FAT16 vs FAT32

[Gary Owen]

Please excuse me if this has already been covered but after searching
the archives, I was unable to find answers to these questions.

It seems ROM 2.00 formats the SD card now to FAT32.

Is there any advantage to keep using FAT16 or would it be better to
change everything over to FAT32? I have 128MB SD cards.

Regarding longer filenames with FAT32, it appears the 49g+ still
truncates the names when stored on a FAT32 SD card. How come?

Thanks in advance.
Gary

[ObyWanKenoby]

>Is there any advantage to keep using FAT16 or would it be better to
>change everything over to FAT32? I have 128MB SD cards.

You can format bigger SD-CARD and take more dir on SD.

>Regarding longer filenames with FAT32, it appears the 49g+ still
>truncates the names when stored on a FAT32 SD card. How come?

Because the HP is NOT LNF compliant on SD in order now.

[Erwann ABALEA]

Bonsoir,

On Sun, 15 May 2005, Gary Owen wrote:

> It seems ROM 2.00 formats the SD card now to FAT32.
>
> Is there any advantage to keep using FAT16 or would it be better to
> change everything over to FAT32? I have 128MB SD cards.

I see only one advantage to stay with FAT16, if you have another device
that might read the same card, and doesn't know about FAT32.

Switching to FAT32 will allow you to lose less space (statistically,
you'll waste 0.5*cluster size*nb of files), and you'll have no limit on
the number of files on the root (in fact, no other limit than the size of
the card). Long file names have been available before Microsoft introduced
FAT32.

--
Erwann ABALEA <erw...@abalea.com> - RSA PGP Key ID: 0x2D0EABD5
-----
>COIN !
Comment ça coin ?
Juste melangé 8.5 et X je suppose...
-+- In : Guide du Neueu Usenet - Le canard se déchaine -+-

[horsz...@gmail.com]

Forgive me for sounding redundat, When I formatted my SD card there
was no choice to format FAT16 or FAT32 and the card was formatted FAT16
no questions asked.
So where is the option to format FAT32?

Thanks

Luis

[Jean-Yves Avenard]

horsz...@gmail.com wrote:
> So where is the option to format FAT32?

if card <= 32MB -> FAT16
if card > 32MB -> FAT32

JYA

[f4ding]

This might be slightly off-topic, but I tried using a 2gb SD card, and even
when the card is empty, the filer only shows 900,000+kb of space, which is
about 1gb of space.

I reformatted the card using a PC and still no luck. I wonder what is
going on.

[VPN]

"f4ding" <aris...@NOSPAMyahoo.com> wrote in message
news:2e32bc3b303917de...@localhost.talkaboutcomputing.com...

and did you then again try to reformat it using the calc?
Please try , try again and report here

I'm planning to get Sundisk USB/SD-card
VPN

[Minkey]

And what was the ROM V1.23 logic? FAT12 for small, FAT16 for big SD
cards??

[VPN]

"Minkey" <cmi...@telus.net> wrote in message
news:1117215109.9...@g49g2000cwa.googlegroups.com...

> And what was the ROM V1.23 logic? FAT12 for small, FAT16 for big SD
> cards??

I'm not sure, looked more like FAT16 for all, but supports FAT12, too
VPN

[Minkey]

Looking at the ROM binary files, it seems both ROM 1.23 and ROM 2.0
still have the hooks for formatting to FAT12 or FAT 16.
Perhaps some obliging programmer disabled them?

>From ROM 2.0:
01EBC0 ÿÿ.1.start form
01EBD0 atting..press en
01EBE0 ter to cancel...
01EBF0 q .mb.. v .form
01EC00 at to fat16.form
01EC10 at to fat12.FORM
01EC20 ATTING..........

01EFB0 | . size:...form
01EFC0 at to fat32.ÿ .

>From ROM 1.23:
01C520 enter start form
01C530 at..others cance
01C540 l format....size
01C550 :...mb..à@ .form
01C560 at to fat16.form
01C570 at to fat12. ðÿÿ

[f4ding]

Everytime I try to format with the filer or a menu through ON+F4, I get a
format failed message. Although trying to format through ON+F4 menu at
least it was recognized that the SD is 1938MB in size.

[James M. Prange]

If the card is 8MB, then the 49g+ (with ROM 2.00) formats it to
FAT12. That requires more than one sector per cluster for this
card size, which I think is undesirable for the calculator, but
the bigger problem is that the calculator doesn't seem to work
correctly with FAT12. It does recognize that the card is there,
but the filer shows 0KB for its size, and trying to store anything
on it results in an error. MS Windows 98SE also formats this size
to FAT12.

This seems rather a shame, as an 8MB card should be plenty big for
ordinary calculator uses, and smaller (particularly 64MB or less)
cards are available at low prices on eBay (but be careful of
"shipping" and required insurance costs).

Using a disk editor, I tweaked the boot record to 1 sector per
cluster, 1 reserved sector, 61 sectors per FAT (my "8MB" MMC seems
to have 15680 sectors available), and FAT16. Naturally, this
results in the FATs and root directory being at the wrong sectors;
I could've edited them myself, but I just let MS ScanDisk make
those repairs. Now I have it formatted to FAT16 with 1 sector
reserved for the boot record, 122 sectors for the two FATs, 32
sectors for the root directory, and 15525 clusters at one 512-byte
sector per cluster (7948800 bytes, 7762.5KB, or a little over
7.58MB), so everything adds up. At 61 sectors each, the FATs are
sufficient for up to 15614 clusters. For whatever reasons, the
filer shows me "7761KB", but I'm not going to lose any sleep over
that.

A 16MB SD card formats to FAT16 with 1 sector per cluster; good.

I don't have a 32MB card to try just yet.

A 64MB MMC formats to FAT32 with 1 sector per cluster; good again.

A 128MB SD card formats to FAT32, but with 2 sectors per cluster.
I'll have to do some studying to be sure of how to safely change
that to 1 sector per cluster. On the other hand, I'm not at all
likely to store enough files on it to use up all 122034 clusters
anyway.

But with the cards formatted to FAT32, there seems to be a very
disconcerting delay when the calculator is turned on. Maybe I'll
format the cards back to FAT16, and just live with 2-sector
clusters on the 64MB and 4-sector clusters on the 128MB.

But now that I've thought about it, Norton Disk Doctor seems to
have a problem with any card formatted on the calculator,
regardless of it size. It sometime warns of an "Invalid Disk Table
in Boot Record" (presumably because of the number of sectors per
track and number of heads stored there), and doesn't seem to be
able to repair this "error" correctly. This warning could be
safely ignored, but I chose to tweak the boot record so that its
disk geometry matches the simulated disk geometry. Now neither MS
ScanDisk nor Norton Disk Doctor reports any error.

Strangely, although the calculator formats the larger cards to
FAT32, a FAT32 formatted card doesn't seem to work for updating
the ROM. The update routine shows me:

NO SCRIPT FILE
CHECK CARD
THEN PRESS ANY KEY

even though the two required files are clearly present. A "paper
clip reset" is required to break out of this. I guess that the
update routine is expecting a FAT16 card. This is with boot
version 3.19. Yes, I do realize that changing the update routine
to work with different file systems may well be more difficult
than changing the way that the OS formats cards and which file
systems it can use.

Maybe a ROM revision 2.01 can be expected? Although it seems that
for updating from an MMC or SD card, the user will first have to
make sure that the card is formatted as FAT16.

--
Regards,
James

[VPN]

"James M. Prange" <jmpr...@i-is.com> wrote in message
news:cb238$429c0e40$4267ebd3$58...@123.NET...
X

> Maybe a ROM revision 2.01 can be expected? Although it seems that
> for updating from an MMC or SD card, the user will first have to
> make sure that the card is formatted as FAT16.

X
All the SD card problems including reflashing the ROM
from FAT12, FAT16, FAT32
and the delays should be fixed
PLUS
the annoying keybounce, too!
Bring back ->KEYTIME & KEYTIME->
VPN