[Coco] RGB/HDB-DOS question

[Robert Gault]

Robert Emery wrote:
> This is mainly for Boisy and/or Robert Gault...
> 
> There are programs for RSDOS that patch basic for 40 or 80 track access. Is it
> safe to do this under HDB-DOS? or is it likely to corrupt the hard drive?
> 
> What if the 40 track patch was used before formatting the drives? Assuming it
> worked, that would change the OS-9 offset, right?
> 
> I have just finished formatting my first CoCo HD under HDB-DOS. Yay. I have the
> latest release of NitrOS-9 booting, now where can get IDE driver/descriptor for
> NOS-9? (if possible, already assembled, I'm aware of the CVS source)
> 
> Thanks,
> Bob Emery
>

The short answer is no there are no patches for 40/80 track drives. The 
long answer follows.

I can't speak for Boisy and I don't know what the latest HDB-DOS is 
doing. That being said, HDB-DOS was based on the Ken-Ton RGBDOS and 
probably still follows the 35 track "drive" model. You can't use patches 
designed for Disk Basic on RGBDOS or HDB-DOS because at the very least 
the patches could conflict with the patches that RGB/HDB-DOS installed.

Just for the sake of argument, it is possible to rewrite these DOS so 
that 40 or 80 track disks could be used. It would require the source 
code as well as the source code of the patches that use 40/80 track 
disks. It would also require some of the tricks of Extended ADOS-3 that 
Art used to increase the size of the Disk ROM because there is no room 
left in the current DOS for extensive changes. Art is going to post 
ADOS-3 on the Internet and if you are very lucky, the source code might 
be available. The accessibility of the HDB-DOS source code is up to 
Boisy but I doubt he would release it.

Any patching done to make the HDB-DOS "drives" 40 tracks would have no 
effect on the offset to the start of the drive 0. Low level formatting 
of an HDB-DOS hard drive has no impact on what the ROM will see or do 
with the drive. If you did patch the ROM for forty track use, then the 
ROM would not work with your existing drive if you have already done 
high level formatting with DSKINI for the Disk Basic portion.