Posts: 4,027

Threads: 172

Joined: Aug 2005

Hello;

maybe I'm wrong, but it seems you wanted to address your post to Hewlett-Packard Company itself. In fact, this Museum and particularly this Forum are exclusively private initiative.

Anyway, about the formulas: I know the IRR and about all related financial formulas used in Hewlett-Packard calculators can be found at the HP12C's "Owner's Handbook and Programming Guide", Appendix D, titled "Formulas Used". This manual also refers to other specific publications in particular cases, like *Standard Securities Calculation Methods* as a reference for Bond calculations.

Hope it helps. But if you still need the formulas, feel free contacting me so I can send you more info.

Best regards.

Posts: 14

Threads: 2

Joined: Jan 1970

I do not know exactly what HP uses, but I have a functional set derived using the 28S algebraic equation solver, if you are interested.

E-mail me if you want me to send them.