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

[Bill Gunshannon]

> On Wednesday 24 April 2013 10:53:55 Mark Marlette did opine:
>
>> Luis,
>>
>> I don't believe this is correct.
>>
>> In the current configuration of  the NitrOS-9 offset is 0 and works as
>> you say but.....
>>
>> If you were to add an offset to the SuperDriver descriptor it would then
>> use that as it's relative LSN0 offset.
>>
>> The size / drive geometry then kicks in to effect and you go up from
>> there.
>>
> There is a bit, IIRC in the IT.TYP byte of the descriptor, and I miss
> typed
> in the previous nsg & called it IT.DNS, my bad!
>
> See the superdriver descriptor doc you have on your site, which tells
> format whether it should query the drive for its geometry and size, or
> should take the descriptor info as gospel.  For a virtual floppy, my /sh's
> IT.TYP is $81, but READ the docs!
>
> THIS BIT IS THE MOST DANGEROUS MINEFIELD IN NITROS9.
>
> Read, and set the bits in each device descriptor very carefully else you
> may format the whole drive with a MB script.
>
> YOU HAVE BEEN WARNED!
>
> With this bit properly set, and the offsets in the descriptor properly set
> so its safe to format based on the descriptor, you can do anything you
> want. One could theoretically setup the first partition at 120 megabytes
> so
> it would only need a 1 sector per cluster FAT map, then setup the next
> 41,287,680 bytes of the disk as 256 hdbdos virtual floppies, then do the
> next 120 megs as a 2nd os9 partition, then by poking new values into
> HDBDOS, have another 41,287,680 byte piece of the drive as vdisks 257-512,
> and repeat that several more times on a 1Gib disk.  All accessable at the
> same time with nitros9 if you have enough /sh-like descriptors in the
> bootfile, each properly configured, with even the 257-xxx hdbdos vdrives
> being bootable with the use of my bootlink utility.
>

Wow...  This reminds me so much of Ultrix-11.  Absoluteley nothing
actually on the disk to tell you what the partitioning is.  If you
chose to do non-standard partitions and then moved the disk to a
different system, pfftttt.  All gone.  Take the warnng above very
seriously,  :-)

bill

-- 
Bill Gunshannon          |  de-moc-ra-cy (di mok' ra see) n.  Three wolves
billg999 at cs.scranton.edu |  and a sheep voting on what's for dinner.
University of Scranton   |
Scranton, Pennsylvania   |         #include <std.disclaimer.h>