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Re: 32MB is size???
- Subject: Re: 32MB is size???
- From: "mspangler" <mspangler@gemsi.com>
- Date: 1 Apr 2006 16:24:07 -0800
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Jack Tseng wrote:
> Apple DOS provides the 16 sector low-level format of DOS 3.3 for 5.25 inch
> disks. DOS 3.3 can store up to 16MB in size. New ProDOS introduced a new
> high level format that stores up to 32MB in size. Does it mean 512 bytes per
> sector or double "65535" ? If not that, how does it make 32MB in size?
>
> Thanks!
> Jack
Prodos uses a 512 byte block, which is 2 of the 256 byte floppy disk
sectors. Most hard drives use a 512 byte sector, which made things
easy.
So, 2^16 is 65536 times 512 is 33,554,432 bytes, which we call 32
megabytes for short.
Note that the maximum file size is 16 megabytes for truly obscure
reasons involving the number of directory blocks available. See the
book "Beneath Apple prodos" for details.
Mike S.