cheap pci sound card with full duplex support?

[Roland Dreier]

I would like to get a sound card that can do full duplex under linux (ie
open /dev/dsp with mode O_RDWR).  I see cards like the "Ensoniq AudioPCI"
for around 20 bucks that claim to do full duplex, but I don't know whether
there's a linux driver.

So, my question: are there sound cards (preferably PCI) for around $20
that have full duplex support under linux?  Are the drivers free?

Thanks,
Roland
[EMAIL PROTECTED]