I wonder if the problem outlined above is occuring because I am a) using DOS 6, and b) using a DVD-RW disc. The disc has been written to more than once. I'm not sure if that makes a difference. The optical drive I'm using is a DVD-ROM reader.

it is some problem with the cd/dvd disc , I had similar strange things happen with bad burns or discs that DOS doesn't like

keropi wrote:

it is some problem with the cd/dvd disc , I had similar strange things happen with bad burns or discs that DOS doesn't like

OK, thanks a lot for the info. Apart from this strange DIR problem, my DVD-RW discs have served me well, and I'm pleased that they've lasted for as long as they have. I find it useful to download stuff from the net on my main machine, burn it on the DVD-RW disc, then use that disc on my DOS machines.

It sounds silly but have you verified that your file tree structure actually matches what you think? I've had issues with CD burner programs that automatically create a folder on the drive and will put all the stuff you copy onto the disc it into this folder rather than the discs root.

tl:dr

is your file structure:
d:\myfolder

or is it
d:\myfolder\myfolder

probably not the reason but it caught me out in the past.

I've double-checked both of my DVD-RW discs, and the structure is definitely what I think it is. That is to say, it's
d:\myfolder1 d:\myfolder2 etc...

Rather than
d:\someSubFolder\myfolder1 d:\someSubFolder\myfolder2

I had some similar problems in the past using a disc with more than one sessions. Also I remember I tried a dvd-rom drive on my 286, connected to a sound card's IDE controller, and it worked fine, but sometimes it wouldn't recognise all the directories.

Pay attention to the word I'm using. Folder is a windows 95 and later thing... We're using dos, and it has only directories.... 😜