Really a desktop computer, the 9100A combined Reverse Polish Notation (RPN) - a system for representing mathematical expressions without the use of parentheses - with a special algorithm that could
handle trigonometric and logarithmic functions. HP sold the 9100A as a calculator because at the time the perception was that a computer had to be big to be credible. Bill Hewlett said
"If we had called it a computer, it would have been rejected by our customers' computer gurus because it didn't look like an IBM. We, therefore, decided to call it a calculator and all such nonsense disappeared."
The 9100A is now recognized throughout the industry as the first desktop computer. In December 2000, Wired Magazine named it the first personal computer.
- Read an article about the 9100A originally published on HPNOW, an internal HP web site.
- See an original ad for the 9100A that appeared in Science magazine. (PDF, 1.27MB)
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