So a few days ago a bunch of new soldering equipment i ordered arrived (mostly for another big project that ill be undertaking once that main part for that arrives) and one of the things i wanted to do with this was solder a larger (128K) ROM chip to my FireGL X3 and flash it with an X850XT ROM for faster speeds.
now as a few know you can flash a X800XT ROM to a FireGL X3 to turn it into a Mac X800XT now you have to flash it with a reduced ROM as the stock EEPROM (ROM chip) is too small to take the full ROM now this works because the X800XT was a retail card and there for ATI included the component that was removed to reduced the ROM as a piece loaded off the HDD as part of their software suit (specify you removed the NDRV to reduce the ROM) Now ATI only included the external NDRV for Cards that where sold via retail. OEM only cards never got an external NDRV and had to rely on the one already in ROM or one Apple placed in the OS. this is why for example there was never a reduced X850XT ROM you can reduce it but without an NDRV things dont work very well (you can end up with the broken grayscale seen sometimes, or your stuck to one screen res and it does not detect your monitor properly and the mouse curser is flickery).
now the way to get around this is to of corse solder on a bigger EEPROM that can take the Full Fcode Mac ROM. so thats what I set out to do. first I needed a larger EEPROM so I decided to use a Radeon 9000 Pro from an MDD for its EEPROM (that i also discovered only saw half its VRAM...) so I took the Card and flashed it with the normal FireGL Reduced rom (as a fail safe a known working firmware) then I Desoldered the EEPROM from it using a 858D SMD rework station/hot air gun then I took the FireGL X3 located its EEPROM (its under the heatsink) and removed its smaller EEPROM (which had a ROM that actually bricked the card but thats another story so by replacing the EEPROM i was also unbricking the card) then i soldered on the bigger EEPROM by placing it on the pads and reflowing it on with the same hot air station.
Here is a picture just after reworking the new EEPROM onto the board (the EEPROM is the chip marked U11)
after it cooled I put fresh thermal paste on and put the card back together then put it in my G4 turned it on aanndd Nothing. not one to be defeated I took the card back out took it apart made sure i did not put the EEPROM on the wrong way round. then Took my soldering iron (a digital 936 clone) and touched up the pins put the card back together into the G4 and turned it on... and BINGO it booted up all the way to the desktop woo!
now this was still with the reduced X800XT ROM so I then took the full sized X850XT Mac rom modified its 2 Device ID entries in a hex editor so it worked with the FireGLs Device ID (the same thing was done to the FireGL X800 ROM everyone uses) the I flashed the full ROM and the ATI flasher said it flashed with no problems so i rebooted and moment of truth.... i got a bong and then a Boot screen! and it booted all the way to the desktop. I was ecstatic it was fully functional. i ran open mark and it completed with no issues scoring exactly the same as a real X850XT mac edition so now I have an effective X850XT that works in G4s as well as G5s Woo!
as you can see it fully detects my monitor and it has none of the issues that a reduced Non retail card ROM would have.
I am very proud of this as this is the first SMD soldering I have ever done (apart from a reflowing a MacBook Pro in an oven
)
I hope you found this interesting and that it can help others wanting to try the same thing (but do note im not writing this explicitly as a guide more just a write up on how it went for me and what I did)
