[Coco] Re: Dynacalc & Stylograph with Nirtos9 & CoHR 51X24

[Phill Harvey-Smith]

Leon Howell wrote:
>> Once you register you'll see the dragon downloads section on the left menu.
>> Files are VDK format - you can read them fine under MESS (its actually DSK
>> format with extra header info at the beginning).

Which for MESS is just as well, as MESS only recognises DSKs when 
renamed with the OS9 extension....well Nitros ones anyway.

I think the header was put there as DragonDos disks don't have an LSN0 
like Nitros ones do, and so need to know the disk geometry to know where 
in the file to find the directory track etc, this is what the header is 
there to provide.

For the curious, DragonDos does store the geometry info, in the 
directory track, which is track 20, backup on track 16, but of course 
for an image file the offset of this info will be in a different place 
for a double sided image.

> Found it. How do I extract files, or make a disk, from the .vdk, preferably in 
> NitrOS-9, but if not, ms-dos 3.2?

VCopy in the utilities section should do what you want. Alternatly I 
wrote a couple of little C programs that can add or remove the VDK 
header, perhaps I should integrate this into toolshead at some point ?

Cheers.

Phill.

-- 
Phill Harvey-Smith, Programmer, Hardware hacker, and general eccentric !

"You can twist perceptions, but reality won't budge" -- Rush.