Buyers remorse of HP 48

[donovan1983]

(06-27-2020 02:53 PM)Dave Britten Wrote:  I find it very nice for programming scientific calculations, as it has a special variation of the input command ('?' on a Casio) which prompts you with the existing value of the variable, and you can simply hit EXE to reuse the current value. It's kind of like the INPUT command on a 32S or 42S. Very handy when you have a program that requires several inputs, and you want to run it a few times with slightly different values.

The 35s does this with its INPUT command. It displays the existing value of the variable and you can either change it or leave it alone before pressing R/S to continue.

If your program is just solving for a single variable in an equation, there's a way to make that more convenient to use. Here's an example program using the TVM equation:

Code:

LBL T
SF 11
0+P-F*((1+I)^(-N))-A*((((1+I)^N)-1)/(((1+I)^N)*I))=0
RTN

From the main screen, press FN= followed by T.

To use the program, on the main screen just press SOLVE followed by the variable you want to solve for. Similar to using the solver from the equation list, the solver will prompt for values for all the other variables and with each you can either enter in a new value followed by R/S or just press R/S to accept the existing value.

This was really helpful during my engineering economics course where the same few equations were used repeatedly.