China DOS Union

Now Grub supports directly booting DOS with chainloader /io.sys. Is there a consideration to use GRLDR to make an MS-DOS 7.10 installation program under Windows 2K/XP, and support the situation where the primary partition is NTFS?

[ Last edited by brglng on 2006-8-2 at 09:34 ]

io.sys cannot find msdos.sys, config.sys, command.com, and autoexec.bat on NTFS, so the DOS startup on NTFS still cannot be completed.

Just put msdos.sys, config.sys, command.com, and autoexec.bat in the first Fat32 partition.

Then io.sys can also be placed in that fat32 partition, which is not called installing on the ntfs partition.

I didn't say to install on an NTFS partition. I just said that it supports the case where the primary partition is NTFS. After all, DOS doesn't support NTFS, but through GRUB, DOS can dual-boot with 2K/XP when the primary partition is NTFS.

It's a bit like the recovery console.

This is completely different from the fault recovery console. Although DOS does not support NTFS, it can start DOS on a FAT32 partition using NT Loader and GRLDR. I have tried it. My hard drive has 5 partitions. The first 4 are all NTFS, and only the last one is FAT32. I put io.sys, msdos.sys, command.com, autoexec.bat, config.sys all in this partition, and then use chainloader (hd0,7)/io.sys of GRLDR to start DOS normally! Making this installation program should be very meaningful, which can let many people with NTFS primary partitions use DOS, which should be very good for promoting DOS...

[ Last edited by brglng on 2006-7-31 at 09:32 ]

Thanks to brglng for the reminder! I didn't expect that GRUB4DOS can be used like this.

This means that for a Win98 system that has already been installed on a logical drive in an extended partition, GRLDR can be used to boot it.

In addition, this also suggests that if you previously installed Win98 on a primary partition, and now directly copy this partition to a logical partition, then convert the file system of the primary partition to NTFS, or hide all FAT partitions on the primary partition. At this time, the Win98 on the logical partition can still be booted by GRUB4DOS, because the logical partition will be recognized as the C: drive by Win98.

The above is about using GRUB to boot Win98 that has been installed on a logical drive. Furthermore, you may be able to install Win98 on a logical partition! Usually, the Win98 installation program requires that there must be a primary partition in FAT format, because the Win98 installation program needs to place files such as IO.SYS on the primary partition.

Using the disk emulation technology of GRUB4DOS, before installation, you can temporarily emulate the logical partition as a primary partition to allow Win98 to be successfully installed on the logical partition (at this time, Win98 has treated this partition as a primary partition). After the installation is complete, there is no need for disk emulation. As mentioned earlier, you can directly use GRUB to boot Win98 on the logical drive. If this is feasible, this will be another way to install Win98 under Windows 2000/XP.

Yeah! I think it should be okay～! io.sys only looks for system files on the C drive, and it doesn't care whether the C drive is a primary partition or a logical partition!

In addition, I also tried using sys to transfer DOS system files to a logical partition, and then I can use chainloader +1 to boot DOS! That means installing Windows 98 might not need disk emulation at all, and it can be installed directly!

According to my machine, if I boot to DOS with a boot disk, and then use sys a: c: (here c: is (hd0,7)), and then configure in menu.lst as chainloader (hd0,7)+1, I can boot DOS! Maybe DOS doesn't need an MBR, and Windows 98 is too.

But all the above premises are: the system files required for booting must be on the first Fat partition! It can't be the second or the nth (n>1)! Because DOS only cares about the C drive!

[ Last edited by brglng on 2006-7-31 at 12:23 ]

No one is supporting? I'll support myself~

Indeed, MS-DOS 7.1 only recognizes drive C:, regardless of whether this partition is a primary partition or a logical partition. It can even boot from drive C: on the second hard disk (as long as there is no FAT partition on the first hard disk).

In addition, if DOS is booted from a floppy disk (including a virtual floppy disk), it only recognizes drive A: and not others.

I remember that I once tried to change the identity and boot record of an NTFS primary partition to FAT32 in a virtual machine, and placed the IO.SYS file on this primary partition. As a result, I really booted to the DOS prompt - although it completely skipped other boot files, but placing them on the first FAT partition solved the problem. However, since directly changing the identity of the primary partition is dangerous, this method is not practical. Of course, now GRUB4DOS can completely avoid this danger and is much more practical. However, since GRUB4DOS/GRLDR is not a file included in MS-DOS, you can consider trying to make a special installation version of MS-DOS 7.10, which is specially used to solve the installation of DOS on hard disks with relatively complex partition situations.

If this thing is developed, it should have strong practicality. Now many people are using the NTFS file system.

To say that grub is not a file included in MS-DOS, then doslfn, ctmouse, vide-cdd.sys and so on are not either, but they are still included.

I just think that making such an installation program can let many people who dare not install DOS because the primary partition is not fat32 use the full version of DOS. This is undoubtedly a very good measure to promote and popularize DOS! I myself don't have time and my programming level is relatively poor, so I have to ask all the experts! :p Even I think that the two versions of the installation program can be integrated, and when installing, automatically judge the installation environment and partition situation, and configure the system according to the actual situation, then it will be better!

In addition, doslfn should be able to be updated to version 0.40b! vide-cdd.sys should be replaceable with qcdrom... Actually, the drivers for USB devices can all be included. (Personal opinion)

In addition, I think some assembly expert can write a boot program for guiding io.sys in NTFS, and then make it into a boot sector file to be called in boot.ini. In this case, io.sys and ntldr need to be placed in the same partition.