| Key | Function description |
| A | Display time/date for 5 minutes |
| C | Switch to serial console |
| E | System info. Firmware version, battery voltage, current frequency, etc. |
| F | Change LCD contrast.1) |
| BIN | Reset LCD contrast to default values. |
| STO | Adjust RTC: decrement -1h |
| RCL | Adjust RTC: increment +1h |
| 7 | Cycle through available fonts |
| 9 | Configure CPU speed. Toggle between 12MHz and 48MHz |
| ÷ | Keyboard self test |
| ⨯ | Self test |
| − | Power reset |
| + | Endless test |
| . | Toggle decimal delimiter |
| GSB | Time/date adjustment.2) |
| GTO | Toggle annunciator position |