* put TABLES in the low memory, before the bank switch window
* reserve bank switch window
* put rest of the code after that and before the framebuffer
so TABLES lives just before $4000
and MAIN lives in $8000-$bfff
could split some more code and/or data into low mem
and/or move the tables not used in extended memory mode into
the bank switch window so they take no address space on XE
or expanded memory machines
This is a first step toward moving the UI to C and
adding file and network I/O in C. The fractal core
will remain in assembler as well as the multiplier.