Card Reader

I just bought a Dynex CF card reader (Model: VPN: DY-CF131). It came with
no instructions whatsoever. Seems to work fine, although the cards are a
little difficult to engage on the tracks; once positioned however, they
seem to slide home satisfactorily.

My question concerns when to load the media. Does one first connect the
reader to the USB port and THEN load the card? Or can the card be loaded
before the reader is plugged into the computer? And what is the correct
order for taking the card out?

Thanks.

Roger

Roger wrote:
I just bought a Dynex CF card reader (Model: VPN: DY-CF131). It came with
no instructions whatsoever. Seems to work fine, although the cards are a
little difficult to engage on the tracks; once positioned however, they
seem to slide home satisfactorily.

My question concerns when to load the media. Does one first connect the
reader to the USB port and THEN load the card? Or can the card be loaded
before the reader is plugged into the computer? And what is the correct
order for taking the card out?

Thanks.

Roger



My own experience with different cards, readers, and PCs, I've never had
a situation that made me think it matters.

--
jer
email reply - I am not a 'ten'

In article 34,
Roger wrote:

I just bought a Dynex CF card reader (Model: VPN: DY-CF131). It came with
no instructions whatsoever. Seems to work fine, although the cards are a
little difficult to engage on the tracks; once positioned however, they
seem to slide home satisfactorily.

My question concerns when to load the media. Does one first connect the
reader to the USB port and THEN load the card? Or can the card be loaded
before the reader is plugged into the computer? And what is the correct
order for taking the card out?

Do whatever works. At least on Mac OS X, if I plug in a card reader with
a CF card already in the reader, my Mac won't see it. I have no clue if
Windows behaves the same way or if this behavior varies from one card
reader to the next. If both methods work, then pick whichever one works
best for your work habits.

It makes absolutely no diference. All methods usually work.
Jack

My question concerns when to load the media. Does one first connect
the reader to the USB port and THEN load the card? Or can the card be
loaded before the reader is plugged into the computer? And what is the
correct order for taking the card out?

Roger wrote:
I just bought a Dynex CF card reader (Model: VPN: DY-CF131). It came with
no instructions whatsoever. Seems to work fine, although the cards are a
little difficult to engage on the tracks; once positioned however, they
seem to slide home satisfactorily.

My question concerns when to load the media. Does one first connect the
reader to the USB port and THEN load the card? Or can the card be loaded
before the reader is plugged into the computer? And what is the correct
order for taking the card out?

On Windows it probably doesn't matter what you do. Microsoft had about
a billion dollars to spend on testing all the possible things people
could do with a USB card reader, and I'll bet they so something
reasonable for each case. Windows doesn't graft the card into the
filesystem the way Unix does, so there's no consequence to just
pulling the card out or unplugging the cable.

On Linux, I always unmount the card's filesystem before disconnecting
it from the computer. I haven't looked at the code to see what happens
on the mount of a fat32 filesystem, but native Unix filesystems do a
little interlocking-inodes dance during a mount, and the filesystem can
only be unmounted if the media is present so the dance can be reversed.

I imagine MacOS X is similar to Linux, but don't really know.

Paul Allen

On Fri, 11 Nov 2005 22:25:20 -0800, Paul Allen "paul dot l dot allen at
comcast dot net" wrote:

On Windows it probably doesn't matter what you do. Microsoft had about
a billion dollars to spend on testing all the possible things people
could do with a USB card reader, and I'll bet they so something
reasonable for each case. Windows doesn't graft the card into the
filesystem the way Unix does, so there's no consequence to just
pulling the card out or unplugging the cable.

splutter, choke Good heavens - are there *still* people around who are
naive enough to think that because Microsoft has lots of money it will
therefore produce good quality software?

(Having said that, I haven't had any problems with USB so far. Maybe
they did get that right.)

--
Stephen Poley

Roger wrote:
I just bought a Dynex CF card reader (Model: VPN: DY-CF131). It came with
no instructions whatsoever. Seems to work fine, although the cards are a
little difficult to engage on the tracks; once positioned however, they
seem to slide home satisfactorily.

My question concerns when to load the media. Does one first connect the
reader to the USB port and THEN load the card? Or can the card be loaded
before the reader is plugged into the computer? And what is the correct
order for taking the card out?

Thanks.

Roger

Plug in the reader, wait until the software driver loads, then plug in
the card. When unplugging, make SURE that all read and write operations
are complete, then just pull out the card. Unplugging the reader
depends of the OS you are using.
Generally, if there is an icon representing the reader, you can select
it and dismount the reader according to the OS instructions, then unplug
the reader.


--
Ron Hunter

Paul Allen wrote:
Roger wrote:
I just bought a Dynex CF card reader (Model: VPN: DY-CF131). It came
with no instructions whatsoever. Seems to work fine, although the
cards are a little difficult to engage on the tracks; once positioned
however, they seem to slide home satisfactorily.

My question concerns when to load the media. Does one first connect
the reader to the USB port and THEN load the card? Or can the card be
loaded before the reader is plugged into the computer? And what is the
correct order for taking the card out?

On Windows it probably doesn't matter what you do. Microsoft had about
a billion dollars to spend on testing all the possible things people
could do with a USB card reader, and I'll bet they so something
reasonable for each case. Windows doesn't graft the card into the
filesystem the way Unix does, so there's no consequence to just
pulling the card out or unplugging the cable.

On Linux, I always unmount the card's filesystem before disconnecting
it from the computer. I haven't looked at the code to see what happens
on the mount of a fat32 filesystem, but native Unix filesystems do a
little interlocking-inodes dance during a mount, and the filesystem can
only be unmounted if the media is present so the dance can be reversed.

I imagine MacOS X is similar to Linux, but don't really know.

Paul Allen
Win2K and WinXP will scold you if you just pull the cable, but unless
writing has not completed, no harm is done. Pulling the card, as in
switching to another card, requires only waiting on all activity to
stop, and pulling the card.


--
Ron Hunter

Stephen Poley wrote:
On Fri, 11 Nov 2005 22:25:20 -0800, Paul Allen "paul dot l dot allen at
comcast dot net" wrote:

On Windows it probably doesn't matter what you do. Microsoft had about
a billion dollars to spend on testing all the possible things people
could do with a USB card reader, and I'll bet they so something
reasonable for each case. Windows doesn't graft the card into the
filesystem the way Unix does, so there's no consequence to just
pulling the card out or unplugging the cable.

splutter, choke Good heavens - are there *still* people around who are
naive enough to think that because Microsoft has lots of money it will
therefore produce good quality software?

(Having said that, I haven't had any problems with USB so far. Maybe
they did get that right.)

My only problem with card readers was with the internal one in my wife's
computer. I tried to dismount the reader, and found that using it again
required a reboot. The proper action is to just pull the card after all
activity is complete.


--
Ron Hunter

Paul Allen "paul dot l dot allen at comcast dot net" wrote:

On Linux, I always unmount the card's filesystem before disconnecting

Unnecessary, but it won't hurt anything of course.

it from the computer. I haven't looked at the code to see what happens
on the mount of a fat32 filesystem, but native Unix filesystems do a
little interlocking-inodes dance during a mount, and the filesystem can
only be unmounted if the media is present so the dance can be reversed.

The media only needs to be present if it has been written to,
and the buffers are dirty.

Usually if it has been more than perhaps 15 seconds or so since
any write activity has been seen on the hardware, pulling the
card out won't harm anything at all. I do it all the time...

As for mounting it originally, that does get wierd. With a USB
card reader you don't want the card in place when the system is
booted, for example on a laptop. I'm not sure about the reader
(it may not matter, I haven't tried). Plugging in the
reader/card causes the necessary modules to be loaded, and that
won't happen if the card is already in when it goes through the
initialization process at boot time.

And the card can be a different drive on different systems too,
and may be different each time on any given system depending on
what else has been or not been loaded.

Here's a shell function that I use on one system to mount a CF
card on /mnt. This is from my ~/.bashrc file.

alias u='umount /mnt'

function m1 {
umount /mnt 2/dev/null
for i in sda1 sdb1 sdc1 sdd1 ; do
if mount -t msdos /dev/$i /mnt 2/dev/null ; then
echo "Mounted $i on /mnt"
return 0
fi
done

echo "Can't mount the filesystem..."
return 1
}

Note that I mount systems on /mnt, not on subdirectories in
/mnt, which has advantages but may not be what some users are
used to seeing. (One advantage being that universally useful
'u' alias...)

--
Floyd L. Davidson http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)