Fans of Hewlett-Packard calculators say "it all adds up"

To a dedicated cadre of engineers and scientists, "H-P 35" is no mystery phrase. The Hewlett-Packard Model 35 calculator, introduced in the early 1970s, is to these people one of the great technological inventions of the 20th century It was also the precursor of a long line of machines that demonstrated a perfect marriage of form and function-aided by impeccable timing-to occupy a unique and critical rung in the history of computation. Although calculators found for themselves a perfect niche in the past 30 years, their role is bound to change. The article briefly considers their future