What processors does bios support?

I have an Inspiron 1420 with the latest BIOS A04 and was wondering if there was any way to determine just what processors this supports? If not does anyone know? I am currently running a T5250 and following my one year warranty expiring I want to know what cpu I can upgrade to. I know for sure that I can go as high as the t7500 but want to know if anyone knows if it can go to the t7700 or the new penryn chips. I will soon be doing a bunch of video encoding that I wasn't planning on doing when I first bought the Inspiron and can't really afford to buy a new system at this point.