SD cards and lost space - how to reduce?

Archived from groups: microsoft.public.pocketpc (More info?)

I have just got a 512mb SD card and note that is shows the free space as
480.

I know that cards have some kind of "hidden" away sector so they can work,
but 32MB seems a bit large to me!! Is there anyway to reduce the size of
that "section"? More songs for the plane on holiday soon that way!!;-)

if it helps, I have Pocket Mechanic, if there is an option on the that will
help?

Cheers guys!

Archived from groups: microsoft.public.pocketpc (More info?)

You have a standard format, to reduce the area for the filing system would
mean using a non-standard system which may cause issues in other areas.
There is a directory listing, and a backup copy in case of problems. This
points to a File Allocation Table (FAT) which keeps track of all of the
sectors used to store each file. Remember that even the data sectors need
something to identify them, and say when they are finished, it's all just
part of the format structure- without structure you may not be able to
find/use the data.
One 'problem' with memory cards is the way they generally use 1000's rather
than 1024's for disk space calculations- meaning the perceived/actual space
is reduced compared to the way it is calculated for RAM in computers. This
way is also used for hard disks.
If you want to custom format the disk FAT32 uses smaller data sectors than
FAT16, so the average wasted space per file will be reduced. There are
utilities to custom format disks for special purposes (eg reduced directory
entries), but I don't know if the ppc os will read them. If there are errors
they may be more difficult to correct when you custom format a disk/memory.
It's probably not worth the bother- if you want more space you are better
off buying a bigger card.



"Neal Smith" <nealsmith@tiscali.co.uk> wrote in message
news:40b3a68f_1@mk-nntp-2.news.uk.tiscali.com...
> I have just got a 512mb SD card and note that is shows the free space as
> 480.
>
> I know that cards have some kind of "hidden" away sector so they can work,
> but 32MB seems a bit large to me!! Is there anyway to reduce the size of
> that "section"? More songs for the plane on holiday soon that way!!;-)
>
> if it helps, I have Pocket Mechanic, if there is an option on the that
will
> help?
>
> Cheers guys!
>
>

Archived from groups: microsoft.public.pocketpc (More info?)

"Graham in Melton" <nota@nospamplease.net> wrote in message
news:BCD97B0A.277C8%nota@nospamplease.net...
> On 25/5/04 9:02 pm, in article 40b3a68f_1@mk-nntp-2.news.uk.tiscali.com,
> "Neal Smith" <nealsmith@tiscali.co.uk> wrote:
>
> > I have just got a 512mb SD card and note that is shows the free space as
> > 480.
> >
> > I know that cards have some kind of "hidden" away sector so they can
work,
> > but 32MB seems a bit large to me!! Is there anyway to reduce the size of
> > that "section"? More songs for the plane on holiday soon that way!!;-)
> >
> > if it helps, I have Pocket Mechanic, if there is an option on the that
will
> > help?
> >
> You've fallen for the eternal argument
>
> What is a megabyte and what is a kilobyte ?
>
> Take 512000divide byt 10124 and divide by 1024 and you get 488 - which
looks
> like what you have
>
> Yes, you've been misled, as have most people when buying memory cards
>

Eternal argument?
The ships travelling to America to colonise the area had this as a matter of
discussion to help fill the journey time? Was this discussed by Homer? The
cavemen argued about it? I think you are exaggerating more than a little.

The problem is the guys using this smaller capacity on the card solution use
the ISO/ANSI definitions for kilo, mega where these are 1,000 and 1,000,000
etc. so may be considered correct.
For example:
-a kilometre run is 1000 m not 1024 m.
-a kilogram of sugar is 1000 g not 1024 g


The traditional method (for computer memory) uses the more logical powers of
2 for this kind of usage.
2 ^ 10 = 1024,
2 ^ 19 = 524,288,
2 ^ 20 = 1,048,576

I'm not sure misled is right, possibly lack of understood. And it is
compounded by industry using one term with two distinct and different
meanings. Perhaps it is time to clear up this difference by using a
different term for the computer binary based kilo, mega etc.?

Archived from groups: microsoft.public.pocketpc (More info?)

"Meindert Sprang" <mhsprang@NOcustomSPAMware.nl> wrote in message
news:10b8qts7993es06@corp.supernews.com...
> > > On 25/5/04 9:02 pm, in article
40b3a68f_1@mk-nntp-2.news.uk.tiscali.com,
> > > "Neal Smith" <nealsmith@tiscali.co.uk> wrote:
> > >
> > > > I have just got a 512mb SD card and note that is shows the free
space
> as
> > > > 480.
> > > >
> > > > I know that cards have some kind of "hidden" away sector so they can
> > work,
> > > > but 32MB seems a bit large to me!! Is there anyway to reduce the
size
> of
> > > > that "section"? More songs for the plane on holiday soon that
way!!;-)
>
> SD cards use flash memory. And this kind of memory always has a size that
it
> a power of two. So a 512Mb card has 512 x 1024 x 1024 bytes. But, these
> types of memory is divided into hardware sectors of 16 to 64 kbyte. On top
> of that goes a filesystem that works with sector sizes of 512 to 4096
bytes.
> However, the flash chips can only be erased by a hardware sector, which is
> much larger that a logical sector. Therefore, space is reserved for this
> kind of operation. Also, the entire bookkeeping of logical sectors and
files
> takes up that much space.
>
> Meindert
>
>

No. Look at the manufacturers sites. It is 2 to a power, not a power of 2.