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
FV
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.