virtualbox.org

Recently I got a new PC running W7-64 (8-core AMD FX-8150, with 16Gb), which meant that I no longer had access to many of my old 16-bit programs, most notably Vern Buerg's LIST.COM - yes, I still use this little gem, ZBLIST is not (yet) up to scratch. So given that I still had a bunch of XP's lying around, I tried VBox, which works very well, I've even managed to install, just for fun, my old copy of IBM's PC DOS 2000 on it.

However, I have a problem accessing the disks of the host with LIST.COM, which may be a problem of VBox, or of LIST or the interaction between the two.

If I open a command prompt on the XP box, and CD to the host-directory I want to see, a subsequent "LIST" will not show anything. However, if I do a "LIST filename" it works without problems - on a normal XP system entering "LIST" will show the directory and this has always worked OK.

Any clues would be appreciated.

I assume you mean that you're using the Guest Additions shared folder feature with your guest XP.

Although I don't remember it ever being officially acknowledged, lack of support for 16 bit apps accessing GA shared folders is something that others have reported as well. If you want the 16bit app to work properly then you would need to configure a proper network shared folder, not a GA share. It's really quite easy to do, the only downside is that the shared host folder is theoretically visible to any network connection, not just virtual networks. No problem as long as you don't keep anything sensitive in there (e.g. I'd keep your plans for world domination somewhere else ).

And how would I create a properly shared folder?

Not that it would be very useful, as, IIRC, LIST.COM contains code that prevents it from accessing networked drives...

FWIW, the strange thing is that another program also fails on full wildcard use i.e. "program *.ext", but does work with limited wildcards, i.e. "program a*.ext"

cloggie wrote:And how would I create a properly shared folder?

That's a networking question, not a VirtualBox question. That sort of info is easily available in the wider web.

cloggie wrote:Not that it would be very useful, as, IIRC, LIST.COM contains code that prevents it from accessing networked drives...

Well now. You seem to have eliminated the only interpretation that made your original Q make sense. Apart from USB (which you didn't mention), a VM can't access a host drive by any means other than a network share, so naturally apps run inside the VM can't access it either.

cloggie wrote:another program also fails

Unless you can provide specifics then I can't comment.

mpack wrote:

cloggie wrote:And how would I create a properly shared folder?

That's a networking question, not a VirtualBox question. That sort of info is easily available in the wider web.

I tried to find this info, and the only thing I did find was using "net use", but that does not show up any of the disks on the host, unless they are already shared with VBox, and assigning another drive letter via "net use" to a disk that is already shared does not stop the problem from happening.

mpack wrote:

cloggie wrote:Not that it would be very useful, as, IIRC, LIST.COM contains code that prevents it from accessing networked drives...

Well now. You seem to have eliminated the only interpretation that made your original Q make sense. Apart from USB (which you didn't mention), a VM can't access a host drive by any means other than a network share, so naturally apps run inside the VM can't access it either.

Then why, oh why, can LIST.COM access individual files on the host drive if it is shared with VBox via the VBox extensions?

mpack wrote:

cloggie wrote:another program also fails

Unless you can provide specifics then I can't comment.

It's an old IBM program, a PC version of its z/OS SuperC file compare program. It has no restrictions on accessing networked drives, but like LIST it refuses to accept full wildcard arguments.

FWIW, M$ Virtual PC has, despite being the garbage that it is (I lost everything I painstakingly copied from my old PC already twice for no apparent reason), no problems with LIST or SuperC accessing "net use"'d drives on the host.

"Net use" doesn't create a share, it just maps a drive letter to a share.

To create a share on a Windows host you right click it on a folder and tick the "Share this folder" checkbox. Then you make sure that guest and host belong to the same domain or workgroup. There are other details - really, you are best off googling for that standard networking stuff.

cloggie wrote:Then why, oh why, can LIST.COM access individual files on the host drive if it is shared with VBox via the VBox extensions?

I've given you the facts. Its up to you to find out why your perceptions seem to conflict with them. I can't do that for you from here.