[Coco] The difference between /SD0 and /D0

Brett Gordon beretta42 at gmail.com
Wed Nov 5 17:19:22 EST 2014


William:

Are the d# descriptors and sd# descriptors really mutually exclusive?
I'm now under the impression that NOS9's sd descriptors are really
access different logical drives ( the two possible LBA ones) than the
regular D# drives.  Darren:  are the LBA mode drives different than
the FD drives on the SDC?  or are the FD drives mapped to the LBA
drives somehow ?    IF they are different drives, I don't see any
reason for not including them in your OS9BOOT.   My first message to
Nick was botched... I thought the llsdc drivers for NOS where just
fancy versions of rb1773



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.
>
>
> 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
>> https://sites.google.com/site/dabarnstudio/
>> Co-Webmaster of The TRS-80 Color Computer Archive
>> http://www.colorcomputerarchive.com/
>> Co-Contributor, Co-Editor for CocoPedia
>> http://www.cocopedia.com/wiki/index.php/Main_Page
>> E-Mail: ooogalapasooo at aol.com
>>
>>
>>
>>
>> -----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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-- 
Brett M. Gordon,
beretta42 at gmail.com


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