onboard sound does not work

[by way of Gaf <moak at bredband.net>]

Hello.
I am a newbie to both unix and FreeBSD. I am trying to configure my onboard
sond without success.
 My motherboard: ASUS P4S800-MX
Audio spec: ADI AD1888 6channel audio codec.

pciconf -lv says:
pcm0 at pci0:2:7:  class=0x040100 card=0x810d1043 chip=0x70121039 rev=0xa0
hdr=0x00
    vendor   = 'Silicon Integrated Systems (SiS)'
    device   = 'SiS7012 PCI Audio Accelerator'
    class    = multimedia
    subclass = audio

dmesg:
pcm0: <SiS 7012> port 0xa000-0xa07f,0xa400-0xa4ff irq 18 at device 2.7 on
 pci0 pcm0: <Unknown AC97 Codec (id = 0x41445368)>

I tried kldload snd_driver.ko but
kldstat says:
Id Refs Address    Size     Name
 1   35 0xc0400000 37fd84   kernel
 2    1 0xc0780000 51a18    acpi.ko
 3    1 0xc2c24000 8000     ipfw.ko
 4    1 0xc2c62000 19000    linux.ko
 5    1 0xc3306000 2000     snd_driver.ko
 6    1 0xc3308000 8000     snd_maestro3.ko

I have device pcm in my kernel.
Is there something more you need to know??
I have read man pcm, the handbook and complete freebsd but I can t figure it
out. I still think that everything is a bit confusing because i am not very
good at computers and i am sure that I miss something fundamental.
Hope that somebody can direct me to what i am missing.
Many thanks Gaf