I am celebrating today 30 years since I bought my first HP calculator -- an HP-55. I was in an engineering college and my parents showed me in 1974 an ad for the HP-65 -- the first personal computer. I had to have one. Because of the cost my parents gave it much thought. In August 75 I flew to Europe to join them for the rest of summer. As we drove from the airport I was handed several flyers for HP calculators-- HP-21, HP-25, HP-45, HP-55, and HP-65. I started studying the flyers for the 25, 55, and 65. I spent the next few days reading every word and going over the features of each calculator again and again. Finally I decided on the HP-55. It had built-in linear regression and basic stats, 20 registers, unit convertions -- all special features that meant a lot for me. I decided on that model and my family purchased it for me on August 22. I was not fulyl aware that the HP-55 had the least programming space and features (no subroutine like with the HP-65). I used the HP-55 for the next 2 years and pushed the machine to the limit of programming. In 1977 I bought an HP-67 and enjoyed the superior programming features (more steps and three levels of subroutines).
Today I took out my HP-55 (one I got recebtly from eBay) and played with it a bit. I wrote a few programs and keyed in others from the Math and Stat application booklet. This was the first step in a world of computers that because accessible to us.
Those were the days when HP was the calculator ACE!
Happy Programming!
Namir