[Coco] Nitros9 on a CC3 512k

[Gene Heskett]

On Sunday 28 February 2010, George Ramsower wrote:
> Finally I get around to play with Nitros9, build a boot disk on my XP box
>using Cocodisk from nos96809l2v030208coco3_80d.dsk and it has a problem.
> First, I used cocodisk to format the 720K 3.5" disk with 80 track, two
>sided. Then did the "Write to disk" to do this.
> The coco does boot and gets as far as the startup file and hangs.
> Rebooting with a working OS9 disk and looking at the Nitros9 disk reveals
>that the root directory appears to be intact but I cannot list the startup
>file or peer into the cmds directory. Error 247.
> I tried formatting a floppy on the coco and trying again but, with the
> same result.
>
> I would offer more info but don't what to tell you. Ask me questions and I
>will begin the discovery process as to why I'm getting this problem.
>
> Thanks,
>
>George

I have found that the default build does not properly identify the disk 
images format, and have had to edit it with a hex editor, changing the bytes 
at offset $10, and again at $41 I believe, to (if using the 80 track image, 
$07 at 10, and $03@$42). 

The formatted disk should be looked at in ded /d0@, the values at those 
locations noted, and the file edited with a hex editor to match and then 
rewritten to the real disk.  This area of the formatted disk is overwritten 
by the writing of the image, so the image has to match the original format in 
those two places otherwise the driver thinks you have a 40 track drive with 
an 80 track disk in it or some such tomfoolery.


-- 
Cheers, Gene
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)

Some people have parts that are so private they themselves have no
knowledge of them.