[Coco] The difference between /SD0 and /D0

Aaron Wolfe aawolfe at gmail.com
Wed Nov 5 17:37:34 EST 2014


On Wed, Nov 5, 2014 at 4:56 PM, William Astle <lost at l-w.ca> wrote:
>
> Bill has it right here. Because the CocoSDC emulates the actual floppy
device, it can be accessed with drivers for the standard floppy controller.
It also has a mode where it can be accessed more directly without the
floppy geometry emulation ("LBA mode").
>
> Basically, the problem at hand here is having two different drivers
driving the same hardware. It doesn't matter what operating system you are
using, that is a recipe for confusion at best and more likely disaster.
>
> In short, this is not a bug in Nitros9 itself. It's a bug in the
particular setup that is in use. (Two drivers for the same hardware.)
>
> It seems to me that the LBA driver should work just fine on "normal"
images. After all, RBF itself doesn't have any notion of device geometry -
it just works with logical sector numbers so should be just as happy with
an LBA mode driver.
>
> It seems to me that the SDC "flavour" of Nitros9 should simply omit the
rb1773 and d# modules.
>

This sounds good to me.  Let the software control how the hardware is
presented and take responsibility for doing that sanely, if possible.  The
controller really shouldn't be burdened with this kind of thing IMHO.
There may be times when a user *wants* to talk to the SDC as a floppy
controller in NitrOS9.

$0.02
-Aaron


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