Well after some thought, I am not certain that there would be a significant difference. I am not a computer scientist; with 1M you would be introducing microamps and with 1G you would be introducing nanoamps. I do not know whether that makes a difference in the amount of calculating (precision) needed. I guess that if the simulator really needs the resistor to be there, that means that it is assuming absolutely no coupling between AC and DC when the diodes are not forward conducting. So if that is the case, then 1 G ohm should probably work.
My experience with programmable calculators is limited to a few HP models using “Reverse Polish Notation”. I think that I got to use first an HP35 (not programmable) and then I think an HP55 which was programmable. Eventually I bought an HP21 (if I remember correctly)…that was programmable and during the 1980s an HP11C which I still have and use today. But with circuit simulators and Spreadsheet calculation, it has been decades since I last programmed a calculator… So I have not ever used a TI-84. I would not want to have to program my HP11C but I guess I could dig up the manual and struggle through it if I needed to do so.
If I remember correctly:
- I probably used a fixed Vf (such as 0.7 V) for the diodes. The error from this would not be significant unless the voltages involved are very low.
- With limited memory and program steps, I could calculate (something like) ripple valley voltage or RMS ripple current but not both in one “run”.
- The results agreed quite well with hardware tests.
BTW the other thing that I have done (alluded to above) in more recent years is spreadsheet simulations. During the 1990s my employer bought (I think it was HSpice?). For the life of me I could not get reasonable results with that. Whatever version of Spice that was, I think it was particularly user “unfriendly.”. But I could simulate a comparator oscillator using an Excel spreadsheet, and my results came out within 1% of the bench test results.