[Coco] HDB-DOS Eprom

[Gene Heskett]

On Friday 18 March 2016 18:18:59 Tormod Volden wrote:

> On Fri, Mar 18, 2016 at 9:59 PM, Gene Heskett wrote:
> > On Friday 18 March 2016 15:59:17 Tormod Volden wrote:
> >> Out of curiosity, what is the origin of the $5A000 value?
> >
> > That is sector offset to the beginning of the HDBDOS/basic disks,
> > and allows 94,371,840 megabytes for os9, which is about 3/4 of what
> > can be handled with a cluster size of 1.  Above about 132 megs it
> > needs a cluster size of 2, then 4 at just above 250 megs, moving up
> > in powers of 2, so my 1Gb seagate I have as S1, is running with a
> > cluster size of 16, or $10 in hexidecimal.  We run out of cluster
> > size room at about 4Gb IIRC.
>
> I know the maximal /sector/ number is 0xFFFFFF, so I can understand
> different /sector/ sizes give different maximal capacities. But why
> does the cluster size play a role? Is there a limit to the cluster
> allocation bit map size?
>
> Tormod

Yes, 64k max.


Cheers, Gene Heskett
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