China DOS Union

The same piece of hardware, the C drive is Fat32 with XP installed, and the extended partition D drive is Fat16 with DOS installed. Now I mainly want to ask for correction on the way to boot the DOS in drive D.

The first one:
title DOS
map --in-situ (hd0,4)+1 (hd0)
find --set-root /io.sys
chainloader /io.sys

The second one:
title DOS
map --read-only (hd0,4)+1 (hd0)
map --hook
chainloader (hd0,4)+1
rootnoverify (hd0)
map --harddrives=1

Which one of the above is correct, or is there a better way to write it? Please be corrected by the experts! Learning...

The second one, why use --read-only write protection? Is it to prevent virus writing? The last sentence of setting the number of hard disks to 1 is also unnecessary. In case you have two hard disks, won't the second hard disk be inaccessible?

--in-situ is generally not necessary. You don't need this when booting DOS. This option is designed to deal with Win98.

It seems that this is better:

title DOS
map (hd0,4)+1 (hd0)
map --hook
find --set-root /io.sys
chainloader /io.sys

If booting Win98, you must use --in-situ.

Under the command line, the following can start DOS:
grub>map (hd0,4)+1 (hd0)
grub>map --hook
grub>find --set-root /io.sys
grub>chainloader /io.sys
grub>boot

Under menu.lst, the following cannot start DOS; it will return to the boot menu. At this time, if you select the XP item, it actually enters DOS.
title DOS
map (hd0,4)+1 (hd0)
map --hook
find --set-root /io.sys
chainloader /io.sys

[ Last edited by e98123 on 2008-6-23 at 12:22 PM ]

It is absolutely impossible to boot XP because disk emulation is ineffective for XP.

Can't this work,
chainloader (hd0,4)/ntldr

Originally posted by Jneny at 2008-6-24 07:52:
Can't this be done?
chainloader (hd0,4)/ntldr

No.

Originally posted by e98123 at 2008-6-22 18:07:
The same hardware, the C drive is Fat32 with XP installed, and the extended partition D drive is Fat16 with DOS installed. Now mainly want to ask for correction on the way to boot the DOS on drive D

First kind:
title DOS
map --in-situ (hd0,4)+1 (hd0)
...

I have replied on Wuyou.
You can try the following menu.