High Voltage C Maze

This is a direct translation of a Dr. Dobbs Journal raycasting demo.

It runs entirely on the GPU. The 68000 is stopped while this demo

is running. (If you stop the stub in the debugger and trace over a

few 68000 instructions, you'll notice the GPU wakes up and runs the

demo even though the 68000 is still running the debugger stub).

The changes that were made from the Dr. Dobbs version are:

- Reading graphics from ROM instead of from files

- Using blitter to copy pixels instead of CPU

- Adding work-around to fix compiler comparison bug