[Coco] Biggest OS-9/Nitros-9 HD?

[Dave Kelly]

Gene Heskett wrote:

>>byte x 8 bits = 2048 sectors of storage x 256 (sector size) = 624,280
>>hard disk size possible.

I'll accept your 524,288 if you accept that at the time I multiplied 
that this morning I had a hurricane in the neighborhood.
> 
> 
> You are calulating how many clusters the disk can contain I take it. 
> But kcalc gives me 524,288 clusters for 65536 (maximum FAT size) x 8
> (bits per byte). That translates to a maximum disk size if a cluster
> is 1, of 134,217,728 bytes.  Changing the cluster size by powers of 2
> is one option and the code is in rbf.mn to handle this.


This is what I remember, although I have had a couple of dreams since I 
first conceived this understanding :)

The storage area on the disk that tells if a sector is in use is of size 
  sector, 256 bytes. Each bit in that sector that is set denotes that a 
sector is in use, if the 3rd bit of the sector is set, the 3rd sector is 
in use, and not to be overwriten.

If the above is correct then 256 x 8 = 2048 places are alloted to mark a 
cluster in use.  Each cluster is one sector in size or 256 bites. My 
understanding is that 48 - 5 bite date units at the end of the file 
descripter were there only to allow the file to be spread over the 
entire disk if needed, or where ever there was an empty sector available.