[openbeos-midi] Re: mpu401 module

  • From: Crain Greg <greg.crain@xxxxxxxxxxx>
  • To: "'openbeos-midi@xxxxxxxxxxxxx'" <openbeos-midi@xxxxxxxxxxxxx>
  • Date: Mon, 13 Jan 2003 13:09:17 -0500

-----Original Message-----
From: Philippe Houdoin [mailto:philippe.houdoin@xxxxxxx]

>First, it seems that the mpu401->open_hook() send you to frozen land here.
>Did you check the card.midi.driver value here? Is it still the same value 
>than after a successfull mpu401->create_device() call?

>Second, check that the port address you pass to create_device() is the right 
>one. There is also this weirdo "workaround" argument in create_device(), too...

Yea, the address was the problem.  I was using the data port ( A_MUDATA = 0x70 
offset)and I should have been using the command port (A_MUCMD = 0x71 offset).  
So, the open hook sends a reset, and also sends the command to go into UART 
mode.  The mpu module does spit out a few debugging messages.  Everything 
appears like it should be working now, except I see no MIDI data.  I don't know 
if the mpu module knows that the data port is the command port - 1.  I think it 
might be standard.  I found some old documentation from Creative, and it was 
typically port address of 0x330, and 0x331 consecutive addresses. 
It looks like it is probably a driver issue at this point, but learning how it 
all works is probably a good thing for the midi kit :-)

Thanks for the suggestions-
Greg Crain

Other related posts: