file sharing between Windows 10 host & DOS 6.22 guest

[mdavid]

Hi running Windows 10 as host and installed DOS 6.22 in VirtualBox.
In the DOS 6.22 VM VirtualBox window I tried to share folders both from: Devices > Shared folder settings and
Devices > Insert Guest Additions CD image - this doesn't continue to install, there's no error messages, but unable to see any Windows folders.
What do I need to do to share folders between Windows 10 and DOS 6.22?

Thanks for any help
David

[socratis]

Sharing with DOS? That's not an easy task to do at all.

First of all, for Shared Folders to work you need Guest Additions (GAs), and there are no GAs for DOS.

Second if you were really masochist and wanted networking in DOS, chances are that you won't be able to talk to anything more than Win3x.

What do you want to share? And why if I may ask?

[mdavid]

Hi Socratis,
Thanks for your reply.
My problem is I need to run some legacy DOS software - not games - on Windows 7 and 10. I've been thru vDos, DOSBOX and FreeDos, but none of them are the full implementation of DOS and my client wants something as close as possible to the original, so it looked like VirtualBox with DOS 6.22 guest was the best solution, but to run the software I need to share the files on the Windows host machine, do you have any idea how I can do that?

Any help much appreciated
David

[socratis]

I need to share the files on the Windows host machine, do you have any idea how I can do that?

There are a couple HowTos such as Set up a DOS VM with networking (and shared folders) and a couple more in the HowTo and Tutorials » Other Guests area, but I haven't personally tried them.

[mdavid]

Hi Socratis,
Would it not be possible to create a Virtual Hard Disc from the DOS guest and copy files from windows host?
Can I mount a folder in the VirtualBox?
Thanks
David

[mpack]

Yes, you can create a virtual hard disk on the host (*). However the host has no access to the contents. A VM is a second PC, so you are restricted to file exchange methods you'd be able to use if you had the two PCs side by side on a bench. Only in your case one of those PCs doesn't support networking, doesn't support USB, and only supports CD drives if you install the drivers (**).

Are you using terminology correctly? Do you really need to share files on your host, or do you simply want to copy files into the guest, one time only? Because in the latter case, an ISO image is about your only practical option.

FreeDOS is going to be your best bet at achieving modern networking standards. Trying to do it with DOS 6.22 is IMHO a waste of time - not only did the networking drivers not exist, the concept didn't exist. p.s. Hence my opening question: I find it hard to believe that any legacy software requires features that didn't exist when the software was created.

(*) Actually, a disk imaging app such as MagicISO will certainly support FAT16 VDI drives, I don't know if it allows write access though, and certainly not while the VM is running.
(**) Back in the day the standard way to get files from PC A to PC B was file transfer software.

[mpack]

Actually, one correction. I had forgotten about the v6.x "Virtual ISO" feature. That is almost purpose designed for conveniently getting files into a DOS guest. Of course being an ISO it will be read only while the VM is running.

[mdavid]

Thanks very much for your comments, I understand that FreeDos in VirtualBox is the best way to go in terms of a stable connection with the Windows host and sharing folders.
I want to run the legacy DOS software on my Windows 10 pc, initially there seemed to be so many options, but in the end there's no solution that ticks all the boxes.
You say I can use the "Virtual ISO" feature, could you clarify "read only", if the legacy software updates/outputs files would I be able to access them in the Windows host?
Your help's much appreciated.
Thanks
David

[Martin]

The VirtualISO featrure only allows files creted on the host to be read into the guest.
If the files created by your legacy software are not larger than 1.4 MB you could use virtual diskette images.
From the DOS guest you would read and write the files like on a physical diskette.
There are many tools available to read and write diskette images on Windows 10.

[mdavid]

Hi Martin,
Just so I'm clear VirtualISO is not file sharing - I need to physically copy the files/folders between guest & host each time?

Thanks
David

[Martin]

Yes, both the virtual CD/DVD and the virtual diskette drive cannot be used for "sharing".
The VirtualISO feature takes specified folders on the host and creates a virtual CD (read-only) which can be mounted and read in the guest.
To use a diskette image to transfer files from the guest to the host you would need to copy these files in the guest to the diskette and then "eject" it and open the diskette imaqge file on the host to get access to the files.

[mdavid]

Thanks very much for all your help - beginning to see the light, at the moment it's shinning on FreeDos, hope that's the one.

[mpack]

To be clear as well. If you want two working PCs to access the some folder at the same time then the only technology I know of which allows that is a network share (and being a VM doesn't exempt that PC from the expectations of the guest OS, so magic solutions I'm afraid do not exist). You'll be constrained in that DOS shares date from an era long before plug and play or the OS handholding you through the network setup, so you'll have to read the FAQs and even then may need to Google for more.

[mdavid]

Sorry, not expressing myself very well.
I want the 2 PCs to have access to the same folder, but not at the same time. Just that any changes made to a file will be visible from both the host & guest OS.
So if I don't want to use a network share I'd need to close the guest connection before opening the file on the host OS is that correct?

[jorgensen]

Here is what I did to ´share´ files in a DOS guest.
Create a small fixed size Shareable vdi file, and attach it to the DOS guest and e.g. a Windows 7 guest.
Then you have a drive, where files can be moved around.
Unfortunately a Shareable vdi does not work properly with DOS, because the drive cannot be refreshed, so a reboot is required.
Of course the new disk need to be formatted, which is easy in the DOS guest with fdisk.