMI Does support a virtual-to-physical address translation. I don't have the spec here, but I will dig it up if someone wants the info.... Let me know via mail .... Steve -- ------------------------------------------------------------------------------- resnicks@netcom.com, steve@camphq, IFNA: 1:143/105.0, co moderator for comp.binaries.os2 Real life: Steve Resnick. Chief Software Architect, Process Scientific, Inc Flames, grammar and spelling errors >/dev/null The Asylum OS/2 BBS - (408)263-8017 12/2400,8,1 - Running Maximus CBCS 1.2 -------------------------------------------------------------------------------