extern inline bool door_open() { return switch_input & A1800_DOOR_OPEN; }
extern inline void spi_enable() { bset((void*)&_io_ports[M6811_SPCR], M6811_SPE); }
extern inline void spi_disable() { bclr((void*)&_io_ports[M6811_SPCR], M6811_SPE); }
extern inline bool door_open() { return switch_input & A1800_DOOR_OPEN; }
extern inline void spi_enable() { bset((void*)&_io_ports[M6811_SPCR], M6811_SPE); }
extern inline void spi_disable() { bclr((void*)&_io_ports[M6811_SPCR], M6811_SPE); }