HP 12c calculator: Still up-to-date after 30 years

HP releases a 30th anniversary edition of the HP 12c calculator that's the same as the original.

Dong Ngo SF Labs Manager, Editor / Reviews
CNET editor Dong Ngo has been involved with technology since 2000, starting with testing gadgets and writing code for CNET Labs' benchmarks. He now manages CNET San Francisco Labs, reviews 3D printers, networking/storage devices, and also writes about other topics from online security to new gadgets and how technology impacts the life of people around the world.
Dong Ngo
3 min read

The 30th anniversary edition of the HP 12c calculator.
The 30th anniversary edition of the HP 12c calculator is perfect as is. Dong Ngo/CNET

You probably change your computer every couple of years and update your phone based on Apple's release cycles. But chances are that inside your briefcase or in your desk drawer, there's a gadget that hasn't been changed for decades. It still works well, and you like it just the way it is.

The device in question is the HP 12c calculator, first launched exactly 30 years ago today, on September 1, 1981. Ever since, without much fanfare, it's been a quietly vital tool in finance, business, and academia. According to HP, the 12c is still one of only two standard calculators permitted for use during financial professional certification exams. This is because when it was released, the calculator offered more-accurate computations than the federal standard. It also features an unmatched keypad layout that provided unprecedented ease of use. The device itself is compact enough to fit in a pants pocket.

Dennis Harms, the Project Manger of the original HP 12c calculator.
Dennis Harms, the project manger of the original HP 12c calculator, reveals the secret of its success. Dong Ngo/CNET

During a chat with CNET, Dennis Harms, the project manager of the original HP 12c, revealed a few secrets of the HP 12c's success. First of all, it was the first calculator from HP to feature Reverse Polish Notation (RPN), which improves user input efficiency. For example, to get the total of 4 plus 6, you just have to type in "4 [enter] 6 [enter] +", instead of having to use the equal sign. This cuts down the time a user has to work on the keypad.

However, the design is one of the best parts, according to Harms, because it minimized the amount of components inside. Essentially, the calculator has only three main parts: the processor, the RAM ROM Display Driver chip (aka "R2D2") and a digital clock. This allows the product to last for years on just two miniature replaceable batteries. "The processor itself computes in decimal, instead of binary, making the calculation very accurate and fast at the time," Harms said. The HP 12c is also one of the first devices that uses CMOS for its circuit-board and 10-digit registers as its memory.

Harms believes the reason why the HP 12c is still in use today, despite the fact that all smartphones and personal computers include a calculator app, is because the device just works, and works instantly without loading time. According to Harms, the 12c is also an example of HP's emphasis on quality at that time. As he recalled, previous generations of HP calculators hadn't done so well and the upper management told him and his team to take their time to make the product as good as it could be. "They told us not to screw this up and that we're not going to introduce this thing until it's ready," Harms said.

Still, the success of the 12c has gone beyond the expectation of HP, which in the early '80s was still focused mostly on test and measurement devices. According to Harms, the product was first ordered by college bookstores. At the time, because of the common lag between ordering and production, retailers tended to order about four times the number of products they expected to sell immediately. The bookstores ordered 4 million units of the HP 12c, expecting to sell just 1 million. To everyone's surprise, everything sold out at launch.

The HP 12c was expected to last just a few years on the market. Thirty years later, the question is: when will it no longer work for our needs? According to Harms, because of the memory limit, the 12c's date calculator can handle dates only up to 11/16/4096. After that, it might not be reliable anymore. While this is not exactly year 5K-compliant, it looks like it'll be quite a long time before you'll need to replace it.

And if you don't have one yet, HP announced today that it's now shipping the 30th Anniversary Edition of the calculator. The product is basically the same as the original, except for a unique production number laser-etched on its back. Each 12c comes in a gift box and costs $79. The original HP 12c was priced at $100 when it was launched.