[Coco] Newest Nitros9 and B&B

Robert Gault robert.gault at worldnet.att.net
Tue Aug 1 20:30:59 EDT 2006

leonard wrote:

> Ok...Another question.  If I install the boot module, then all I need is the
> device descriptor?  Like h0, h1?  I do have them, but since the Os-9
> operating system has been optimized for the 6309 I assumed the software for
> the B&B needed to be as well.  I do own the original disks for the
> controller.  When the superboard becomes available I won't have to worry
> about any of this stuff.  Hallelujah!!  I'm frothing at the bit for that,
> but for now I have to work with what I have.  It will be worth the wait I'm
> sure!  The good thing out of all this is that I learned how to get a dsk
> image onto a real coco disk and learning is what it's all about for me.
> Thanks to everybody for all the help.
> Leonard
Joel has given you a perfect answer to the first part of your question. 
Regards 6309/6809, you normally don't need to worry about that, as 6809 
code runs on a 6309 system. However, one of the few modules likely to 
cause trouble is a disk driver.

If you look at the driver for Disk Basic in the "Unravelled" series, you 
will see that the NMI returns from the I/O loop because the correct 
address was manually placed on the stack. Well the size of the stack 
changes going from the 6809 to 6309 in native mode; the mode for 6309 
NitrOS-9. That means the B&B driver may need to be modified for 6309 
native mode use.

The NitrOS-9 project has B&B drivers in the 3rdparty/drivers directory. 
The modules are not part of the distribution. I have not looked at the 
source code and don't know if it needs or has been modified for 6309 
native mode operation. It would be easy to download a snapshot of the 
source and compile it after making any needed changes.

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