Most mind-blowing program for your favorite calculator

[Steve Simpkin]

I don’t know if this qualifies but in retrospect it seems kind of far fetched by today’s standards.

I bought my HP-25 in 1977 and used it though high school, four years of college, and my first two years of work as an engineer. While I wrote many small programs to automate tasks, the most complex one was for a project at work around 1984.

I had to create a table of elevations and compass headings used to aim a portable 5 foot satellite dish at the Galaxy II geostationary television satellite from about 200 latitude/longitude locations across north America. I obtained the required formulas from a library book, wrote the program, entered it into my HP-25, plugged it into AC power and away I went. At the time I didn't have access to a computer with a printer. The "company" computer filled a LARGE room, used punch cards and no one, including the people who manned it, knew how to write new programs for it. The latitude/longitude locations were provided for selected cities in the U.S. that I would have had to enter manually anyway. The HP-25 did the job in a fraction of the time and effort any other method would have required.

You really could do a lot with 49 steps of program memory. HP product do "fill real needs, and provide lasting value".