@Amethyst1
when you tried to boot 10.1.5 on your 12 inch PowerBook, did it hang on a black screen with a corrupted curser?
I managed to nab myself a 1Ghz 17 inch PowerBook5,1 a while back, and I have finally put together a nice portable USB/FW SSD with all Major PPC OS X versions on it (which replaced my setup the same, desktop Lacie drive who's PSU died a while back)
and of course I know that the 17 inch AlBook and 12 inch 867Mhz PBG4 are architecturally very similar, so I figured if I can use my AlBook to figure things out for the both of us, and so I just wanted to check that we are on the same page
and as above thats where my PowerBook5,1 hangs which sounds similar to what your 12 inch PowerBook6,1 did