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Something terrible happened to me. MY HP 17B was low on battery. I disposed of the old batteries and replaced with new. When I turned on my calculator all of my formulas were lost! I am reaching out to this forum in hopes of regaining, essentially, my life. I am in the financing business and with out my calculator and these formulas I am useless.

The 1st one was pretty basic (not basic enough for me to come up with):

(1)Cost of collateral to be financed 'CST'
(2)My cost of funds 'INT'
(3)Length of term 'TERM' in months
(4)Amount of advance rentals 'ADV'
(5)commission % 'PTS'
(6)Residual Value (a 10% PUT would have a value of -10. A $1.00 buy out would leave the category blank / $0.00) 'RV%'
(7)Monthly debt service / payment 'PMT'

That's the easy one folks. I also lost formulas for quarterly billings in advance, deferred payments, step ups and step downs. Beggars can't be choosers. Any help would be amazing.

Do you have John Tirone's book? I bought it years ago and have no real use for it, I'd be happy to give it to you, if it has what you need.

I'm not sure whether this is the one you're looking for. Anyway, you might want to take a look at this old thread:


Care has to be taken in order to avoid shortening the battery terminals when replacing cells:


Hope this helps.

Do you remember where these formulas came from? HP published several "step-by-step solution" booklets for the 17b calculator that may have been your source for some or all of these formulas. PDF's of four of these booklets are available on the DVD set produced and sold by the host of this site.

Edited: 8 May 2013, 3:58 a.m.

Don, I would love the book. Gosh, thank you so much. My e-mail address is david@1stindependentleasing.com. Please e-mail me there and I will send you my physical street address. I, of course, will pay for shipping.

Hello Gerson,

That's it. That's what I am looking for in its simplest form. Now how to get the other formulas..?? The book Don is sending me will hopefully help otherwise I will hit up the forum with more detail.

Thank you!