[Coco] The difference between /SD0 and /D0

William Astle lost at l-w.ca
Wed Nov 5 16:56:07 EST 2014


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.

On 14-11-05 02:45 PM, Bill Pierce via Coco wrote:
>
> I was under the assumption that the CocoSDC was a WD1773 emulation, therefore /d0 should work on it as an RBF/wd1773 descriptor. I may be wrong in this assumption, as I don't have the SDC myself, but I thought that was the whole reason it was built.
>
>
> Bill Pierce
> "Today is a good day... I woke up" - Ritchie Havens
>
>
> My Music from the Tandy/Radio Shack Color Computer 2 & 3
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>
>
>
> -----Original Message-----
> From: Robert Gault <robert.gault at att.net>
> To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
> Sent: Wed, Nov 5, 2014 9:20 am
> Subject: Re: [Coco] The difference between /SD0 and /D0
>
> Well I would not call it "right". :) What you are seeing should never happen as
> there are two different sets of drivers for /SD0 and /D0. I have a different
> pak, microSD by Roger Taylor, which has no problems handling pseudo drives on
> the microSD, drives on DW4, hardware hard drives on a Ken-Ton interface, and
> hardware floppies all at the same time.
> There is no way I can test any of the SDC software without hardware. I also
> can't distinguish between software failure or SDC hardware failure.
>
> Based on the NitrOS-9 source code, your OS9Boot file should include, rbsuper,
> llcocosdc, and sd0 for the SDC; rbdw, dwio, and x#s for DW4; rb1773, and D#s for
>
> floppies. These different sets should be invisible to each other.
> If the SDC wants to emulate both floppies and hard drives, it ought to use the
> SD# descriptors for both and distinguish the format in the descriptors.
>
> What do you see with
> ident OS9Boot
>
> ===============================
> Yes ed is the terrible editor that came with OS-9. There are several third party
>
> editors available. What you pick will depend on whether you want to write
> letters and document or source code.
> I use scred very often as I normally write source code.
>



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