Firmware update to fix 3 GB memory barrier
It appears that some iterations of this version supported only 3 GB of RAM (mine), and some later ones supported 4 GB. The very similar A1226 supported up to 6 GB supposedly.
Is there an unpublished firmware update that will get me up to the 4 GB usage at least? Would it be possible to apply a firmware for a very similar but later Mac to this one and have it work (I know this won't work for systems that are different)?