Showing posts from July, 2021

HP 35 calculator 200 trick

In 1972 I bought the first HP 35 calculator sold on the Caltech campus.  It was not by far the first one on the campus – HP had distributed pre-release copies to numerous faculty members.  Max Delbrück, my next-door neighbor, had given me my first experience with the calculator one evening while hosting my landlady, her family, and me for dinner.  I was smitten. When the Caltech Bookstore posted the impending availability of the calculator I was the first on the list.  The arrival date was not known, so I haunted the bookstore. HP-35 (Source: They finally came in sometime in November of 1972, if I remember correctly, and I happily paid the $395 price (about a quarter of my life savings at the time).  It was everything I had dreamed of and more.  It transformed my Physics lab performance from C (great on execution and writeup, not so hot on accuracy of calculation) to A.  It made me popular as a member of study groups. Games with HP 35