Re: Questions about soundcard discovery

On Tue, 14 Feb 2006, Steve Campbell wrote:

> The PC orignally had an on-board soundcard, which did not seem to
> work. I disabled that and replaced it with another type of sound
> card, and it too would not work.

Do you have a cable connecting the CD drive to the sound card ? This 
can be either a 4 pin one (analog) or a 2 pin one (digital); on the CD 
drive the connection is usually to the left of the IDE cable one.

> I can not even listen to the CD directly from the CD drive with
> headphones, but the CD player will read the disc fine, it just won't
> play.

This is a bit confusing. How do you know that the "player will read 
the disc fine" ? There are 3 ways of listening to a CD:
- connecting an external device (headphones, stereo, etc.) to the 
external jack connection on the front of the CD drive. The CD player 
program only needs to give commands to the drive as to what/when to 
play/stop, etc. and read some data about the actual position/time if 
needed for display.

- connecting a sound card to the audio connection on the back of the
CD drive (which I mentioned above); then the external device
(headphones, stereo, etc.) is connected to Line Out of sound card.  
The CD player program does the same as previously.

- using the IDE connection to transfer audio data from the CD drive to
the main memory then playing it back through the PCM/Wave channel of
the sound card. The external devices are connected to Line Out of
sound card. The CD player program has to do all the data reading from 
the CD drive and playing through the sound card, which makes for a 
significantly higher CPU usage, especially if the CD drive is used in 
PIO (as opposed to DMA) mode (hdparm -vi /dev/hdX can tell if DMA is 
currently used). I think that xmms can be used as a CD player in this 
mode.

In the first 2 cases, there is a volume control on the drive itself 
that can be controlled normally through the CD player program; this is 
an internal drive control, not to be confused with the external one 
that can be used to control the volume in the first case.

So, which ones have you tried ?

> But "Soundcard Discovery" never finds anything once the system is up
> and running.

It's possible that both (all) sound cards are not properly supported 
by the kernel. What distribution version are you using anyway ?

-- 
Bogdan Costescu

IWR - Interdisziplinaeres Zentrum fuer Wissenschaftliches Rechnen
Universitaet Heidelberg, INF 368, D-69120 Heidelberg, GERMANY
Telephone: +49 6221 54 8869, Telefax: +49 6221 54 8868
E-mail: Bogdan.Costescu-PDzUyZpvkMP/PDbm/[email protected]