[Coco] Multiple HDB-DOS 256 drive partitions Software Wanted

[Gene Heskett]

On Wednesday 24 April 2013 21:02:23 Aaron Wolfe did opine:

> On Wed, Apr 24, 2013 at 12:37 PM, Boisy Pitre <boisy at tee-boy.com> wrote:
> > There hasn't been a partitioning table feature done as far as I know
> > on the CoCo.
> > 
> > Actually, there is enough unreserved space in RBF's LSN0 to allow for
> > some limited partitioning, but no one has attempted to commandeer
> > that area for anything.
> 
> When I was doing the RBF filesystem stuff in DW, I noticed that you
> can find everything you need to know to verify an RBF filesystem
> exists in LSN0, including exactly where the filesystem should stop on
> the underlying disk.
> 
> Wouldn't it be a fairly simply hack to make descriptors like /i0 /i1
> /i2 /iX etc where upon initialization each one greater than 0 "skips"
> X number of RBF filesystems, looking for another valid one starting on
> the sector immediately after the end of the previous, until it finds X
> valid RBF LSN0's and records its own offset all automagically?  It's
> pretty easy to verify a valid RBF filesystem with very little doubt
> you've found one.
> Essentially you don't need a partition table if the RBF partitions are
> arranged sequentially on the disk.
> 
> $0.02
> -Aaron

I suspect you are right Aaron, but the search logic should be trained to 
skip ahead 16,128 additional sectors if it doesn't find an os9 filesystem 
lsn0 at the usual next sector offset.  That way it would skip the HDBDOS 
vdisk area some of us have setup before it wasted time trying to find the 
next partitionable region.  If it just started marching thru the HDBDOS 
area, it would latch up on the first floppy image that was in fact an os9 
bootable vdisk, and that would obviously be a mistake.

Is there a marker for an rsdos image in LSN0 of such an image?  That would 
also assume its been formatted by one or the other systems too because I 
have looked at unused vdisks with dEd and found old amigados data because 
that is where those 2 drives once served.

It is however, an intriguing thought as properly done at boot time, it 
could find stuff that you have forgotten it was even there.

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Cheers, Gene
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