Mmm, I think the short answer is no.
A longer answer is if you understand machine code, or at least assembly language, and the possible BIOS related functions of that motherboard, and by disassembling the BIOS code could determine whether there are in fact any extended functions that could be accessed by activating a menu, then maybe something could be done without turning the board into a doorstop. But not just by accessing files with a hex editor.
Whether the memory capacity of a board can be increased with a BIOS modification depends on where the limit occurs. If it is determined by the BIOS itself, then a change in the BIOS can remedy it. If the limit is set by the design of the support chipset, ie the memory controller, or the motherboard design, ie the number of address lines existing, the BIOS cannot alter that.
Edited by Platypus, 08 November 2009 - 05:28 AM.