Full duplex using 2 sound cards.

Ian Main (imain@vcc.bc.ca)
Tue, 28 Jan 1997 00:14:40 -0800 (PST)

Hi, as you guessed, I'm trying to get full duplex sound using 2 sound
cards. One is a mad16, and the other a sb16. Both work fine by
themselves, but when I try to use them together, the sb16 behaves a little
strangely. (mad16 works fine.) The sb16 works fine for 8 bit IO, but 16
bit playback and record is very jumpy. It misses large sections of the
sound (I assume it's a buffer problem.)

I thought the 2 cards would work ok together since they use different IO
ports, dma's and irq's, but I can't seem to get them to work together.

I'm trying to write a 8 track like program (or however many tracks) that
requires full duplex, and 16 bit sound quality would be very nice.

I've been trying to get this to work for a few days now. I tried
compiling as modules, and in the kernel, using as many combinations of
dma's as I could think of. (irq's seemed fine to me.)

oh! and if there's a way to pass arguments to the sound driver to change
the irq's/dma's/first initialized sound card etc. through lilo or the
insmod command line ?

Any suggestions/help would be greatly appreciated.

Thanks a tonne!


PS. Here's an output /dev/sndstat with the best combination I've found so
far. The sb16 only misses about half of the playback with this setup. (I
checked, the same file played back in the same mode on the mad16 works
fine, so it's definately just something wrong with the sb16 setup.)


Sound Driver:3.5.4-960630 (Mon Jan 27 23:47:19 PST 1997 root,
Linux Slow 2.0.28 #10 Mon Jan 27 20:10:56 PST 1997 i486)
Kernel: Linux Slow 2.0.28 #10 Mon Jan 27 20:10:56 PST 1997 i486
Config options: 0

Installed drivers:
Type 19: MAD16/Mozart (MSS)
Type 20: MAD16/Mozart (MPU)
Type 2: Sound Blaster

Card config:
MAD16/Mozart (MSS) at 0x530 irq 11 drq 3,0
(MAD16/Mozart (MPU) at 0x330 irq 9 drq 0)
Sound Blaster at 0x220 irq 5 drq 1,5

Audio devices:
0: MAD16 WSS (CS4231) (DUPLEX)
1: Sound Blaster 16 (4.11)

Synth devices:


0: System clock
1: MAD16 WSS (CS4231)

0: MAD16 WSS (CS4231)
1: Sound Blaster