China DOS Union

Strongly requesting a "sticky" and a "systematic" answer to "WINDOWS9X is actually DOS"

Since everyone considers this question a "room-temperature" question, why not make a systematic sticky thread on this question??? I think this is also at least one basic "component" of a DOS forum!!!

I personally still have some extended confusion on this issue, please clear it up together:
1. What are the differences between DOS, 9X, and NT (NT4.0, 2000, XP)?
In the thread “WINDOWS9X is actually DOS” they all say 9X is DOS, but it still isn't systematic enough; there have also been questions asking about the relationship between NT and DOS, but no one has answered yet.
2. The DOS our forum advocates is DOS in development, but the DOS we keep talking about seems to be that “old guy,” that thing inseparable from “real mode.” To be honest, what exactly is “real mode”??? Could someone explain it in detail???
3. Can DOS drivers be used under Windows? (especially in the 98 DOS window)
4. In XP's F8 menu there is an item "98se-DOS". Unlike in 98 where it can be used directly, here you still have to put in the system CD before it can be used. Why? Is there any way to make it “no-CD”???

As for the relationship between DOS and WinNT/2K/XP, take a look here:
http://newdos.yginfo.net/upload/newdos.txt

Why do we say Win9x is a GUI program under DOS? Let me give some reasons:

1：To start the Win9x GUI, you first have to start DOS. After DOS starts, there are two ways to enter the Win98 GUI: automatically and manually. The former is to set BootGUI=1 in MSDOS.SYS, while the latter is to use the WIN command. This is exactly like the relationship between Linux/FreeBSD/Unix and the X-Window GUI/server. Under Linux/FreeBSD/Unix, there are also two ways to start the X-Window GUI, manual and automatic. One is automatic, and the other is to enter it manually with the startx command. Because the kernels of DOS, Linux/FreeBSD/Unix, etc. are all character-based, they all use commands to enter the GUI.

2：The Windows 9x GUI, namely Windows 4.x, developed all the way from Windows 1.x, 2.x, and 3.x. Among them, Win1.x wasn't even as capable as DOSSHELL, Win2.x was about the same as DOSSHELL, Win3.x was more capable than DOSSHELL, and by 4.x there's even less need to say. But anyone who has worked on MiniWin knows just how similar the various versions from Windows 1.x to 4.x are. It is only that each version had a fairly large functional expansion over the previous one, while still being part of the same continuous line.

3：The Windows 9x GUI itself also says that it can only run under MS-DOS. If it runs under other DOSes or lower versions of DOS, it will show messages like the following:
This version of Windows does not run on MS-DOS 6.x or earlier. (Win95 WIN.COM)
This version of Windows does not run on MS-DOS 7.00 or earlier. (Win98 WIN.COM)
This version of Windows runs only on MS-DOS 8.00. (WinME WIN.COM)

Cannot run Windows with the installed version of MS-DOS.
Upgrade MS-DOS to version 7.0 or higher. (Win95 VMM32)

Cannot run Windows with the installed version of MS-DOS.
Upgrade MS-DOS to version 7.1 or higher. (Win98 VMM32)

Cannot run Windows with the installed version of MS-DOS.
Upgrade MS-DOS to version 8.0 or higher. (WinME VMM32)

In fact, taking Win98 as an example, it can run under MS-DOS 7.0, under MS-DOS 7.10, and also under MS-DOS 8.0. It just cannot run under other DOSes. Win95 is the same.

4：One characteristic of the DOS IO.SYS kernel is that it is small in size (compared with Linux/Unix etc.), but highly extensible. For example, by loading HIMEM, EMM386, CWSDPMI, DOSLFN, etc., it can drive XMS memory, EMS/VCPI memory, DPMI memory, long filenames/VFAT, and so on. VCPI or DPMI among them lets the DOS kernel enter DOS mode under 32-bit protected mode. And the Win9x GUI is precisely what uses DOS drivers such as DPMI and VFAT and provides some WIN API to enter its operating interface. In fact, there are many programs under DOS that can accomplish these functions, but the Win9x GUI is the most powerful one among them (thanks to MS's strength). Through these drivers, Win9x expanded DOS and made the DOS world richer and more powerful.

5：Some people say Win9x established a new kernel instead of using the DOS kernel, and this is obviously wrong. Let me use a few examples to explain:
1）If it really established a new kernel, then the original DOS kernel would already have been replaced by the new kernel. In that case, once the so-called Win9x GUI kernel started, it should be impossible to exit it, because under that assumption the DOS kernel would already have been replaced, leaving only the Win9x GUI kernel. But in fact, after “Shut Down Computer”, the Win9x GUI can directly return to the pure DOS command line by entering MODE CO80, without needing to reload a new DOS kernel to replace the so-called Win9x GUI kernel;

2）If it established a new kernel to replace the old kernel, then all the programs or drivers already loaded in the original old kernel would become invalid, because the kernel would have been rewritten, which would be equivalent to rebooting the computer once and loading a new operating system, for example BasicLinux is like this. But in fact, Win9x GUI is obviously not like that, and is merely loaded as a GUI program under DOS.

3）If a new kernel were used to replace the old kernel, then the various services provided by the old kernel would be useless to the new kernel, because once the kernel was rewritten, any functions in the old kernel would be cleared from the system and replaced by those provided by the new kernel. The reason X-Window is called a GUI rather than an OS is precisely because it does not do this, and still calls the functions of the operating system (such as Linux/Unix/FreeBSD etc.). And what about Win9x? Taking disk allocation as an example, Win3.x and Win9x both rely on DOS. For example, if I start the Win98 GUI under MS-DOS 7.0 (which does not support FAT32 drives) and under MS-DOS 7.10 (which does support FAT32 drives), the results are also different: because MS-DOS 7.0 does not support FAT32 drives, after using it to start Win98 you still cannot see FAT32 drives; and because MS-DOS 7.10 supports FAT32 drives, after using it to start Win98 you can also see FAT32 drives.

4）Why does the DOS window in Win9x have such good DOS compatibility? It is because it uses the DOS kernel. As for WinNT/2K/XP, since they do not have a DOS kernel, they can only rely on virtualization to run DOS programs (that is, the “DOS window” in WinNT/2K/XP). But although MS has put a great deal of effort into improving the compatibility of this DOS virtual machine in WinNT/2K/XP (that is, NTVDM), its compatibility is still far inferior to the DOS window in Win9x up to now. Why? The reason is very simple: Win9x uses a standard DOS kernel, while WinNT/2K/XP does not.

Do you all think this is explained clearly enough?