Murray wrote a lengthy blog post on the topic and put together a battery of TVM tests designed to stretch the TVM solver and found to his, and others, surprise, that not all HP-12C units were equal.

Former Goldman Sachs CEO Lloyd Blankfein sparked some tech nostalgia with a photo of a calculator made by HP Inc HPQ four decades ago. What Happened: “The battery just ran out on my HP12C. Never ...

Happy 25th Anniversary, HP-12C Calculator. By Mark J. Perry. AEIdeas. October 26, 2006. ... would have long battery life and would meet the HP “drop test” ...

Pictured above is the HP 12C Financial Programmable Calculator, available from the Hewlett-Packard website for $69.99.What makes this calculator totally unique among all consumer electronic ...

The HP-12C calculator, on the other hand, ... The battery life is legendary. HP used silver oxide batteries in the 1980s, before they were restricted to US military use only ...

Designed for dealmakers, the 12c is engineered to handle complex formulas for calculating loan payments, determining bond yields, and constructing depreciation schedules.

Behold: The HP 12c Financial Calculator 30th Anniversary Edition. Above you see the 30-year old original (left) and the new version, side by side.