How to get OS9 v. 3 onto real floppies

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.

  1. download OS-9 from sourceforge
  2. download os9.exe
  3. download dskfix.qbs
  4. unzip everything. WATCH OUT for long filenames under old-fashioned DOS.
  5. format a pair of 360K disks under OS9
  6. use dskfix.qbs to "fix" the virtual disk files.
  7. os9 <drive> -w <dskfile> to write dskfiles to real media
  8. test disks by booting them.

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! :-)