Now that you mention it, the HP-48GX is another calculator that found a niche: land surveying. It's so popular in that particular line of work that you can bare

Now that you mention it, the HP-48GX is another calculator that found a niche: land surveying. It's so popular in that particular line of work that you can barely get your hands on a used one on eBay. There are still third-party cards for COGO and data collection that surveyors and some civil engineering professionals rely on. I still have my HP-48GX from college along with the manual and it's a standard tool of the trade: http://www.johann-sandra.com/surveying/hp48gx-hp-48gx-48.htm http://www.johann-sandra.com/surveying/hp48gx-hp-48gx-48.htm