| Offset | Description |
| 0x00 | Current second (Real Time Clock) 1 |
| 0x01 | Alarm second1 |
| 0x02 | Current minute (Real Time Clock) 1 |
| 0x03 | Alarm minute1 |
| 0x04 | Current hour (Real Time Clock) 1 |
| 0x05 | Alarm hour1 |
| 0x06 | Current day of week (Real Time Clock) 1 |
| 0x07 | Current date of month (Real Time Clock) 1 |
| 0x08 | Current month (Real Time Clock) 1 |
| 0x09 | Current year (Real Time Clock) 1 |
| 0x0a | RTC Status Register A |
| 0x0b | RTC Status Register B |
| 0x0c | RTC Status Register C |
| 0x0d | RTC Status Register D |
| 0x0e | POST diagnostics status byte |
| 0x0f | Shutdown status byte |
| 0x10 | Diskette drive types |
| 0x11 | Reserved |
| 0x12 | Hard Disk drive types |
| 0x13 | Reserved |
| 0x14 | Equipment byte |
| 0x15 | Base memory (low byte) |
| 0x16 | Base memory (high byte) |
| 0x17 | Extended memory (low byte) |
| 0x18 | Extended memory (high byte) |
| 0x19-0x2d | Reserved |
| 0x2e | Check sum (low byte) |
| 0x2f | Check sum (high byte) |
| 0x30 | Extended memory above 1 Mb (low byte) |
| 0x31 | Extended memory above 1 Mb (high byte) |
| 0x32 | Current century1 |
| 0x33 | Information Flags |
| 0x34-0x3f | Reserved |