A Flasher's Buying Guide - ATI Radeon 9600 Series
All Radeon 9600 cards are 8x AGP enabled, and need to have pins 3 and 11 disabled in order to work in 4x AGP ADC-capable G4 Macs (Digital Audio, Quicksilver, Mirrored Drive Doors, FW800)
9600 Pro/XT 64/128MB BGA RAM
Core speed: 350-500MHz
RAM speed: 300MHz DDR
Pipelines: 4 (full)
Memory bus: 128-bit (full)
AGP: 4x + 8x Compatible - Digital Audio & newer Tower G4's and Tower G5's with AGP slots
Note: Cards (such as the one pictured) with only one gap ("key") in the gold AGP connector are 4x/8x Compatible only, and will work only in G4 Towers Digital Audio (466+MHz) and newer, as well as G5's.
Ports: DVI-I, VGA, and S-Video Analog Video Only
G4 Cube: Not compatible.
ROM chip: 64 or 128k
Full ROM: 9600 Pro 126 ROM or 9600 XT 121 ROM
Notes: If your 9600 Pro or XT card looks like the one pictured above, it is one of the only models flashable for your Mac. The exact board layout should not matter, but the important part is that the card uses square, "BGA" RAM chips, two each on the upper and right sides of the GPU, exactly as shown above. VGA will work (and might give poor quality picture, lavished brigthness and colours), and using a DVI->VGA adapter on the DVI port will yield a second VGA output (with clear and good quality picture), but digital DVI will not work. S-Video will not work unless Apple's DVI to S-Video adapter is attached to the DVI port. Then, the card's onboard S-Video port will be enabled. It is possible that this type of card could be flashed with the 9600 Mac/PC ROM, and it might even work in a PC if you do so. It's been tried once on a Hercules 9600XT 128Mb BGA RAM and produced puzzled display in Mac. You may have more luck with a 256MB BGA RAM Radeon 9600Pro/XT.
9600 (any suffix) TSOP RAM
Notes: This type of 9600 card is not usable once flashed. The cards all use cheaper/slower RAM chips than other 9600 cards, and no ROM currently exists that will work on this card. The 9600 SE also uses a 64-bit memory bus, opposed to the standard 128.
Pictures taken from iXBT: http://www.digit-life.com/
These guys take lots of high-res pictures and scans of video cards, and are a good resource to the modding community.