Transferring Virtual Box Disk Image to CF Card

In vintage computing, one of the toughest aspects is the longevity, or lack there of, of old IDE hard drives. Also, many of my collector systems lack working floppy drives, which are sometime near impossible to find.

Instead of starting new every time, I have several images on my computer of MS-DOS installations. I transfer them to a CF card, which is then put into a CF to IDE converter, which is lastly placed in the system. Some older systems have BIOS that will automatically detect the change. Others, will need to be manually set up, which is a trickier process for another article.

I was unable to find a good guide online for transferring VirtualBox machines onto CF Cards, so without further wait, here is my guide.

Material Needed

• CF Card to IDE adapter: I have found StarTechs to be the most reliable You may need a Molex power adapter depending on the set up of your system.
• CF Card (size depends on needs, but I stay below 2gb for old systems) I prefer Transcends for price and they seem to work.
• Oracle’s Virtual Box
• Installation medium to install MS-DOS. If you do not have this FreeDOS is a good alternative

When Launching Your Virtual Machine

I’m not going to walk through the entire process of building a VM. I’m assuming readers have experience doing this. I do want to make a note.

Make sure to set Option for Virtual Hard Disk to (Pre-allocate full size). Also keep in mind that for the example of a 512mb card the actual size is 476mb. Set the preallocated to the actual size of physical medium you will use. (I usually do my drives at 470mb,)

Time to Transfer the VirtualBox Disk Image

1. We will need to convert the Disk Image to a raw *.img file. We will do this using the command prompt. This should be opened with administrator rights.

Navigate prompt to C:\Program Files\Oracle\Virtualbox
# The following input will clone your drive into an *.img file (Replace sourcedisk.vdi with the virtualboxes assigned disk and target.img with where you want the new image to save.  Include full paths if needed)

COMMAND FOR CLONING BELOW!!!

>  vboxmanage clonehd sourcedisk.vdi target.img --format raw

Now that you have your img file, you will need to write it to your CF Card. For this I’ve used Raspberry Pi’s Imager software, however you could also use Balena Etcher or another program.

Once you have cloned your img to the CF Card, you are now able to install it into your retro system using your CF Card to IDE adapter!