OK, here's the TwinTurbo 128 M8A version: Custom_TwinTurbo9600_Driver.sit
I included extensions pre-configured for 1680x1050 and 1920x1080, so for those resolutions, just drop the appropriate extension and restart, then select the resolution in Monitors. Currently I haven't figured out how to have it re-select this resolution each time you restart (it'll show it selected for me, but I have to switch to another resolution, then switch back, to get it to take effect after a restart). Let me know how this works on your TwinTurbo.
Here's the same for the built-in version, extensions pre-configured for 1680x1050 and 1920x1080 (no other changes to this): CustomGraphicsDriver.sit
I included extensions pre-configured for 1680x1050 and 1920x1080, so for those resolutions, just drop the appropriate extension and restart, then select the resolution in Monitors. Currently I haven't figured out how to have it re-select this resolution each time you restart (it'll show it selected for me, but I have to switch to another resolution, then switch back, to get it to take effect after a restart). Let me know how this works on your TwinTurbo.
Here's the same for the built-in version, extensions pre-configured for 1680x1050 and 1920x1080 (no other changes to this): CustomGraphicsDriver.sit