The up and down arrow keys have little orange suns painted on them to match the orange Fn key.
In Linux Mint, these brightness keys work OOB. Pretty sure that's what they're meant for in windows.
With the debugging VoodooPS2 kext,
Fn+Insert gives ApplePS2Keyboard: sending key 46=6b down
Fn+Home gives ApplePS2Keyboard: sending key e045=71 down
Fn+uparrow does not generate a ps2 scan code
Fn+downarrow does not generate a ps2 scan code
uparrow gives ApplePS2Keyboard: sending key e048=7e down
downarrow gives ApplePS2Keyboard: sending key e050=7d down
Looks like it's gonna have to be the ACPI debug way. I think I see what to do based on the instructions you gave in several other threads. I just have to determine which _QXX methods to replace.
Code:
into method label _Q10 replace_content
begin
// Brightness Down\n
Notify(\_SB.PCI0.LPCB.PS2K, 0x0205)\n
Notify(\_SB.PCI0.LPCB.PS2K, 0x0285)\n
end;
into method label _Q11 replace_content
begin
// Brightness Up\n
Notify(\_SB.PCI0.LPCB.PS2K, 0x0206)\n
Notify(\_SB.PCI0.LPCB.PS2K, 0x0286)\n
end;