3 soundcards

hello

i've got 3 soundevices on my computer

1) onboardsound
2) pci-soundcard
3) webcam (the microphon)

all these devices are running wihtout any problems. the problem ist that i can
not  use all devices at the same time. i think that i've got not enough sound
devices in the /dev/ directory.

i 've got only devices for two sounddevices
mixer
mixer1

can someone tell me how to create the files (newbie) for a third sounddevice? i
read the manual from MAKEDEV but i haven't found any parameters that added me a
 new sounddevice.

thanks

martin