[Coco] Nitros9 Boot Process

[Robert Gault]

To All,

There seems to be considerable confusion about OS-9/NitrOS-9 on floppies vs RGBDOS/HDBDOS hard 
drives and .vhd images and the boot process.

With just OS-9, there is a kernel and an OS9Boot file that are both on the floppy. Within the kernel 
is a Boot module that assumes you boot from the floppy and that this is where you will find the 
multiple module OS9Boot file.

With RGBDOS on emulators with .vhd drives and RGBDOS/HDBDOS with real hard drives, you assign one or 
more of the 256 Basic drives as an OS-9 boot drive. You use a Basic program LINK.BAS (at least with 
RGBDOS) which modifies LSN0 of the OS-9 portion of your hard drive so that it points to OS9Boot on 
the "floppy" in the Basic partition of the hard drive.
What this means is that you can boot into OS-9 from the hard drive or .vhd image without any 
floppies required.

You can also use a module and descriptor installed in your OS9Boot file (or just load then from 
CMDS) that permits direct access to the "Basic floppy" on your hard drive / .vhd image. That means 
you can change the content of your OS9Boot file without using a "real" floppy which then gets backed 
up to the hard drive under RGBDOS/HDBDOS. You will still need to use LINK.BAS as the size of your 
OS9Boot file may have changed.

You can read about RGBDOS at
http://aaronwolfe.com/robert.gault/Coco/Downloads/Downloads.htm
Some of the tools in this package for .vhd images may also be included in the VCC package and Bill 
Pierce's packages.
Certainly Cloud-9 must have docs and tools for use with HDBDOS on real hard drives.

Robert