Hey Amigo and Gordon: you two seem to be the gurus here on GPU mods.
I need to change one single bit to fix a problem but I'm stuck.
I bought a used GTX 580 but someone had changed the Device ID from 1080 to 1090. I just want to change it back to 1080.
From my .rom file, in lines 50 and 60, converted to little endian I get:
FFFF FFFF 0000 0000 7FFF FFFF 8000 0000
My rom is from here:
http://www.techpowerup.com/vgabios/114426/MSI.GTX580.1536.111011.romgoing from
1090 = 0001 0000 1001 0000
to
1080 = 0001 0000 1000 0000
since the digit to be changed is the 5th from the right, it means that only the bit in location 4 needs to be changed as in this template:
-xx4xxxx xxxxxxxx xx3210xx xxxxxxxx
Therefore, I can either make that
ONE SINGLE change in the AND-0 like this:
Old Strap:
AND-0: FF FF FF FF
1111 1111 1111 1111 1111 1111 1111 1111
OR-0: 00 00 00 00
0000 0000 0000 0000 0000 0000 0000 0000
New Strap:
AND-0: EF FF FF FF
1110 1111 1111 1111 1111 1111 1111 1111
OR-0: 00 00 00 00
0000 0000 0000 0000 0000 0000 0000 0000
or, I can make
ONE SINGLE change in the OR-0 like this:
Old Strap:
AND-0: FF FF FF FF
1111 1111 1111 1111 1111 1111 1111 1111
OR-0: 00 00 00 00
0000 0000 0000 0000 0000 0000 0000 0000
New Strap:
AND-0: FF FF FF FF
1111 1111 1111 1111 1111 1111 1111 1111
OR-0: 10 00 00 00
0001 0000 0000 0000 0000 0000 0000 0000
If it's in the AND portion:
nvflash --index=1 --straps 0xEFFFFFFF 0x00000000 0x7FFFFFFF 0x00000000
if it's in the OR portion:
nvflash --index=1 --straps 0xFFFFFFFF 0x10000000 0x7FFFFFFF 0x00000000
Problem is, I've tried both and nvflash says that my straps are out of range.
Any advise?