MC_REGB_24HR
mc146818_write(sc, MC_REGB, MC_REGB_BINARY | MC_REGB_24HR);
MC_REGB_PIE | MC_REGB_SQWE | MC_REGB_BINARY | MC_REGB_24HR);
mc146818_write(NULL, MC_REGB, MC_REGB_24HR | MC_REGB_PIE);
mc146818_write(NULL, MC_REGB, MC_REGB_24HR);
mc146818_write(NULL, MC_REGB, MC_REGB_24HR | MC_REGB_AIE);
mc146818_write(NULL, MC_REGB, MC_REGB_24HR);
mc146818_write(NULL, MC_REGB, MC_REGB_24HR | MC_REGB_PIE);
mc146818_write(NULL, MC_REGB, MC_REGB_24HR);
mc146818_write(sc, MC_REGB, MC_REGB_BINARY | MC_REGB_24HR);
rtc_write_reg(sc, MC_REGB, MC_REGB_BINARY | MC_REGB_24HR);
rtc.regs[MC_REGB] = MC_REGB_24HR;
if (!(data & MC_REGB_24HR))