The Unimark 280 is an arithmetic calculator with 8 digits precision and algebraic logic. It has 7 functions, 23 keys, and one of the early LCD (liquid crystal) displays which incorporated a yellow filter. The power source is 4x1.35V cell.
Facts at a glance:
|Power Source||4x1.35V cell|
If you have a Unimark 280 that is no longer working, you can first try replacing the 4x1.35V 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 models as possible replacements: