alarm A register
| SU | Second units in BCD format. |
| ST | Second tens in BCD format. |
| MSK1 | Alarm A seconds mask |
| MNU | Minute units in BCD format. |
| MNT | Minute tens in BCD format. |
| MSK2 | Alarm A minutes mask |
| HU | Hour units in BCD format. |
| HT | Hour tens in BCD format. |
| PM | AM/PM notation |
| MSK3 | Alarm A hours mask |
| DU | Date units or day in BCD format. |
| DT | Date tens in BCD format. |
| WDSEL | Week day selection |
| MSK4 | Alarm A date mask |