The main loop will now have three input modes
CommandMode
DataMode - to direct Hex-file format input to the shadow memory
gameDataMode - to direct Hex-file format input to game memory
Port PD2 and PD3 used for Interrupts to count the Busy signals.
BusyFaultCount and ShadowFaultCount commands added to display the number
interrupts since the last Atmega1284 reboot.
BusyFault is counted when the live game RAM issues a busy to the Pinball 6802.
BusyFault would indicate a potential game crash.
ShadowFaultCount is recorded to get an idea how often the shadow memory might be
getting out of step with the game RAM.
The Shadow memory is updated with every read or write by the 6802.
The Shadow memory is not updated by a read or write to the game RAM from the memory port left side
Left side memory ports are for the ATMEGA 1284.
