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

[Brett Gordon]

Oh, bummer!   I was hoping for a PC style partition table, or any style
partition table that would support more than two operating systems.  I was
also hoping too hard that this data would be stored on the disk itself
rather than in ROM ( like a volume carrying its own metadata ).   Sorry, it
seems my "what if" and "geeze whiz... that would be cool"  must have
mis-translated this thread!   :)


On Thu, Apr 25, 2013 at 5:09 PM, Robert Gault <robert.gault at att.net> wrote:

>
>
> The partitions referred to in this thread should not be confused with PC
> hard drive partitions. HDBDOS and RGBDOS split a hard drive into two
> sections based on three bytes in the Disk ROM. These bytes, $D938-$D93A,
> give the address of the first Disk Basic sector on the hard drive. There is
> no indication on the drive itself that sectors differ on either side of
> this "border".
>
> The sectors can be any size in bytes and that is a function of the hard
> drive, hardware or emulation. Regardless of the sector sizes, Disk Basic
> can only use 256 bytes per sector. The rest will be wasted unless unless
> the ROM is modified to work with pseudo sectors. OS-9 can do this but there
> is not enough room in the Disk ROM to compensate for alternate size
> sectors. Only the first 256 bytes will be used.
>
> All emulators use 256-byte sectors.
>
>
>
> --
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/**mailman/listinfo/coco<http://five.pairlist.net/mailman/listinfo/coco>
>



-- 
Brett M. Gordon,
beretta42 at gmail.com