Create Bootable DOS floppy image

[asai]

Hi,
I am trying to make bootable floppy image files for use in Virtualbox. I have the files from the the MS-DOS floppies on my computer.

I have tried this:

dd if=/dev/zero of=floppy.img bs=512 count=2880
mkdosfs floppy.img
sudo mkdir /media/image
sudo mount -o loop floppy.img /media/image
sudo nautilus /media/image

Copied the files to the mount, then

sudo umount -l /media/image

Then I tried to start my DOS Virtualmachine in Virtualbox.
But it stops with error: "This is not a bootable disk"
What's wrong with the image file?

Ref this page: http://ubuntuforums.org/showthread.php?t=140762

[spcwingo]

If all you need is a basic DOS boot floppy to update a BIOS, you can download a FreeDOS based boot disk here. Extract it, then write it to disk with this command:

dd if=/path/to/FDOEM.144 of=/dev/fd0

I have used FreeDOS boot disks to update the BIOS on many of my machines.

Now, if this isn't the case at all, please post back with specifics of what it is you're trying to accomplish and I'll try to give you a hand to the best of my abilities.

EDIT: I didn't see the part about trying to run DOS under VBox. Still, if all you need is a DOS environment to run old programs/games try FreeDOS. You can read more about it here

[asai]

Thanks for your reply.

I have MS-DOS 4.01 on 4 .dsk file format images. These images I have succesfully extracted, and are now trying to make .img files of them. This I have accomplished with the command in my previous post. However, I want to boot from this image with Virtualbox. This doesn't work.

[spcwingo]

Have you tried to just change the extension? If that doesn't work just put the floppies back in your machine and use dd to extract the images. Example:

dd if=/dev/fd0 of=/home/asai/disk1.img

You could always just use the floppies under VBox...just mount your host drive.

[asai]

If I had a floppy drive I could, but I don't...
That's the reason why I would like to use image files to boot my virtual machine. The image contains all the system files needed to boot, but it doesn't have the boot record. Is this correct?
So, the solution is to get them into the image like bootable iso CD images...

[angry_johnnie]

Why not just download a floppy image?
or a cd iso image?

You can get DOS 7.10 from here. It has a lot of nifty features.

[lykwydchykyn]

Well it's been a few years from the DOS days, but if memory serves copying the files wasn't enough to make a bootable floppy. You had to run the "sys" command which I presume installed some sort of boot sector to the disk.

I don't know what a .dsk file is, but if the filesize is 1.4 MB then it's likely they are just straight images. There's no real standard file extension for floppy images, I've seen people use .img, .flp, .144, and other things. Where did these files come from?

[Chronon]

Or download a fresh .iso from the freedos site: http://www.freedos.org/freedos/files/

[matey3]

Well it's been a few years from the DOS days, but if memory serves copying the files wasn't enough to make a bootable floppy. You had to run the "sys" command which I presume installed some sort of boot sector to the disk.

I don't know what a .dsk file is, but if the filesize is 1.4 MB then it's likely they are just straight images. There's no real standard file extension for floppy images, I've seen people use .img, .flp, .144, and other things. Where did these files come from?

yeah lol, good old days...
I remember doing sys a: or use quick format command like format a: /q /s to put the system on the disk.

I remember downloading a linux boot disk once which came with this program (may be called flash?) I dont remember really but that .exe file would put the system on the disk and make the computer boot.
anyway you are right that DOS machines require a special boot disk where the system file go on specific location on the disk, whereas the linux you can just copy the files you need to boot with.
I also usd to visit bootdisk.com a lot I dont know if it still exits?

[lykwydchykyn]

anyway you are right that DOS machines require a special boot disk where the system file go on specific location on the disk, whereas the linux you can just copy the files you need to boot with.
?

Well, not really; with any OS you have to have a proper boot sector in place. GRUB or LILO take care of that for you in Linux, or for a floppy you'd use something like syslinux.