Hi, On Mon, Mar 30, 2015 at 10:09 PM, dmccunney <dennis.mccun...@gmail.com> wrote: > On Mon, Mar 30, 2015 at 8:37 PM, Rugxulo <rugx...@gmail.com> wrote: >> >> If DOS is "out of the loop", then why are you still able to run DOS >> files (.COM, .EXE, .BAT)?? Does Windows emulate it? Or is it really >> just calling back to DOS itself? What is responding to the int 21h >> kernel calls? > > <sigh> This is OS development 101. Do you think a new OS intended as > a followup to an existing product throws out the baby with the > bathwater and does everything differently, so existing apps won't run?
YES!!! Are you really this naive? I'm honestly not even cynical enough for this. Lots of companies throw everything away, on purpose, and expect everyone else to just deal with it. If they can get away with it, they absolutely will do it. > It includes it. Part of the problem for Windows 9X was maintaining > backwards compatibility. It needed to be able to run old 16 bit DOS > apps as well as apps written for Windows. Batch files were > interpreted by COMMAND.COM, and COMMAND.COM was available. In Win9x, COMMAND.COM (a DOS MZ executable) was the sole shell. So there was no other choice. In fact, most of the 16-bit Windows stuff (since Win 3.0) was DPMI-based. The 'D' stands for "DOS", so it can't live without it. > COM and EXE files were programs run under the OS, and Windows supported the > system calls those programs used. There would be no need to call the > underlying DOS, because the required stuff was part of Win98. Wrong. If there was a bug in the underlying DOS, then that exact same bug was also found under Windows. These were not two separate implementations. > I repeat, DOS was a real mode loader, whose function was to load > Windows. Once it had, Windows took over. Not at all. At least not in Win9x. A lot of programs (EDIT, DEBUG, EDLIN) were still DOS programs. >> For something like Windows XP, then definitely DOS isn't there, it's >> emulated in NTVDM. But to pretend that Win98 runs all by itself >> without DOS is a bit of a stretch. > > No, it isn't. Win98 needed DOS to load it. That's it. And that > requirement is a consequence of X86 segmented architecture with real > mode and protected mode. The machine started in real mode, and needed > a real mode loader to load the protected mode OS. Not at all. DOS is far more than just a boot loader. If that's all it did, it wouldn't need separate hardware drivers or FAT / ISO9660 file system code at all. (Often there were Windows-only drivers, but DOS was still available.) > NT finally removed that requirement and could be booted without DOS, > but the issues of maintaining backwards compatibility made getting > there a one step at a time process. At one time, MS was fiercely loyal about compatibility. (Allegedly, that's why IBM fired them from OS/2.) But that was the old days. Those days are long gone. They really don't care as much anymore. For example, they want Win32 to die in lieu of "Metro" (or "Modern UI" or whatever they're calling it now). >> Hasn't this already been discussed to death before? MS was later sued >> (and lost) for illegally bundling their DOS with their Windows. I > > I don't recall that, and rather doubt there was anything illegal about > it. MS owned MSDOS and Windows, and could use them and bundle them as > they desired. Apparently not. They lost a lot of money. They claimed that it was technically impossible to use any other DOS, but it was later shown that was totally wrong. They just didn't want anyone else to compete with them. >> think Caldera (or Lineo or whatever they were eventually called) even >> legitimately proved that they could boot Win95 atop DR-DOS. Win95 and >> MS-DOS weren't bundled for technical reasons, only marketing reasons. >> It was much closer (technically) to Windows 3.1 than most people >> realize. > > You could indeed boot Windows atop DR-DOS, but why bother? No. It was long known (and bragged about, "faster!") that DR-DOS could boot Windows 3.1. That's not the issue. Microsoft intentionally bundled their MS-DOS so that nobody else (e.g. PC-DOS or DR-DOS) could run Win95. They purposely said it was impossible, but it was very easily proven otherwise. This is similar to (but worse) than the old AARD warnings. > You would only be likely to do so if you already ran DR-DOS and wanted to run > Windows too. And remember, DR-DOS began because DR had customers > wanted a ROMmable version of DOS for embedded applications. MSDOS at > the time was not architected to provide the required separation > between code and data, and could not be embedded in ROM. Offering > DR-DOS as a consumer product was a later development. I could be wrong, but I thought DR-DOS was meant to capitalize on the MS-DOS craze. Since PC-DOS cloned CP/M, the makers of CP/M-86 decided to clone DOS. (If you can't beat 'em, join 'em.) Of course, Novell later bought DR-DOS and made a lot of improvements. (But it was Caldera/Lineo who gave up on it.) > Most folks who got Windows got it as the next step beyond DOS, and > wanted to simply install it and run it. They did not want to first > install a flavor of DOS and then install Windows on top of it. It's the same kind of thing already. Win9x still had a separate DOS, and I think it even still ran "WIN.COM"! But it's just (barely) hidden where you think it's one single product (which just isn't true). > And then, as now, people generally bought Windows PCs with the OS > already installed by the vendor. There were preinstalls of all kinds of OSes, even OS/2. Heck, don't forget that some versions of OS/2 could run Windows (3.x) as a subsystem. Microsoft was still working on (and selling) all three OSes, at the same time, for many years. Heck, couldn't OS/2 boot any DOS, and not just MS-DOS [sic]? > I remember the early days when the PC was first out, and MSDOS/PCDOS, > Digital Research CP/M 86, and the UCSD P-system were all fighting for > a chunk of the PD market. MS won. The others lost. Deal with it. PC-DOS was far cheaper, AFAIK. Not sure about other advantages or disadvantages. >> They wouldn't even fix NTVDM bugs for Quake (from id Software, >> compiled for DOS via DJGPP) because "NT wasn't for games"! > > MS was focused on business users (and still is - Win10 is very much > geared to the Enterprise market ). NT was aimed at the business > desktop. Part of the problem from an OS perspective was that games > for platforms like DOS assumed they were the only program running and > owned the hardware, and would write directly to the hardware to get > performance. That's a no-no in a multitasking OS. It took a while > before MS realized that gaming was market and money could be made in > it, and did things like implement Direct-X to provide OS modulated > access to the hardware that games needed. I'm not talking about bad assumptions. I'm talking about explicit bugs that MS refused to fix. So Quake ran just fine under Win95, but it wouldn't run at all under NTVDM. Microsoft just didn't care. Of course, soon after that, all the following id Software games were "Windows only". Gee, I wonder why. Speaking of "business", Valve doesn't seem interested in Windows 8 and its exclusive App Store (nor the royalties they'd have to pay). This is probably why they're working so hard on SteamOS (Linux-based). ------------------------------------------------------------------------------ Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
