Thanks to the new programs (thanks Dave Britten) and related posts for both the HP-65 and HP-67, I have been using my 65 and 67 quite a bit in the last week. Both calculators are amazing but entering and debugging programs are WAY easier on the HP-67. Program line numbers, BST and GTO.nnn are incredible improvements. What a difference in only two years!

Dave

P.S.

I just noticed that my HP21 and HP-22 are in TI cases. Is that blasphemy?

I just got another pack of 40 blank program cards in the mail for my 65 (~120 ought to be enough, right???), so I hope to write many more useful and/or interesting programs for it. I may need a few more of these 40-card wallets, though.

I've got one to post that calculates any of the five variables for an IV infusion with linear ramp up/down periods. It's essentially an area-of-a-trapezoid problem with an equation relating total hours, ramp-up hours, ramp-down hours, plateau rate, and total volume. You can enter any 4 variables and solve for the 5th.

I think I also still need to post the markup/margin calculator I did... It relates price, cost, and markup/margin percent. You can enter any two and solve for the third, and also toggle between %-of-cost or %-of-price calculation modes.

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.

(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.