Yooo!

Update 10/11/12 : I finally got a working rom that will work with the card im currently flashing in this tutorial. If your card is a Radeon 9800 and it's based off the XT board design, you will need to use the Modified PPC ATi rom. It is 128K in size, and I didn't find a "reduced" version that is V130. So head on over to Mac Elite and pick up the Radeon 9800 256MB hack Version 130... Version 130 were the only ones to work with these XT board designs that had 256MB. Now you know. :)

**MorphOS will only see 128MB total, but booting into Mac Installer, it sees all 256MB.**

***There are some 9800 PRO cards that have 16 memory chips on them to make 256MB, but as of now, there is no working rom for them as they will only show a corrupted graphics screen. I have no idea if you can flash the card with a 128MB rom and be ok, but be warned!***

**Before getting started, I remove the resistors from the cards because I do not own any ADC compatible monitors, so instead of taping over/scraping at the traces, I simply removed them. Whichever method you prefer, just find a way to disable pins 3&11 from back of the card.**


So this isn't quite a "Complete" tutorial to flashing a Radeon card, but this is one that will hopefully help someone out there that might develop quite a headache.

First things first, I won a Radeon 9800 PRO 256MB card off ebay ($20 after shipping) and finally arrived in the mail today. There were a few differences between my previous Radeon 9800 PRO 128MB card, as you see in these picture:

cardsfront.jpg

cardsback.jpg

The one I labeled XT is the Radeon 9800 PRO 256MB, but its reference design is based off the 9800 XT board. No biggie, so I figured the locations to desolder resistors R2 and R4 on back were at the same spot, but they were not! I tracked down where Pins 3 & 11 were going, so if you have the XT design, these are the two you want to desolder from the back:

xtboardr2.jpg

xtboardr4.jpg

**After looking at another 9800 XT mac edition, R5 and R6 are intact... I would't bother removing them... Though another guide said to remove them.

xtboardr5r6.jpg

Almost there! This was the part I had quite the headache. I went over to Mac Elite and downloaded the Radeon 9800 PRO 256MB rom (the 128k sized one) and flashed it over to the 256MB Radeon I have, it programmed with success. I swapped the card over to my MDD Mac, and WHAP! CORRUPTED graphics! ARGH!! Tried out a 9800 XT bios, and same story, more corrupted graphics. Tried the "reduced" roms as well, and same story.......

So after doing a search, It turns out that someone had terrible luck flashing the Radeon 9800 PRO 256MB card Version 134.... It gave them garbage on the screen, but turns out with the PREVIOUS 130 version, everything was A ok! So my luck I didnt bother to try out the previous version of the Mac Bios on this 256MB Radeon. I went ahead and flashed this bios from Mac Rumors (Download the 130 bios from there). This is a 128MB version of the bios, use get27's links for the 256MB bios. Scroll down for his post.

To my amazement, it worked! Turns out some 9800XT boards hated certain Mac bios. Either way, hope this helps someone out. Just getting ready for the R3xx drivers to be released.

Enjoy!

**It came to my understanding that some PRO and XT cards had a 64KB flash on them, and some with 128K flash. Some SST flash were labled 64KB, when infact they are 128K! To be on the safe side, just flash the reduced Radeon 9800 PRO 256MB Version 130 if you are having issues. My other 128MB Pro card flashed fine with the latest v134.**

[ Edited by Doffo 11.10.2012 - 21:59 ]