BCM94312MCG (aka BCM4312, BCM4314A) works great on SL 10.6.3, here's brief instructions:

[acamar]

My configuration:

 

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Notebook: T400

 

WLAN Card: BCM94312MCG

* Install a hacked BIOS to enable replacement of new BCM4312 mini pci-e WLAN card

 

OS: iATKOS S3 with 10.6.3, Default installation

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After installation, BCM4312 recognized in system profile with id "pci14e4,4315", but airport can't find any device. After several attempts to fix that issue without success. Finally, I saw a post from gprince , "http://www.insanelymac.com/forum/index.php?showtopic=140056", he wrote:

 

"Open a terminal and type:

sudo nano /System/Library/Extensions/IO80211Family.kext/Contents/PlugIns/AppleAirPortBrcm4311.kext/Contents/Info.plist

type your password

replace 4318 by 4315 (should be the device id)

ctrl O to save, ctrl X to quit

sudo touch /System/Library/Extensions"

 

I just followed the steps, then,

 

In system preference/network, Add the airport connection, manually configure IP address, and wireless connection worked at once.

 

I know many people succeed in same way, but there are many more people don't know it yet. There is two much misleading information over the net. Many of them gave up of hope on BCM4312.

 

I post this just to confirm that, BCM94312MCG/BCM4312 can be used in snow leopard 10.6.3, if you follow above instruction.

 

Attached is the modified IO80211Family.kext which had been modifed by me.

 

Hope this post helps.

IO80211Family.kext.zip