[Coco] Double sided disk usage with the Vavasour or Collyer Coco3 emulators?

[Robert Gault]

Is there anyone on the list who is familiar with the Jeff Vavasour Coco3 v1.6 or 
1.71 emulators or the John Collyer Coco3 v1.91 emulators? I have been trying to 
get these to work with double sided 80-track disk images with no success.

Far as I have been able to discover, the JVC disk format does support double 
sided disk images: http://tlindner.macmess.org/?page_id=86
However, any .dsk images I've created with the required headers have been 
treated as single sided.
I'd like to run, or test, the NitrOS-9 builds on these programs but no double 
sided disks have been correctly read.