# Hewlett-Packard HP 11C (Voyager 1.0)

The Hewlett-Packard HP 11C is a programmable calculator with 10 digits precision and RPN (reverse polish notation) logic. It has 107 functions, 39 keys, and an LCD (liquid crystal) display. The power source is 3x1.5V cell.

## Facts at a glance:

Feature | Value |
---|---|

Type | Programmable |

Functions | 107 |

Keys | 39 |

Precision | 10 |

Logic | RPN |

Display type | LCD |

Length | 128mm |

Width | 79mm |

Thickness | 15mm |

Weight | 110g |

Power Source | 3x1.5V cell |

Year introduced | 1981 |

Year discontinued | 1989 |

## Diagnostics

Note that diagnostic tests generally delete any data on the calculator. Be sure to back up any important information held in the calculator before running these tests.

Turn calculator off, press and hold X (multiply) key and then press ON key, then release X key. Display will show "running" for about 20 seconds, and if tests pass, all display elements will be on. Press any key to exit test. For keypad test, use divide key instead of X key, and then press each key in turn (will show "Error 9" if out of sequence).

## Replacements:

If you have a Hewlett-Packard HP 11C that is no longer working, you can first try replacing the 3x1.5V cell batteries. If that doesn't solve the problem, then you can consider replacing the calculator with a modern equivalent. We suggest the following current model as a replacement: