A few weeks ago I’ve posted here some pics of my Altair 8800. What a blast. You may already know that when the Altair literally ignited the PC industry – PC as in Personal Computer – in 1975, there were already few small computer systems available on the market (built around the newly released Intel 8008 microprocessor – 1971). Such systems were the Canadian MCM/70 or the French R2E Micral (both released circa 1973). However, these systems were definitively not for personal use – despite the fact that their inventors are claiming that they are the fathers of the PC. Unfortunately, as the mainframes, these early systems were targeting industrial companies, governmental organizations or university research centers. What was really personal though in the ’70s, was the calculator. So I went back to my classic HPs and decided to showcase a few remarkable ones today. The 35 was the first scientific pocket calculator. A revolution commemorated a few years ago with the introduction of the HP-35s. The 65 was the first programmable pocket calculator. Yet another revolutionary piece of hardware. A real marvel of technology, and a real personal computer. Finally, the 67 – a solid improvement over the 65 – is my favorite among these classics.