# HP 10bii Calculator

This is a reproduction of the HP 10bii

Our design goal was to give users a clean 10bii that they could feel comfortable with immediately without the awkward additions found on other iOS implementations of this HP classic. Since CALC 1 contains so many tools for calculations, we did not need to add anything to the 10bii reproduction. We share the stack, TVM values and some storage registers so the user can switch between the 10bii and the many CALC 1 tools.

## The examples and instructions in the HP manual will apply to this reproduction with these differences / enhancements:

- The PEND indicator is not used since the parenthesis, math operators and right hand value are displayed.
- Text instead of graphics is used for the key labels to take advantage of iOS Dynamic Type. This allows the user to adjust the text size for this calculator. You can also adjust the buttontext size in the Styles options.
- An easy to read font was used instead of a 7 segment LED style font for legibility and Dynamic type. This also allows error messages instead of error codes.
- CALC 1 uses double precision floating point format for calculations for a maximum of 1e+308.
- The ON key from the hardware calculator is not needed so it is a BACK key on standard iPhones to exit the calculator. On plus size iPhones this is used to toggle between a full and compact view in landscape.

## How the 10bii fits in with CALC 1

### Shared values

- The stack (x, y, z and t values and last x)
- TVM values: N, i (rate), PV, PMT FV and BEG/END mode.
- Storage registers 0 to 9. CALC 1 uses variables a-z instead of numbered storage and the 10bii 0 to 9 storage registered are copied to the variables used with keys 0-9.

Sharing values allows you to use the 10bii to calculate a payment, then switch to the Amortization Form Calculator to generate a amortization table or graph without re-entering the values. This is just one example of the many tools available in CALC 1.

### Shared Options

- The calculation mode on the 10bii is the CHN (chain) mode on CALC 1. When you exit the 10bii, the calculation mode will be CHN in the CALC 1 options.
- The number of digits are shared. If set to more than 9 in CALC 1 it will be reduced to 9 in the 10bii.
- The CALC 1 “use significant digits” options is turned off for the 10bii.
**Key Clicks** can be set in the CALC 1 options.

See the CALC 1 Options page for more information on CALC 1 options.

This calculator uses the first formula in Time Value of Money Compound Interest Formulas.

For more information about what CALC 1 has to offer for 10bii users, see the CALC 1 User Guide for HP 10b Users.