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

[Gene Heskett]

On Friday 23 September 2005 22:49, Dave Kelly wrote:
>Diego Barizo wrote:
>>   I've been reading the OS-9 manual, and I understand that the FAT
>> uses 3 bytes - 24 bits - to keep track of the files sectors.
>> That would give 16777216 sectors, and at 256 bytes a sector,
4194304
>> Kb, or 4 Gb
>> Is that the maximum size of HD partition that OS-9 can work with?
>> What is the biggest HD any of you has ever used with OS-9?
>>
>> Also, the manual says something about the files being able to be as
>> big as the media. Did I get it right? Could OS-9 in 1985/6 work
>> (theoretically) with files over 2 GB, something that Windoze
machines
>> could not do until the release of WinXP some 23 years latter?
>>
>> Diego
>
>Your math is correct. But look at your allocation table. 1 sector =
256
>byte x 8 bits = 2048 sectors of storage x 256 (sector size) = 624,280
>hard disk size possible.

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.

>Unless:
>
>When I stuck my 2 gigger in my OSK machine and let it figure its own
>format.  Came up with a sector size of 4096 bites each.

That should have been the optimum, correct cluster value for a 2
gigger.

-- 
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