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Trig Tangent Bug (3884 version WP-34S)
02-25-2016, 01:16 AM (This post was last modified: 02-28-2016 08:13 PM by BarryMead.)
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Trig Tangent Bug (3884 version WP-34S)
If you compile the 3884 version of the WP-34s firmware and flash a REAL CALCULATOR with this firmware, it will display the word "Reset", or "Restored", if you attempt to take the tangent of the value .9999999 (7-9's) (Angle in Degrees mode). The emulator does not have any problem, so the issue is probably related to a stack overflow/corruption. The reset error occurs weather in normal or Double Precision mode.

I confirmed that it was NOT battery related by attaching the USB cable to my calculator's (Harald Pott's USB board), which ensures that 3.1 volts is ALWAYS available to power the CPU irrespective of battery condition.

If anyone in the forum has an ICE debugger and can evaluate stack problems, perhaps we can see what is causing this crash, or why the tangent function only fails with certain input values.
I found several other input values that cause the tangent function to reset crash as well. (1.9999999), (1.00000001), (2.9999999), (2.000000001), (3.99999999), (4.99999999)...
It seems to occur with values close to but not exactly integer numbers (I hope this is a valuable clue).

Thanks, Barry
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Trig Tangent Bug (3884 version WP-34S) - BarryMead - 02-25-2016 01:16 AM



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