Category: HP

Hewlett-Packard or HP calculators only

HP-28S Battery Compartment Door

Battery Door from right

HP-28S Battery Compartment Door The redesign of the whole HP-28S scientific calculator case is quite difficult and very time consuming. In most cases the only thing broken is the HP-28S battery compartment door, so I decided my first step was to get that re-designed. Print testing phase of battery door The 3D-print of the HP-28S …

Continue reading

Permanent link to this article: https://www.teawea.com/hp-28s-battery-compartment-door/

HP Program Mortgage calculator

Mortgage program for HP28S

HP Program Mortgage calculator Formula The HP program mortgage calculator uses the following formula to calculate the mortgage payments:Payment = Price / [(1/I) – 1/{I*(1+I)^n}]I = Interest per month = yearly Interest / 12n = number of month Before you start, create a directory First make sure you are at HOME or root directory. You …

Continue reading

Permanent link to this article: https://www.teawea.com/hp-program-mortgage-calculator/

HP Program Pascals Triangle

HP program for pascal's triangle printout

HP program for Pascals Triangle Just recently I had to help my daughter with some algebra homework and I remembered the Pascal’s Triangle in order to calculate the binomial coefficients. I wanted to write a small HP program on my HP28S to come up with a fast solution. I am not explaining the program at …

Continue reading

Permanent link to this article: https://www.teawea.com/hp-program-pascals-triangle/

Load more