Jan Gutter wrote:
Greetings!
I have just read the thread about your problems with the USB card reader
you had in February and March. I'm particularly interested, because I
have the exact same device in my computer (at least, the USB ID's match)
(floppy drive + card reader combination). I intended to use it for
accessing my SD cards, but I've had no luck in Linux. I've always used
my external card reader (another model) to work in Linux, but when I
boot into Windows, the internal card reader also works.
In your thread you said that TEAC had come up with an answer? Was it a
hardware swap-out? If not, I'd be supremely interested!
Thanks for your time,
Yours sincerely,
Jan Gutter
+------------------------------+
|name: Jan Gutter |
|company: LucidView |
|email: [EMAIL PROTECTED] |
|mobile: +27824422233 |
|personal: [EMAIL PROTECTED] |
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Chuck Norris plays racquetball with a waffle iron and a bowling ball.
Hi Jan,
actually TEAC changed the card reader hardware completely. Previousely they
used a chipset called "Carry Logic, Winter 1.3". Now they use "Genesys Logic
GL819". It is interesting that there is a very similar Floppy/Cardreader
combination from Mitsumi. And now - suprise - Mitsumi has changed its intenal
electronics the same way! Actually the card reader electronics of the TEAC and
MITSUMI model are identical. There is even a "Mitsumi" label on the TEAC board :-)
You can identify the verion you have by looking into CF card slot. When there
is a dark blue PCB, its the old board. But if the PCB color is green, its the
new, working electronics.
To me it looks like the first generation of USB2.0 card reader chips did not
perform very well when used for writen (hence the name card READER).
There was some kind of software workaround implemented into the Windows
drivers. But even there, after hard testing, errors occured.
Now the new chip generation solved this kind of write issues und works as
expected. Therefore Linux drivers have no problems any longer.
The new electronics have another effect, too. We found the internal USB
cabling of our chassis was very, very poor. There is a dual USB cable from
motherboard to front I/O. We use one of theses USB channels for card reader,
the other goes to an internal HUB. With the old electronics our HUB worked
just fine, only card reader had errors. With new electronics and original USB
cabling our HUB refused to work. We examined the original USB cable and found
it was just an 8 wire signal cable without any twistet pairs or shielding! It
is amazing that some USB2.0 deviced worked at all when using this cable.
Now we changed to two seperate single channel cables and everything is ok.
So old TEAC electronics put some kind of "weak" signals onto USB cable and
crosstalk between channels was low enough to not disturb our HUB.
New TEAC electronics uses "stronger" signals and we get a lot of crosstalk, so
we had to use separate cables. By the way: such a thing as a "dual-channel
cable" is nowhere mentioned in USB2.0 spec. Nevertheless a lot of chassis
manufacturers use just that kind if cable.
Please get me right, old TEAC problems did not come from bad cabling. We used
several high quality cables for testing and old TEAC did not work, either.
So to make a long story short: TEAC did a hardware swap out. We had to replace
all old card readers in the field by the new ones. Unfortunately TEAC did not
change product revision or ID. So there is no other means than looking at the
PCB (blue=old, green=new) to distinguish models without powering them.
Thomas
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