The challenge about unlocking the version of the card that I got in the mail is that the flash chip needs to have write protect disabled.
Adapted from this: http://www.techpowerup.com/articles/overclocking/vidcard/159
I don't run Windows on my mining rig. If you do things are much easier than what I did. This is about what I did, not necessarily the easiest way for you. I use ATIFLASH in DOS, you can use whatever flash utility you want. You will also need RBE (which requires windows). I use mac/unix so I made a bootable USB drive with an UBCD iso and UNetBootin (http://unetbootin.sourceforge.net/
). On that flash drive I made a directory called ATI where I installed ATIFLASH. For RBE (http://www.techpowerup.com/downloads/Utilities/RBE/
) I used a Windows virtual machine on my Mac.
The basic process is this:
Boot into DOS download the flash from the card:
ATIFLASH -s 0 A0-ORIG.ROM
(change 0 to whatever position your card is in)
Then in windows use RBE to unlock shaders; save the ROM as A0-UNLCK.ROM
Jumper pins 3 and 8 on the flash chip. Someone on IRC pointed out that I should use a pull up resistor. Well I am very lazy and I wanted to leave the mod in place so this is what I did. I got a circuit writer pen (http://www.amazon.com/CircuitWriterTM-Precision-Pen-silver-based-grams/dp/tags-on-product/B0002BBVQO
) from Radio Shack. I covered the top of the flash chip with a regular pencil (like the ones you use to take a scantron test). I then used a dab of circuit writer pen to connect pin 3 and 8 to the top of the chip. The graphic from the pencil acted like a resister.
There is discussion about identifying the chip and the correct pins here: http://www.techpowerup.com/forums/showthread.php?t=146951
I then booted back to DOS and use ATIFLASH to write the modified BIOS back to the card:
ATIFLASH -p 0 A0-UNLCK.ROM
I have had mixed results. The first board I did went well and it has a stable 303MH/S with 840 OC Core (I know people go much higher than this but I am running this at 45C ambient. The second card doesn't maintain a very stable hash rate. This may be caused by me trying to flash the card without the cooler attached. I may have damaged something.