HP 21

Hewlet-Packard
1975

Scientific Calculator

"Introduced on February 1 1975, just a month after the HP-55, this was the seventh handheld electronic calculator sold by HP, and the first to look different from the original HP-35 shape.The model number showed that it was to be the first of a new family - the "series 20" or "Woodstock" series. Its code name was "Pumpkin" - it was a small, non-programmable handheld calculator with lots of scientific functions. " Wlodek Mier-Jedrzejowicz.
Source: MoHPC - The Museum of HP Calculators

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