HP-65 & HP-67

[Dave Britten]

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.