[LAU] Motu Midi Express XT - parallel interface - ALSA

Daniel Appelt daniel.appelt at gmail.com
Wed Mar 17 12:08:14 EDT 2010

Hi there,

I recently found this message regarding the alsa setup of a parallel
port Midi Express XT when I was about to re-activate some old gear
myself. So, I subscribed to this list and have to admit that I found a
lot of interesting topics here in the last few days.. So, hello to

Regarding the Midi Express XT.. I finally managed to load up the
relevant alsa module when starting my (somewhat antique) desktop
system which runs a recent Arch Linux setup. The followings things
need to be taken care of:

1.) The relevant alsa module (snd-mtpav.ko) should come as a part of
most 2.6-kernels. Under a Xubuntu 7.10 (which I use on a laptop) the
module can be found in:
/lib/modules/<kernel version>/kernel/sound/drivers

So, most of the info found in
http://www.alsa-project.org/main/index.php/Matrix:Module-mtpav should
not be relevant for setting up the interface.

2.) The parameters for the module can also be found here:
Search for "snd-mtpav" in the text. The parameters "port" and "irq"
need to be provided in order to correctly load the module where port
refers to the address and irq to the irq (interrupt) which are
configured for the parallel port the midi interface is connected to.
For an on board parallel port these parameters should be configurable
in the PC's BIOS.

3.) The module snd-mtpav will only be loaded if it may get complete
control of the specified parallel port! This means that you should
have a parallel port on your PC which will be exclusively used for
this midi interface. Otherwise, you would need to manually load/unload
relevant kernel modules. I think this is due to the way the module is
programmed, but that this is not necessarily the only possible
solution. For example, the module for the Portman 2x4 interface
(snd-portman2x4) uses another way to gain access to the parallel port
which seems to be more user-friendly if you want to connect another
thing to the parallel port like a printer (if such devices still
exist) at run-time...

4.) Regarding items 2.) and 3.) you need to do the following in order
to set up the Midi Express XT: Find out how to load a module at system
start up, and how to prevent the kernel from auto-loading some
standard parallel port modules. In Arch Linux this is simply a matter
of editing the "MODULES" line in /etc/rc.conf. For an Ubuntu-based
distribution you should find a solution at the Ubuntu user's wiki, or
in one of the numerous Ubuntu forums.
You want to load the module snd-mtpav, but you do not want the kernel
to automatically load the modules lp, parport, and parport_pc (at
least, if you only have a single parallel port on your PC)! This way,
snd-mtpav should get exclusive access to the parallel port.
Additionally, the parameters for snd-mtpav need to be provided. In
Arch Linux the relevant file is /etc/modprobe.d/modprobe.conf. Under
Ubuntu, I suppose you need to edit/create a file in /etc/modprobe.d/.
The relevant info including the exact file name should be present in
the user's wiki/forums too.
On my system I added the following lines to modprobe.conf in order to
determine a static "sound card" order, and the parameters for

options snd-ice1712 index=0
options snd-mtpav port=0x278 irq=5 index=1

5.) Reboot your system and use the "dmesg" command in order to check
the kernel startup messages. If all went well, it should include a
line like "Motu MidiTimePiece on parallel port irq: 5 ioport: 0x278".
Furthermore, "cat /proc/interrupts" should produce a line like "5: ...

Hope, this helps in some way..

Kind regards,

More information about the Linux-audio-user mailing list