HP-65 & HP-67

[David Hayden]

(01-17-2020 06:17 PM)Dave Britten Wrote:  I'm really impressed with how much can be done with just 100 partially-merged steps, and 5 subroutine labels! It's wild to think how this little handheld calculator jump started the "I don't have to wait 24 hours to get results back from the computing center" revolution.

I recently came across this in the HP-25 Applications Programs. It's from the description of the "sight reduction table" program on page 70:

Quote:This program calculates the computed altitude Hc and azimuth Zn of a celestial body given the observer's latitude L and the local hour angle LHA and declination d of the body. It thus becomes a replacement for the nine volumes of HO 214.

(emphasis added)

A little digging shows that H.O. 214 is "Tables of Computed Altitude and Azimuth" published in 1940.

Just imagine being a navigator with a bookshelf full of these volumes and discovering that for $195 you could get a hand-held machine that could replace them! It must have been truly revolutionary.