From: "Alexei A. Frounze" Newsgroups: comp.os.msdos.djgpp Subject: Re: far pointers Date: Sun, 11 Jun 2000 15:32:36 +0400 Organization: None Lines: 45 Message-ID: <394378D4.90FA4822@the_messasge_body.com> References: NNTP-Posting-Host: ppp96-237.dialup.mtu-net.ru Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: gavrilo.mtu.ru 960724059 76013 212.188.96.237 (11 Jun 2000 11:47:39 GMT) X-Complaints-To: usenet-abuse AT mtu DOT ru NNTP-Posting-Date: 11 Jun 2000 11:47:39 GMT X-Mailer: Mozilla 4.72 [en] (Win95; I) X-Accept-Language: en,ru To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Reply-To: djgpp AT delorie DOT com Eli Zaretskii wrote: > > The point is that it is IMHO misleading to say that V86 *allows* DOS and > PM programs to coexist. V86 has nothing to do with PM programs that use > DOS. It makes the mode switch faster in some cases, but that about all > it does for PM programs. Okay, if you like to change CPU mode completely and waste time, you're welcome. If you wanna miss advantages of PMode you're welcome too. But infact, V86 is the better way to have both PMode stuff and real-mode programs. You may dislike coexistance here, but more or less it is present here. > [V86] means programs like DOS can coexist with protected-mode programs. > > My comment was that this is misleading, because V86 does nothing to > *allow* coexistence between DOS and PM programs. They can coexist with > or without V86, But not always. :) Switching back to real mode implies that 1st MB must be free for that. I doubt it's nice to move all the PM stuff around the RAM just in order to run some BIOS or DOS function. > and special measures are required in both cases to make > that coexistence possible. > > > It would be impossible to have (let's say) a disk I/O in DJGPP under > > DOS without V86. > > Please explain why do you say so. DJGPP can work on bare-bones DOS > machine without any V86 monitor. All you need is CWSDPMI, and CWSDPMI is > *not* a V86 monitor, on a vanilla DOS system it really switches the CPU to > plain real mode (not to V86) when it calls DOS. Well, looking through CWSDPMI sources I realize it really has nothing about V86 under true DOS. Interesting fact... bye. Alexei A. Frounze ----------------------------------------- E-mail: alexfru [AT] chat [DOT] ru Homepage: http://alexfru.chat.ru Mirror: http://members.xoom.com/alexfru