Okay let's focus on getting a working system by an xorg.conf......
I'll use the xorg.0.log from the askubuntu page as a guide. I suspect you have something similar. The relevant snippet from the bottom is here:
There is no shame in not understanding this as first glance. The people trying to help on the askubuntu page literally answer 1000s of problems so they are not novices to linux. However, none of them properly read the log, instead, they all focused on the last error message "EE) Screen(s) found, but none have a usable configuration".
[ 1902.318] (**) R128(0): Using framebuffer device
[ 1902.318] (II) Loading sub module "fbdevhw"
[ 1902.318] (II) LoadModule: "fbdevhw"
[ 1902.319] (II) Loading /usr/lib/xorg/modules/libfbdevhw.so
[ 1902.325] (II) Module fbdevhw: vendor="X.Org Foundation"
[ 1902.325] compiled for 1.10.1, module version = 0.0.2
[ 1902.326] ABI class: X.Org Video Driver, version 10.0
[ 1902.326] (EE) Unable to find a valid framebuffer device
[ 1902.327] (EE) R128(0): Failed to open framebuffer device, consult warnings and/or errors above for possible reasons
(you may have to look at the server log to see warnings)
[ 1902.327] (II) UnloadModule: "r128"
[ 1902.327] (II) Unloading r128
[ 1902.327] (II) UnloadModule: "fbdevhw"
[ 1902.327] (II) Unloading fbdevhw
[ 1902.327] (EE) Screen(s) found, but none have a usable configuration.
Fatal server error:
[ 1902.332] no screens found
If you trace further back up you'll see there are other error messages, the first being "(EE) Unable to find a valid framebuffer device". It is trying to use a framebuffer device. We know this because it tells us "(**) R128(0): Using framebuffer device". This is in line with what the r128 manual says for PowerPC:
If we set this value to false in your xorg.conf it won't now look for a framebuffer and so you won't have the error.
Option "UseFBDev" "boolean"
Enable or disable use of an OS-specific framebuffer device
interface (which is not supported on all OSs). See fbdevhw
for further information. Default: on
for PowerPC, off
Now, what I am not sure about is the NoInt10. This is described in the "Screen" section of the manual, although it seems you can put it in the "Device" section too:
Whether you get another error relating to Int10 I can only speculate. A lot of people seem to set this to true so it is worth trying if you still have a problem.
Option "NoInt10" "boolean"
Disables the Int10 module, a module that uses the int10 call to
the BIOS of the graphics card to initialize it. Default: false.
The users 'axion' and 'walterav' are trying to fix the framebuffer error in a different way. I suspect there is a better way than they both describe, but let's cross that bridge after you at least get a working system.