When John Collyer took down his 6309 emulator page, it left a giant gap in the OS-9 version 3 project. Without his extended "dskini" utility, it is very difficult to copy the distrubution virtual disks onto real media.
Here is how I do it. This assumes that you have a real CoCo and that you have a PC with a 5 ¼ inch disk drive.
The problem the qbasic file fixes is this: OS9.exe gets confused about virtual disks that aren't the same size as the real media. IE a 360K virtual disk has to be 360K long. The distributed .dsk files for OS9 v. 3 end where their data ends. The current disk 1, for example, is about 335K. This simply fills up the "blank" bytes of the virtual disk.
(I used qbasic for 1 reason: It's what's included in DOS 6. If I
have to use BASIC under DOS, I prefer gwbasic. What, you're a coco user
and you don't remember BASIC? Don't lie! :-)