The parent article tells the story starting from before the desktop calculator in question and devotes several paragraphs to it, and I didn't mean just that one web page. The parent article doesn't seem to have any information that isn't presented on hp9825.com.
The several paragraphs in the parent article corresponding to specifically that web page start at:
> Tom Osborne, a Berkeley-trained electrical engineer, wasn’t one of those 9000 employees. In his Bay-area apartment, he had built a floating-point electronic calculator he called the Green Machine (after the color of the automotive touch-up paint he used on the balsa wood case). He tried shopping it around but no one was interested until he showed it to HP in June, 1965.