TI 17bii solver: after you press the CALC key

[Don Shepherd]

For six months now, I have been running equations on both the 17bii and 17bii+ solvers. I have noticed two things. After you press the CALC key, the + model is much quicker than the original bii in creating the menus and letting you continue with the solve process. On the other hand, when you press the button to solve for a variable, the original bii is much faster at giving a result.

I would like to know what exactly happens after you press CALC, and why the older model is slower during that part, but much faster during the actual solving. I presume that, after CALC, the menus are generated and your code in syntax checked, but could it be that the original bii spent time optimizing the code whereas the newer model does not do that?

[Bill (Smithville, NJ)]

Hi Don,

I think you mentioned once that the 17BII+ seems to always make two passes when solving for a variable. I'm thinking that the first pass is to optimize the equation (rearrange terms, etc) and the second pass is to actually solve it.

While the original 17bii/19bii is probaly doing the optimizing only once when the calc key is pressed.

Just a guess.

You might want to look at memory usage. How does the memory usage compare between the two units before pressing CALC, after pressing CALC and after doing one solve.

Not sure if that would tell us anything, but worth looking at.

Bill