Inconsistent results #1: 12c vs. 12c Platinum


Ok gang. Found an inconsistent result. I was solving the first accuracy problem presented in the FIN (FI Improved) article from PPC Journal Jan/Feb 1983 Page 22f.

Here it is:

40 ENTER 26 x n
1.15 ENTER 26 1/x y^x 1 - 100 x i
0 PV
650 ENTER 26 / PMT

Both calculators return the same result (which is inaccurate, by the way) of -1,237,786.903 ("correct" answer is -1,244,458.491). The original 12c finishes about 1 second faster than the 12c platinum.

(And, another by the way...the 12c platinum switches to showing "running" in the display when it solves the Y^X...somehow, I think that makes it seem slower than simply "blanking" the display would be).

Now the example suggests resolving for the interest rate. With the FV in the display, I pressed STO i, which placed the FV into the i register. (Why? Who cares!).

When I press i again, it should solve for the interest rate.

The original 12c does this in a few seconds.

The 12c platinum shows ERROR 5 in the display.

This should not happen.


I would not have believed they would do this...

The only way you do this is to update the firmware of the old 12c, so the one you sell NOW is the same result as the more accurate 12cP.

Then you explain it away by saying that all calculators have been getting more accurate through the years-- and the consumer shouldn't be sticking with an old calculator... or buying used ones off eBay...

Gene, how old is your 12c "regular" model? Anyone got a brand new chinese thingy? Someone want to check old 12c with new 12c?


Good old one.


Hi, guys;

I tried the three problems in other calculators (19BII and 48G TVM SOLVER) so we have other "opinions". Check them out, please.

Luiz C. Vieira - Brazil

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