[Coco] OS9 vs RSDOS disks

[Bill Pierce]

Bob, this (for now) going to be exclusive to OS9. I just need to know how to ID asto whether a disk is OS9 or DECB. The program is for writing to and from DECB disks from OS9 (fd, hd, vhd etc) with a file manager so, if the user selects a drive, I can verify if the disk in the drive is os9 or rsdos. Of course it will error one way or the other, but then you have to deal with the error. I think if I use Mr Gault's method, it would be safe to assume if it didn't pass the test, then it's an RSDOS disk.
Here's a link to the blog for the new program

https://sites.google.com/site/dabarnstudio/hrsview

It should be in testing mode by next week :-)

Bill Pierce
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: Bob Devries <devries.bob at gmail.com>
To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
Sent: Thu, Jun 13, 2013 10:26 pm
Subject: Re: [Coco] OS9 vs RSDOS disks


Robert,

Your explanation of the LSN0 structure is great, but it only holds true with 
Single-sided disks. On a double-sided disk, the directory sector could 
possibly be on the other side of the disk, which, from the point of view of 
writing a DECB identifier, wuld open a large can of worms.

Regards, Bob Devries
Dalby, QLD, Australia

----- Original Message ----- 
From: "Robert Gault" <robert.gault at att.net>
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Sent: Friday, June 14, 2013 8:56 AM
Subject: Re: [Coco] OS9 vs RSDOS disks


> Bill Pierce wrote:
>>
>> Hi guys,
>> Is there a simple way to tell an OS9 disk from an RSDOS disk? Maybe 
>> something constant in LSN0 on the OS9 disk?
>> It would be nice to identify the disks through software
>>
>> Thanks
>>
>> Bill Pierce
>
> Bill,
>
> Unfortunately there is no sure fire method. What might work most of the 
> time is to see if there is a root directory in the correct location. If 
> there is, then the disk is at least formatted for OS-9 but might also be 
> formatted for Disk Basic.
>
> LSN0 bytes $08, $09, $0A are DD.DIR - address of starting sector of root 
> directory
>
> DD.DIR bytes $10, $11, $12 - indicate address of first sector of directory 
> listing
>
> First sector of listing for any directory
>
> bytes
> $00   $2E $AE
> $20   $AE
> These are the .. and . entries in any OS-9 directory but they are never 
> printed by the command dir.
>
> Robert
>
>
> --
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