Hello all, I am an MPhil student at Cambridge in the HPS department working on our science museum’s calculator collection (the Francis Hookham Collection of Handheld Calculators) for a short essay. In working through the collection of calculators and associated ephemera, I have become very interested in HP’s programmable calculators, particularly the HP-65 and subsequent developments in which programs could be written stored on magnetic cards, sent to and ordered from a user library, and also purchased in packages from HP. Given the recent de-emphasis on computation as calculation, this is a fascinating instance in which calculation itself helped create a form of social organization; calculators were not about simply crunching numbers but sharing and writing programs. I was wondering if anyone on this list a) used these calculators and their magnetic cards or b) know of anyone who might be willing to discuss with me. I am trying to answer the following questions about the magnetic cards and these calculators: 1) How common were they to have? HPs were notoriously expensive and their being programmed in RPN may have led certain groups to turn to other companies like TI. I don’t know how much discussing RPN would figure into this account but I am interested in programming language entrenchment/preferences as well. 2) What was the incentive to enter programs into the HP user library? Was it financial? Did people code programs on spare cards and send them to each other? Was it enough to buy the various packs that HP marketed (Statistics, Flight, Medicine, etc.) or was this seen as facile/not trustworthy? 3) If you yourself worked with these HP calculators with magnetic card readers in the ‘70s and ‘80s, where were you working and to what extent was it desirable to shop for programs rather than simply writing them yourself? I am interested in how different calculators were used infrastructurally but also understand that it was often a source of personal satisfaction and intrigue, as can be seen in the case of Francis Hookham who collected so many calculators! Thanks so much for hearing me out and I hope to hear from some of you! Sincerely, Mikey McGovern