BACKGROUND_COLOR_Z
gpx_viper_write(ss, VIPER_Z_LOAD | BACKGROUND_COLOR_Z, 0);
gpx_viper_write(ss, VIPER_Z_LOAD | BACKGROUND_COLOR_Z, bg);
gpx_viper_write(ss, VIPER_Z_LOAD | BACKGROUND_COLOR_Z, bg);
gpx_viper_write(ss, VIPER_Z_LOAD | BACKGROUND_COLOR_Z, 0);
gpx_viper_write(ss, VIPER_Z_LOAD | BACKGROUND_COLOR_Z, 0);
write_ID(adder, VIPER_Z_LOAD | BACKGROUND_COLOR_Z, 0);
write_ID(adder, VIPER_Z_LOAD | BACKGROUND_COLOR_Z, 0);
write_ID(adder, VIPER_Z_LOAD | BACKGROUND_COLOR_Z, 0);
write_ID(adder, VIPER_Z_LOAD | BACKGROUND_COLOR_Z, 0);