This is for the Dell Inspiron 1520 Laptop, Core 2 Duo T7250 mobile cpu, nVidia GPU/Graphics.

Very Important notes regarding this Laptop!!!

The ICH8 Intel GM965 chipset in this has known issues with video bios as Intel made a boo boo with the memory management, if you are on a BIOS Version lower than A09 i'd advise updating ONLY if you have had no issues in Ms Vista 32bit that shipped originally with this laptop. The A09 bios contains the video bios update from Intel that is supposed to fix the memory management errors indicated by many random BSOD's running Vista, even downgrading to XP.

There were many problems with this laptop, just google and you'll see, Dell really dropped the ball on this laptop IMA this was an awful product and they should be ashamed.
This model suffer from over heating, noticeable your laptop seem really hot to touch, the Dell Bios A09 for the Inspiron 1520 doesn't contain any HPET's (High Precession Event Timer) so you will need 'NullCpuPowerManagement' or osx will kernel Panic on 'No HPETS'.
Function keys are working... (Brightness, Volume, etc)

[Added Modified Voodoo HDA 2.7.3 kext & LSPCI output for this laptop too] *** No Guarantee this will work with your Inspiron 1520 ***