China DOS Union

As the title says.

How do I use it? How do I configure it?

Mine always gives errors!

Thank you for your interest in GRUB4DOS. At present there is no support for PC DOS yet. It will be supported in the future, but work on this issue has not started yet. The implementation of some functions is not a priority and has been placed later in the queue. For example, CDROM and ISO booting: the issue itself involves a standard maliciously polluted by Microsoft (bootable CD-ROM specification), so it is very tricky to handle and can only be put at the lowest priority and solved last. As for support for DOSes such as PC DOS, because they have relatively few users, they also do not have very high priority. Also, for example, NTFS support has already been frozen. This is because Microsoft maliciously broke GRUB4DOS's calling of the NT bootsector, making this support unstable, and they can continue to break it at any time, so we can only freeze support for NTFS (that is, no further development, and no more handling of BUG reports related to NTFS). In any of the above situations, everyone can provide patches; even for frozen items, patches can still be accepted.

Patches like this: grub-0.97-patch7-scdrom
How should they be applied?

I recommend that you use System Commander
but it itself can only be installed on a partition with a FAT file system type.

scdrom has also been frozen. This is mainly because the scdrom module cannot perfectly solve the CDROM boot problem; it only solves part of the CDROM boot problem. Users have reported that this module is actually unusable under the current GRUB4DOS, so it is being prepared for deletion. If I have time in the future, I will consider rewriting the CDROM driver.

Those patch files you saw are accessed automatically by the compile file, so there is no need to handle them manually. Study the compile file and it will become clear. This requires some understanding of LINUX.

Question for tinybit:
We know that writing this in menu.lst:

title Boot from HDD
rootnoverify (hd0,0)
makeactive
chainloader +1

title Boot from CDROM
map --mem --read-only (hd0,0)/boot/cd.vfd (fd0)
map --hook
chainloader (fd0)+1
rootnoverify (fd0)
map --floppies=1

title Boot from Floppy
chainloader (fd0)+1
rootnoverify (fd0)

means booting from the hard disk, CD-ROM drive, and floppy drive respectively. So is there some simple way to also write something in menu.lst so that booting from a USB drive can be achieved?

Originally posted by martin325 at 2006-4-20 03:01 PM:
Question for tinybit:
We know that writing this in menu.lst:

title Boot from HDD
rootnoverify (hd0,0)
makeactive
chainloader +1

title Boot from CDROM
map --mem --read-only (hd0,0)/boot/cd.vfd ( ...

That depends on what your BIOS recognizes the USB drive as. Generally, on some machines it is emulated as a floppy drive (fd0), and on others it is emulated as a hard disk (hd1) (assuming your computer has only one hard disk).

If it is recognized as (fd0),
chainloader (fd0)+1
boot

If it is recognized as (hd1),
map (hd0) (hd1)
map (hd1) (hd0)
map --hook
chainloader (hd0)+1
boot

Of course, there is another possibility: the computer has a floppy drive, and the USB drive is recognized as (fd1), but I have not run into this situation. If so,
map (fd1) (fd0)
map (fd0) (fd1)
map -hook
chainloader (fd0)+1
boot

Thanks to fujianabc for the reply.
Looks like the parameter settings for recognizing a USB drive depend on the BIOS.

Is there any kind of setting that can cover all three situations mentioned by fujianabc?

For a USB drive, there should be no universal method; it completely depends on what the motherboard emulates the USB drive as. The above three cases are emulating the USB drive as the first floppy drive, the second hard disk, and the second floppy drive.

My friend's computer has an NTFS C partition.
Right now I have copied the three files grldr, menu.lst, and winmedos.ima to the root directory of C:\.
Under this situation, how should I adjust things so that GRLDR can use grub-0.97-patch3-ntfs,
and make the computer successfully boot the virtual image boot file "winmedos.ima" from GRLDR?

I copied grub-0.97-patch3-ntfs, grub-0.97-patch4-emulation, grub-0.97-patch7-scdrom, and compile all to the root directory of C. After booting the computer, MENU.LST can start, but when I choose to boot from the image file in MENU.LST, the computer hangs. So depressing...

How large is the winmedos.ima file?

2.88 standard image file