0x800-0x2000
Place some of the tick opcodes there. This gives enough room for all
but 2 of the op_tick_*_page_n opcodes!
It may be possible to fit the remaining ones into unused RAM in the
language card, but this will require some finesse to get the code in
there. Or maybe I can optimize enough bytes...
0x300 is used by the loader.system, but there is also still 0x400..0x800
if I don't mind messing up the text page, and 0x200 if I can
get away with using the keyboard buffer.
Something is broken with RESET now though, maybe the reset vector is
pointing somewhere orphaned.