It will work with the 168 if the output resolution is lowered. to do this open up the library and change the video_timing.h file like so:
_RESOLUTION_VERTICAL 96
to
_RESOLUTION_VERTICAL 54
the basic formula is this:
16*_RESOLUTION_VERTICAL must be less than the amount of SRAM the board has. in this case with a vres of 54 the library will use 864bytes of ram(not much left for user code).
the horizonal resolution currently cannont change without modifying the render_line() function in video_gen.cpp. for instance to render a horizonal resolution of 120 change:
video_timing.h:
#define _RESOLUTION_HORIZONTAL 128
to
#define _RESOLUTION_HORIZONTAL 120
video_gen.cpp:
in render_line() remove the last set of the byte output code(these lines, note the comments):
"LD tmp_reg,X+\n\t" //16
"byteshift\n"
I do plan to implement a tile render engine at some point. so the memory needs of that version will drop drastically.
doing either of these changes will break the demo code. it modifies the whole screen space as it is now, and since the library assumes that you know what you are doing when changing the screen it does not do any bounds checking. I think I will add that to the next release.
I haven't tested any of the changes i suggested so....