Hi, On Wed, Jan 9, 2013 at 12:43 PM, dmccunney <dennis.mccun...@gmail.com> wrote: >>> >>> EMS used a 64KB page frame located in the block between 640K and 1MB, >>> and paged memory above 1MB into it for use. >> >> I vaguely thought EMS 4.0 didn't need a page frame? (Where's Eric to explain >> all this when you need him? Heh,) > > I don't recall. But the underlying issue is how you access stuff > above 1MB RAM on a CPU with a 1MB address space. For the CPU to see > it, it must be in the 0K - 1MB range, and that mandates copying it > from RAM above 1MB into that range. This means you need a defined > area in the 640-1MB range were it will be copied, and will mean you'll > have to page stuff into it in chunks that will fit in that area. > Sounds like a page frame to me.
Dunno. Perhaps the pages could be smaller (VCPI? 4 kb?) instead of 16 kb. I haven't really done a lot of EMS programming, to say the least. (This is why I would rather someone like Eric Auer or Japheth explain it, but it's not really crucial.) > It didn't come standard because most folks would not understand it or > use it. It would have been a support nightmare for little perceivable > benefit. I would almost agree, except DOS has had VDISK for years and years. And I don't remember it being such an alleged support nightmare. But probably some shmo said, "Windows is fast enough" (ugh). > And NTVDM has worked fine here, but I'm strictly doing character mode > stuff. I don't care about DOS games using graphics, and didn't play > them when I used DOS. I don't claim to know the details. All I know is that some apps had very annoying bugs that weren't present (not to mention some missing functionality). Not everything was able to be recompiled or updated like DJGPP (and thus 2.03p2 or newer is recommended), so it's running into a brick wall expecting certain things to work. I don't think they're totally incompetent, they just don't care. It's just sad when they basically drop support for anything legacy. I'm sorry, "controlling the standard" may look good on paper for running a company, but it's just too destructive for my tastes. We really really "really" shouldn't have to recompile simple "ANSI C" apps 10 bazillion times because of OS changes. (I guess the unofficial workaround [since everyone refuses to get along] is to use portable scripts, e.g. Lua. Though even that has minor issues due to lack of standards. And even standards are often ignored.) >>> The Firefox port is >>> third-party - Mozilla officially supports Windows, OS/X and Linux - >>> but the underlying code was designed to be portable. For that matter, >>> I believe there are still people doing VMS ports. >> >> I don't think "portable" is the right word here. All modern software, for >> whatever trendy (but insane) reason refuses to play nice outside of their >> own niche. Usually that means (at best) the big three, even if sometimes >> they (falsely) hide behind standards (e.g. POSIX). They can't even reliably >> stick to anything, it's always a constant upgrade, very frustrating. > > Netscape made strenuous efforts to make the core Mozilla code > portable. It's written in C++, so that meant "Just because you can do > it in MS Visual C++, don't assume it works elsewhere That was in 1998 or such. Back then they forbade developers from using templates! Nowadays they can't even barely keep up with what's going on. They dropped Win9x in 2006. They don't officially support anything outside of the big three, and even Firefox for Windows still isn't "officially" available as 64-bit (probably due to LLP64). Of course, being one of the most complicated pieces of crap^H^H^H^H ... software in the world probably doesn't help. (A web browser is 100x more difficult than it used to be ten years ago.) I'm not really knocking them, just annoyed that portability seems to be achieved so easily for popular platforms, but for others, people pretend they can't even test or write a simple makefile, sheesh. It's just a mess, and I can't help but feel it's arbitrary, not technical, limitations. ------------------------------------------------------------------------------ Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. ON SALE this month only -- learn more at: http://p.sf.net/sfu/learnmore_122712 _______________________________________________ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
