[Coco] [Color Computer] Hard Drive sizes
Boisy G. Pitre
boisy at boisypitre.com
Thu May 13 11:38:45 EDT 2004
On May 13, 2004, at 9:31 AM, Allen Huffman wrote:
> Q: how large of a HD can OS-9 L2 address w/o clustering?
> I can't remember! Too long. I want to buy the IDE/compact flash
> interface this weekend at CoCoFest, and need to pick up some CF parts
> beforehand. Ideally large enough for 256 RGB-Dos drives and OS-9.
Gene's previous post seems correct: (65535 * 8) = 524,280 256-byte
sectors is the max that can be represented at 1 sector per cluster with
the current RBF.
Of course, on CF devices, sector sizes are 512 bytes, so (524280 / 2) =
262,140. Any 512-byte sector device whose capacity exceeds 262,140
sectors will need to be formated with a cluster size of 2 or greater.
I've found that a 128MB CF is a good size for the CoCo. For the max of
256 HDB-DOS drives, you will need to reserve (630*256) = 161,280
sectors, or (161,280 * 512) = 82,575,360 bytes on a 512-byte sector
device. That leaves 20+MB for NitrOS-9, which is plenty by far.
FYI, I believe Mark will be selling CompactFlash along with the
SuperIDE as a package deal at the fest this weekend.
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