The Unisonic 811-C is an arithmetic calculator with algebraic logic. It has 6 functions, 19 keys, and an LED (light-emitting diode) display, typical of calculators of this era. The power source is 4xAAA.
Facts at a glance:
If you have a Unisonic 811-C that is no longer working, you can first try replacing the 4xAAA batteries. If that doesn't solve the problem, then you can consider replacing the calculator with a modern equivalent. We suggest the following current models as possible replacements: