Howto install:
- choose and download kexts pack for ALC1200
- remove VoodooHDA ALCinjector.kext AppleHDA.kext (don't remove this if you're installing legacy version) ALC1200fix.kext and any audio kext you could have installed in /Extra or in /System/Library/Extensions
- unpack the zip file
- run kexthelper
- install kexts
- reboot


Obviously backup kexts you need.

====Q/A====
Q: What happens when I commit an update, for example from 10.6.1 to 10.6.2?
A: You must reinstall those hacked kexts, because the update overwrite the vanilla hacked applehda kexts.
Should even happens that the update doesn't overwrite the old applehda kext driver, so in this case, you don't need to reinstall.

Q: I'm experiencing pop sound, how can I solve this?
A: Try setting your hack as MacPro3,1 in /Extra/smbios.plist

===========


==================== SNOW LEOPARD and LION ==========================
**First method**with DSDT Injection, patched AppleHDA, and NO HDAenabler attached.Attached File  AppleHDA_ALC1200_HDEF.zip ( 1.7MB ) Number of downloads: 3931
remove AppleHDA.kext from /S/L/E and install this after dsdt edit.
HDEF code is attached in the zip pack, put the HDEF code in:
- SCOPE _SB
-- Device PCI0
--- Device HDEF

**Second method**easier, no quality differences: with HDAEnabler and no DSDT editing.[latest] ==> ALC1200 for Lion 10.7 and Snow Leopard 10.6.3, 10.6.4, 10.6.5
Attached File  ALC1200_1063.zip ( 1.67MB ) Number of downloads: 15514
==================================================

older 10.6x versions:
- SL 10.6.2 modded kexts
Attached File  ALC1200_1062.zip ( 1.27MB )

- Snow Leopard 10.6.0 and above ALC1200 audio kext:
Attached File  ALC1200_106.zip ( 1.11MB ) 


==========OLD STUFF==========
ALC1200 driver for 10.5.x :
I think latest ALC1200_SLIM version could be considered "final", I'm running 10.5.6 and I'm working on this OSx version.
For previous OSx version you can try installing only the ALC1200fix and the HDAEnabler from ALC1200_1056LINEIN version and see if that works.
The other ALC1200 kext versions out on the forum are old and I think can even cause some shutdown/reboot issue.
This driver doesn't work with ALCinjector.

- SPDIF coaxial Digital Out working
- Headphone working
- Line in is working only in the slim and line-in version, read notes down this post

-----------

Works on 10.5.7, just download and reinstall the driver.
Choose driver version, I think best choice is the slim version:
1. Update (4th june 2009) slim version from 10.5.7 applehda with: green line out, headphones, rear mic, line in and spdif out
I removed not needed verbs for multiple channel output (I don't need them)
Attached File  ALC1200_1057_SLIM.zip ( 624.87K ) 
4th june 2009 10.5.7 version [latest]

----
Attached File  ALC1200_SLIM.zip ( 805.01K ) 
[/b] 19th april 2009 10.5.6 version (discontinued)
2. Normal version with no line-in, you can switch between front/rear mic without any trouble
Attached File  ALC1200_1056.zip ( 819.55K ) 


3. This is a beta version with all three input working, line-in, front mic and rear mic, front-mic has some trouble tongue.gif 
This version works but if you switch between inputs, front mic stops working (only for that session obviously, if you reboot it works). This happens because ALC1200 has 1 digital mixer node for 2 channel (linein and front mic) instead of one, so if you come back from line-in input, to front mic, front mic stops working.
At the moment I would think this driver can't manage thing like this, so I don't know if we could have a better driver than this.
Anyway I wanted a working line in and if you select this and use it, that works, so if you need line-in you should use this version. wink.gif 
[attachment=48413:ALC1200_1056LINEIN.zip]
Update (14th april 2009) with RCA spdif in "about this mac"
Attached File  ALC1200_1056LINEIN.zip ( 823.28K ) 


Update (17th april 2009) removed ALC1200fix.kext from the pack
Attached File  ALC1200_1056_LINEIN.zip ( 810.61K ) 

If you're updating your driver, in order to install this, remove ALC1200fix.kext from your extension folder, then install this with kexthelper.
Now in sound preference there's no (useless) "Internal speaker" "Built in" for input and output.
Attached File  input.jpg ( 51.01K ) 



Device informations:
CODE
Realtek ALC1200
00:1b.0 Audio device [0403]: Intel Corporation 82801JI (ICH10 Family) HD Audio Controller [8086:3a3e]
Device ID: 0x3a3e8086


You can find ALC1200 on:
Asus P5Q tested ok
Asus P5Q3 tested ok
Asus P5Q-EM tested ok
Asus P5Q-VM tested ok
Asus P5QL-EM tested ok
Asus P5Q-Pro tested ok
Asus P5Q-SE tested ok
Asus P5Q-SE/R tested ok
Asus P5E3 PRO tested ok
Asus P5Q-C tested ok
Asus P6T tested ok
Asus P6T-SE tested ok
Asus P5QL-PRO tested ok
Asus P6T deluxe
 it's an AD2000b!
Asus M3A78-EM
 it's an ALC888!
Asus P5N7A-VM 
tested ok
Asus P5QL-E tested ok
Asus M3N78-EM tested ok
Asus M3A-H/HDMI
Asus M3A78-T
Asus M3A78 PRO
Asus P2-M3A3200
Asus M3N78-EM
Asus P2-M3A3200
Gygabyte GA-EP43-S3L tested ok
Gygabyte GA-EP43-DS3L tested ok
MSI P45 NEO3-FR tested ok
MSI P43 tested ok