Status of the Tascam US-122mkII???

Status of the Tascam US-122mkII???

[jordan johnston]

hello,

Recently, i have gotten my hands on a Tascam US-122mkII.  i have done
a lot of reading/googling and i can see that the device has been added
to the snd-usb-us122l  and even-cross referenced my own device to make
sure the Id and such were there.
Currently, i am unable to get sound out of the Unit.   it does
however, power up on boot.
I have tried many things to get it working, and i have even gotten
Jack to give me the option of picking this Device, however it shows
errors
and does not work :(

**** I am curious about the status of these drivers??

**** does anyone have this unit working at all?

**** and the steps they used to get it working. ( as much of the info
i have read doesn't seem quite uptodate )

is there possibly firmware for this unit or do i use the -US122L
firmware instead?

for Just a bit of background, I am using Fedora 12 with Planet CCRMA.
however, i do not using the CCRMA kernel, as it doesn't cut it for me.
A: it doesn't support a lot of newer hardware, B: it doesn't use MSI-X
on my machine(shared USB/soundcard) C: It's  bloated... D: no BFS
scheduler.
Instead i am using Zen-kernel  which tends to be a lot more up to
date, and i have gotten much better performance from Zen than any
other
kernel on any distro i have ever used.

now, I am more than willing to provide any information that might
help....  this is what i know so far.

dmesg:

ALSA sound/usb/usx2y/usb_stream.c:603: status=-2
ALSA sound/usb/usx2y/usb_stream.c:603: status=-2
ALSA sound/usb/usx2y/us122l.c:365: us122l_start error -14
snd-usb-us122l: probe of 1-5:1.1 failed with error -22


i have tried googling these messages to no avail. i poked around
through the driver, i've tried some of the trouble-shooting tips
provided by the guy who originally
got the older models to work, removing echi-hcd, or unbinding it,
unplugging it, etc. but nothing seems to be making a difference.
Then my thought was that i need a proper asound.conf or .asoundrc.
because the soundcard seems to be available, when i unbind it and
unplug/plug the unit back in.
 i even tried removing them to see if on reboot, that they might be
reconfigured, but no luck.

if anyone can provide help, that would be greatly appreciated.   I
have a 30-day return, so if i can't figure it out, i will be returning
it
for a FFADO approved/fully-supported device. however that being said,
wouldn't it be nice to still take the opportunity to have this
device better supported or help debug some issues??

while i am not a really good programmer, i think i could be useful, as
i have this device in front of me
and can provide useful information to developers, just let me know
what you need!

Jordan

Re: Status of the Tascam US-122mkII???

[Daniel Mack]

On Sat, Jun 19, 2010 at 01:35:32PM -0400, jordan johnston wrote:
> Recently, i have gotten my hands on a Tascam US-122mkII.  i have done
> a lot of reading/googling and i can see that the device has been added
> to the snd-usb-us122l  and even-cross referenced my own device to make
> sure the Id and such were there.
> Currently, i am unable to get sound out of the Unit.   it does
> however, power up on boot.
> I have tried many things to get it working, and i have even gotten
> Jack to give me the option of picking this Device, however it shows
> errors
> and does not work :(

Could you please send the complete output of 'lsusb -v' with the device
connected?

Thanks,
Daniel

Re: Status of the Tascam US-122mkII???

[Daniel Mack]

(please don't remove any addresses from Cc:)

On Sat, Jun 19, 2010 at 01:58:02PM -0400, jordan johnston wrote:
>     Interface Descriptor:
>       bLength                 9
>       bDescriptorType         4
>       bInterfaceNumber        0
>       bAlternateSetting       0
>       bNumEndpoints           0
>       bInterfaceClass       255 Vendor Specific Class
>       bInterfaceSubClass      0
>       bInterfaceProtocol      0
>       iInterface              0
>     Interface Descriptor:
>       bLength                 9
>       bDescriptorType         4
>       bInterfaceNumber        1
>       bAlternateSetting       0
>       bNumEndpoints           0
>       bInterfaceClass       255 Vendor Specific Class
>       bInterfaceSubClass      0
>       bInterfaceProtocol      0
>       iInterface              0
>     Interface Descriptor:
>       bLength                 9
>       bDescriptorType         4
>       bInterfaceNumber        1
>       bAlternateSetting       1
>       bNumEndpoints           4
>       bInterfaceClass       255 Vendor Specific Class
>       bInterfaceSubClass      0
>       bInterfaceProtocol      0
>       iInterface              0

I just wanted to know whether they switched to class compliance
interfaces, but as you can see here, that's not the case.

> you will notice it is using usb 1.1 (i unbinded the usb2, as i am told
> it doesn't work with it)

How did you do this? And you modified the driver to match this device
ID, right?

> usb 4-1: new full speed USB device using uhci_hcd and address 3
> usb 4-1: New USB device found, idVendor=0644, idProduct=8021
> usb 4-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
> usb 4-1: Product: US-122 MKII
> usb 4-1: Manufacturer: TASCAM
> usb 4-1: SerialNumber: no serial number
> ALSA sound/usb/usx2y/usb_stream.c:603: status=-2
> ALSA sound/usb/usx2y/usb_stream.c:603: status=-2
> ALSA sound/usb/usx2y/us122l.c:365: us122l_start error -14
> snd-usb-us122l: probe of 4-1:1.1 failed with error -22
> usbcore: registered new interface driver snd-usb-us122l

Sorry, I can't help here. Maybe Karsten, die author of this driver,
has any clue (put to Cc: now). Otherwise, you would need to trace the
USB traffic using TASCAM's driver for Windows or MacOSX, and then
reverse-engineer the protocol ...

HTH,
Daniel

Re: Status of the Tascam US-122mkII???

[Daniel Mack]

Hi,

On Sat, Jun 19, 2010 at 02:30:03PM -0400, jordan johnston wrote:
> On Sat, Jun 19, 2010 at 2:09 PM, Daniel Mack <daniel@caiaq.de> wrote:
> 
> > (please don't remove any addresses from Cc:)
> 
> im not sure that  i follow what you mean here, can you explain???

Always use your email client's "reply-to-all" function, and do not just
send replies to me.

> ***  no i did not modify the driver to match this,  how do i do that???

Sorry, I didn't check properly. The driver clearly notes the
vendor/product ID of your device, that's why it is probed but fails.

This was added in commit 2b6f6c0d11 ("ALSA: snd-usb-us122l: add product
IDs of US-122MKII and US-144MKII"). Obviously, this patch wasn't tested
with real hardware (this is also what the commit log says), so it's no
surprise it doesn't work for you. I copied the author, and I'd vote for
reverting the patch until the driver is modified to actually support
what it claims to do.

> I set it to USB1.1  because i was under the impression that it will
> not work with echi_hcd,
> am i correct??

Well, according to the lsusb dump, the device is high-speed, so you
shouldn't need any tricks.

> my problem is that there really isn't any documentation that's
> up-to-date for this unit, the newest info i could find
> was a thread about the patches being submitted in December of last
> year.  but i figure by now that Zen should be up to date
> with the changes made, so i am still in the dark about this unit's status..

Who is Zen?

I think the answer to your question is quite simple but unfortunate:
TASCAM changed the protocol of the device in a newer version, and the
existing ALSA driver became incompatible with that. So there are only
two possibilites to fix this: either TASCAM will send patches to the
driver (which I think is unrealistic), or someone starts over and
reverse-engineers the protocol in order to make the driver support it.

As you happen to have the hardware - would you volunteer? :)

> Do you have contact information for him??  i am not sure how to go
> about the next steps you mention,
> but i would be more than willing to do what i can, if i was explained
> the process.
> like i said before i am not a good programmer, but i am decent enough
> with unix/linux and i do have XCode
> for OSX - if that's what i need for tracing?

Well, starting developing on the Linux kernel should be possible for you
then, and help is much appreciated :) There's a lot of documentation
around, and there is this and many other lists to get help on specific
topics. Just read Documentation/SubmittingPatches before you send :)

For tracing, you would either need a hardware analyzer (which you
probaly don't have) or a software tool. For Windows, tools like
http://www.usblyzer.com/ exist, but I never tried them myself. Maybe
give that one a try and analyze which packets go over the bus. As there
is no documentation, there is no other way than guessing what they're
doing. This can be really time-consuming and frustrating, unfortunately.

Good luck :)

Daniel

Re: Status of the Tascam US-122mkII???

[Tobias Hansen]

Daniel Mack schrieb:
>
> Sorry, I didn't check properly. The driver clearly notes the
> vendor/product ID of your device, that's why it is probed but fails.
>
> This was added in commit 2b6f6c0d11 ("ALSA: snd-usb-us122l: add product
> IDs of US-122MKII and US-144MKII"). Obviously, this patch wasn't tested
> with real hardware (this is also what the commit log says), so it's no
> surprise it doesn't work for you. I copied the author, and I'd vote for
> reverting the patch until the driver is modified to actually support
> what it claims to do.
>
>   
Yes, the driver doesn't work with the MKIIs. The patch can be reverted.

Greetings, Tobias

Re: Status of the Tascam US-122mkII???

[Tobias Hansen]

jordan johnston wrote:
> sorry about that....no more re-posting...
>   
Again, reply to all addressees of the mails, now you only replied to me.
> don't revert yet!!!
>
> The card IS half working, i can use midi no problem with jack...
>
> i think the driver DOES work..... i think the problem may be in
> .asoundrc or some other alsa settings.
>
> right now i am using .asoundrc that i had picked up from here:
>
> # got from http://www.nabble.com/tascam-us122l-and-ccrma-td24036395.html
> # thanks to Karsten
>
> # The usb_stream plugin configuration
>
> pcm.!usb_stream {
>         @args [ CARD ]
>         @args.CARD {
>                 type string
>                 default "0"
>         }
>
>         type usb_stream
>
>         card $CARD
> }
>
> ctl.!usb_stream {
>         @args [ CARD ]
>         @args.CARD {
>                 type string
>                 default "0"
>         }
>
>         type hw
>
>         card $CARD
> }
>
> i think the problem is that alsa/jack  don't know where to look for
> both the inputs and outputs (as midi works great).
> unfortunately, i have little to no experience with this, and am not
> sure how to proceed.
>
> it turns out that this card DOES use echi_hcd (i didn't unbind
> uchi_hcd this time).
>
> (dmesg)
> usb 1-5: new high speed USB device using ehci_hcd and address 3
> usb 1-5: config 1 interface 1 altsetting 1 bulk endpoint 0x83 has
> invalid maxpacket 9
> usb 1-5: New USB device found, idVendor=0644, idProduct=8021
> usb 1-5: New USB device strings: Mfr=1, Product=2, SerialNumber=3
> usb 1-5: Product: US-122 MKII
> usb 1-5: Manufacturer: TASCAM
> usb 1-5: SerialNumber: no serial number
>
> as you can see echi_hcd is being used and.....
>
> [ninez@ninez ~]$ ls /sys/bus/pci/drivers/ehci_hcd
> 0000:00:1d.7  bind  module  new_id  remove_id  uevent  unbind
>
> the card is found when you look for it!
>
> [ninez@ninez ~]$ cat /proc/asound/cards
>  0 [Intel          ]: HDA-Intel - HDA Intel
>                       HDA Intel at 0xefffc000 irq 27
>  1 [US122L         ]: USB US-122L - TASCAM US-122L
>                       TASCAM US-122L (644:8021 if 0 at 001/003)
>
> when i start Qjackctl up:
>
> jackdmp 1.9.5
> Copyright 2001-2005 Paul Davis and others.
> Copyright 2004-2009 Grame.
> jackdmp comes with ABSOLUTELY NO WARRANTY
> This is free software, and you are welcome to redistribute it
> under certain conditions; see the file COPYING for details
> JACK server starting in realtime mode with priority 89
> audio_reservation_init
> Acquire audio card Audio0
> creating alsa driver ... hw:0|-|128|3|44100|0|0|nomon|swmeter|-|32bit
> Using ALSA driver HDA-Intel running on card 0 - HDA Intel at
> 0xefffc000 irq 27             ***   using internal sound (bah!)
> configuring for 44100Hz, period = 128 frames (2.9 ms), buffer = 3 periods
> ALSA: final selected sample format for playback: 32bit integer little-endian
> ALSA: use 3 periods for playback
> Using port names patch v0.1 (07.04.2010)
> port created: Midi-Through:midi/playback_1
> port created: Midi-Through:midi/capture_1
> port created: TASCAM-US-122L:midi/playback_1
>         ***      it uses the midi just fine (i tested it with Native
> intruments, massive)
> port created: TASCAM-US-122L:midi/capture_1
> 15:46:49.327 ALSA connection change.
> 15:46:50.351 Server configuration saved to "/home/ninez/.jackdrc".
> 15:46:50.352 Statistics reset.
> 15:46:50.367 Client activated.
> 15:46:50.369 JACK connection change.
> 15:46:50.374 JACK connection graph change.
>
> if i set it to hw:1  jack can't start, nor does it matter if i am
> duplex, playback(only) or capture(only)..
> so i am convinced this driver can work, otherwise midi wouldn't work
> at all.   the problem is my configuration.
> but i am not sure how to remedy this, any clues would help! (let's not
> give up quite yet!)
>
> it's finding out how to tell it to use outputs and inputs properly.
>
> jordan
>   
MIDI works because it is done by another driver.

Follow these instructions to see if you can get the US122 MKII working 
like a US122L:
http://www.premiumorange.com/la-page-web-of-phil/index.php?page=P030101#conseils_installation

The interface is not hw:0 but usb_stream:1.

Also the US122L works with both ehci-hcd and uhci-hcd, the US144 only 
works with uhci-hcd.

Good luck, others tried it before and it didn't work.

Greetings, Tobias

Re: Status of the Tascam US-122mkII???

[jordan johnston]

Oops, sorry Tobias, i forgot to check it off. I did this time so
anyone can see. :)

So basically, many people have tried to get this working and
failed????  no one was able to get it working?

alright, i might setup a spare partition to give this another shot, as
i don't want to ruin my current setup that is needed every time
i got out and play music, or jam(like tonight!). My "Linux VST/live
input looper" must stay fully operational !
but i will probably take another shot at it. even though! - in the
end, i bet i am just going to purchase for FFADO "full-support".
i would buy HDSP, but it's a little pricey for my laptop.
I just thought that i would try to take advantage of the situation,
maybe help debug the driver, but if the implementation of the
us-122mkII is vastly different than what can you do??? It's too bad
that companies don't put more effort into supporting linux,
not that i need to tell you that!

On Sat, Jun 19, 2010 at 4:19 PM, Tobias Hansen
<Tobias.Hansen@physik.uni-hamburg.de> wrote:
> jordan johnston wrote:
>>
>> sorry about that....no more re-posting...
>>
>
> Again, reply to all addressees of the mails, now you only replied to me.
>>
>> don't revert yet!!!
>>
>> The card IS half working, i can use midi no problem with jack...
>>
>> i think the driver DOES work..... i think the problem may be in
>> .asoundrc or some other alsa settings.
>>
>> right now i am using .asoundrc that i had picked up from here:
>>
>> # got from http://www.nabble.com/tascam-us122l-and-ccrma-td24036395.html
>> # thanks to Karsten
>>
>> # The usb_stream plugin configuration
>>
>> pcm.!usb_stream {
>>        @args [ CARD ]
>>        @args.CARD {
>>                type string
>>                default "0"
>>        }
>>
>>        type usb_stream
>>
>>        card $CARD
>> }
>>
>> ctl.!usb_stream {
>>        @args [ CARD ]
>>        @args.CARD {
>>                type string
>>                default "0"
>>        }
>>
>>        type hw
>>
>>        card $CARD
>> }
>>
>> i think the problem is that alsa/jack  don't know where to look for
>> both the inputs and outputs (as midi works great).
>> unfortunately, i have little to no experience with this, and am not
>> sure how to proceed.
>>
>> it turns out that this card DOES use echi_hcd (i didn't unbind
>> uchi_hcd this time).
>>
>> (dmesg)
>> usb 1-5: new high speed USB device using ehci_hcd and address 3
>> usb 1-5: config 1 interface 1 altsetting 1 bulk endpoint 0x83 has
>> invalid maxpacket 9
>> usb 1-5: New USB device found, idVendor=0644, idProduct=8021
>> usb 1-5: New USB device strings: Mfr=1, Product=2, SerialNumber=3
>> usb 1-5: Product: US-122 MKII
>> usb 1-5: Manufacturer: TASCAM
>> usb 1-5: SerialNumber: no serial number
>>
>> as you can see echi_hcd is being used and.....
>>
>> [ninez@ninez ~]$ ls /sys/bus/pci/drivers/ehci_hcd
>> 0000:00:1d.7  bind  module  new_id  remove_id  uevent  unbind
>>
>> the card is found when you look for it!
>>
>> [ninez@ninez ~]$ cat /proc/asound/cards
>>  0 [Intel          ]: HDA-Intel - HDA Intel
>>                      HDA Intel at 0xefffc000 irq 27
>>  1 [US122L         ]: USB US-122L - TASCAM US-122L
>>                      TASCAM US-122L (644:8021 if 0 at 001/003)
>>
>> when i start Qjackctl up:
>>
>> jackdmp 1.9.5
>> Copyright 2001-2005 Paul Davis and others.
>> Copyright 2004-2009 Grame.
>> jackdmp comes with ABSOLUTELY NO WARRANTY
>> This is free software, and you are welcome to redistribute it
>> under certain conditions; see the file COPYING for details
>> JACK server starting in realtime mode with priority 89
>> audio_reservation_init
>> Acquire audio card Audio0
>> creating alsa driver ... hw:0|-|128|3|44100|0|0|nomon|swmeter|-|32bit
>> Using ALSA driver HDA-Intel running on card 0 - HDA Intel at
>> 0xefffc000 irq 27             ***   using internal sound (bah!)
>> configuring for 44100Hz, period = 128 frames (2.9 ms), buffer = 3 periods
>> ALSA: final selected sample format for playback: 32bit integer
>> little-endian
>> ALSA: use 3 periods for playback
>> Using port names patch v0.1 (07.04.2010)
>> port created: Midi-Through:midi/playback_1
>> port created: Midi-Through:midi/capture_1
>> port created: TASCAM-US-122L:midi/playback_1
>>        ***      it uses the midi just fine (i tested it with Native
>> intruments, massive)
>> port created: TASCAM-US-122L:midi/capture_1
>> 15:46:49.327 ALSA connection change.
>> 15:46:50.351 Server configuration saved to "/home/ninez/.jackdrc".
>> 15:46:50.352 Statistics reset.
>> 15:46:50.367 Client activated.
>> 15:46:50.369 JACK connection change.
>> 15:46:50.374 JACK connection graph change.
>>
>> if i set it to hw:1  jack can't start, nor does it matter if i am
>> duplex, playback(only) or capture(only)..
>> so i am convinced this driver can work, otherwise midi wouldn't work
>> at all.   the problem is my configuration.
>> but i am not sure how to remedy this, any clues would help! (let's not
>> give up quite yet!)
>>
>> it's finding out how to tell it to use outputs and inputs properly.
>>
>> jordan
>>
>
> MIDI works because it is done by another driver.
>
> Follow these instructions to see if you can get the US122 MKII working like
> a US122L:
> http://www.premiumorange.com/la-page-web-of-phil/index.php?page=P030101#conseils_installation
>
> The interface is not hw:0 but usb_stream:1.
>
> Also the US122L works with both ehci-hcd and uhci-hcd, the US144 only works
> with uhci-hcd.
>
> Good luck, others tried it before and it didn't work.
>
> Greetings, Tobias
>

thanks :)

jordan

Re: Status of the Tascam US-122mkII???

[jordan johnston]

hey,

should i report past messages for everyone to see?
(all my others were only to you, right?)

i don't know if anyone will find it useful or not...

jordan

Re: Status of the Tascam US-122mkII???

[Tobias Hansen]

jordan johnston wrote:
> Oops, sorry Tobias, i forgot to check it off. I did this time so
> anyone can see. :)
>
> So basically, many people have tried to get this working and
> failed????  no one was able to get it working?
>
>   
I know of two people who tried the US122MKII and two who tried the 
US144MKII and they didn't get it to work. Maybe the changes are not that 
big, but it needs someone who figures out what to change. (And maybe the 
protocol is completely different. - Like the US144 when it's on ehci-hcd.)

Greetings, Tobias

Re: Status of the Tascam US-122mkII???

[jordan johnston]

On Sat, Jun 19, 2010 at 4:58 PM, Tobias Hansen
<Tobias.Hansen@physik.uni-hamburg.de> wrote:
> jordan johnston wrote:
>>
>> Oops, sorry Tobias, i forgot to check it off. I did this time so
>> anyone can see. :)
>>
>> So basically, many people have tried to get this working and
>> failed????  no one was able to get it working?
>>
>>
>
> I know of two people who tried the US122MKII and two who tried the US144MKII
> and they didn't get it to work. Maybe the changes are not that big, but it
> needs someone who figures out what to change. (And maybe the protocol is
> completely different. - Like the US144 when it's on ehci-hcd.)
>
> Greetings, Tobias
>


hmm.... well, i will be taking it back next week, propably.  however,
i may get in contact with Tascam and atleast
let them know that people were able to use some of their products
under linux properly, until semi-recent changes to the product line.
that they should be putting some effort into having their devices work
in linux or at the very least, maybe provide the right linux
developers with some of the specifications.

I personally, won't be buying another Tascam product.

thanks for all of your help and clarifications.

I am going to have another stab at getting it to work, obviously i
will let you know what happens.
one thought i had was to patch echi_hcd on a more current kernel  (
those RPMs on the link you sent me, are super old ) .
as i use fedora 12 + 2.6.33  and i use alsa 1.0.23.

so obviously the Fedora guie is no good to me, reallly...

jordan

Re: Status of the Tascam US-122mkII???

[Daniel Mack]

On Sat, Jun 19, 2010 at 04:45:08PM -0400, jordan johnston wrote:
> So basically, many people have tried to get this working and
> failed????  no one was able to get it working?
> 
> alright, i might setup a spare partition to give this another shot, as
> i don't want to ruin my current setup that is needed every time
> i got out and play music, or jam(like tonight!). My "Linux VST/live
> input looper" must stay fully operational !
> but i will probably take another shot at it. even though! - in the
> end, i bet i am just going to purchase for FFADO "full-support".
> i would buy HDSP, but it's a little pricey for my laptop.
> I just thought that i would try to take advantage of the situation,
> maybe help debug the driver, but if the implementation of the
> us-122mkII is vastly different than what can you do???

Well, you can assume that audio is transported over dedicated
isochronous endpoints. The question is how audio parameters are set up.
And you can find out by tracing the traffic and see what happens when
you start or stop the stream, when you change the sample rate etc.

> It's too bad
> that companies don't put more effort into supporting linux,
> not that i need to tell you that!

The only thing you can do as a customer and end-user is to pay attention
to the state of Linux support of a new piece of hardware before you buy.

Or waste some weekends and help yourself and maybe lots of others ;)

Daniel

Re: Status of the Tascam US-122mkII???

[jordan johnston]

hey sorry,

gmail defaults to only you when i reply, EVEN when i am selecting "reply all".
i just have to add the Cc:  manually  :|    ( i wasn't taking anyone
out of Cc: )

sorry, i wasn't trying "violate" the rules or anything else, okay?

1. i understand that Zen-kernel has nothing to do with alsa, other
than sometimes alsa drivers for certain devices are available
in Zen before they are in my distro and many others i have used. i was
only explaining what Zen-kernel is and why i use it.
because you asked... makes sense?

2. I am glad that you were able to give me an update on the status of
these devices, as the documentation around the interweb,
is out-dated, and thus very often misleading.

3. I am going to go ahead and read all of the documentation you posted
links to, and i will see if i can figure out how it works.

4. I am also going to contact Tascam/Teac, as i am a paying customer -
why not :)    obviously they are unlikely to give a lot
of information away, but maybe i can get someone who knows just how
different(or similar) the implementation of
the Us-122L vs. mkII  really is.   either way, i don't mind sitting on
the phone for an hour or so  / or through  email  to let them
know they should support linux or at the very least work with ALSA a little.

it sounds like a lot of these companies could have really good support
under linux by A: providing info on the implementation
and B:  by handing a device or two, into the hands of the right
people(developers/hackers)...what a shame!

thanks again for all of your help.
It has been a slice!

jordan

Re: Status of the Tascam US-122mkII???

[Daniel Mack]

*** Reply to ALL please! ***

On Sat, Jun 19, 2010 at 06:51:58PM -0400, jordan johnston wrote:
> On Sat, Jun 19, 2010 at 6:41 PM, Daniel Mack <daniel@caiaq.de> wrote:
> > Well, you can assume that audio is transported over dedicated
> > isochronous endpoints. The question is how audio parameters are set up.
> > And you can find out by tracing the traffic and see what happens when
> > you start or stop the stream, when you change the sample rate etc.
> >
> 
> now, here you are referring, to tracing in OSX, or Windows right? (like before.)

Yes.

> i may try that out, but as i am not versed in this stuff it may be
> quite difficult
> without better understanding.
> 
> do you know of any really insightful information on the
> subject(somewhere on the net).
> im going to google around a bit too.

Hmm, I can point you to the USB specs which gives you detailed
explanation about the low-level communication on the bus:

  http://www.usb.org/developers/docs/usb_20_052510.zip

And you can read other Linux drivers and see what they do.

We have no clue what Tascam's engineers did when they designed the
MK2 version, and how close they kept to the protocol specs of their
earlier products. Maybe they just shifted some bytes around, maybe they
completely started over. All left for you to find out :)

> Ya, it was a gamble i had called the store earlier in the week, they
> actually had the device i wanted.
> however, i didn't end up going that day. so when i did come, it had
> been sold. i then decided to take
> a gamble on it.
> 
> no big deal. - 30 day return policy, and they said it was fine that i
> returned it, if i couldn't get it
> supported under linux.

It might take you more than 30 days to fully support it under Linux if
you're going to do it yourself though ;)


Daniel