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HP-15C LE (Limted Edition) Bug Reports

Posted by Katie Wasserman on 16 Sept 2011, 11:22 a.m.

This is a working list of bug reports on the newly released HP-15C LE with firmware dated 2011-04-15.

1) PSE run more than once in a program blanks display and run just once causes display flashing issues with SF 9. For example:

SF 9

2) When Cx,y/Px,y are run in a program multiple times with certain values (e.g., 8 ,3) it causes display flashing issues.

for example


3) Executing the self tests documented in the manual can corrupt program memory. In addition to the manual, Error 9 is cited on the back plate of the calculator. Perhaps the most expedient solution would be to make the self tests work on the calculator as they do on the 12C+.

4) Current draw is over 20ma when holding down a key, leading to rapid battery depletion. While not a bug this is fixable in firmware and does not happen on the 12C+.

5) The low battery indicator does not appear to work. Further, when the battery voltage gets low enough or the batteries can't supply enough current memory is lost, the calculator will not shut down gracefully.

6) The ON+g+ENTER self test menu has 3 options the first of which turns on all the display segments. If you next press the roll-down key it will turn off half of them. Press it again to turn on the other half. The next press will turn them all back on again. This is all documented.

What's undocumented is what happens if you press and hold the roll-down key. On the 12C+ the display will rapidly cycle through the 3 displays a couple of times then terminate the self test showing the X register. On the 15C LE it will do the same then show the current program line. When you release the roll-down key it will run the program starting at that point.

and from Jeff O. we have:

7) In complex mode, press f - (i) to temporarily display the imaginary component. While the temporary display is up, press a single digit key, as if you were starting to key in a number. As soon as the temporary display of the imaginary component goes away, the digit you pressed will be displayed, and the display will be flashing. Pressing another digit key will continue entry of a multi-digit number beginning with the one that was already entered, and stop the flashing display. Pressing any function key will execute the function on the flashing number and stop the flashing display. If you press more than one digit key while the temporary display is up, the flashing will not occur. On my 15C Classic, key presses during the temporary display are simply ignored.

8) In any mode, press f - PREFIX to temporarily display the full mantissa. While the temporary display is up, press a single digit key, and you will get the same behavior as above.

9) In any mode, press g - MEM to temporarily display the memory allocation. While the temporary display is up, press a single digit key, and you will get the same behavior as above.

10) I tried to think of other temporary display modes which might exhibit the above behavior and could not think of any. You can of course execute PSE from the keyboard which is a temporary mode of sorts. On the 15C Classic, keyboard input during the pause is ignored. On the 15c LE, input will be accepted as in the above examples and displayed after the Pause ends, but the display does not flash.

I point out the above to hopefully aid in producing a new bug-free ROM by documenting all inconsistencies found with the current one.

Edited: 26 Dec 2011, 5:23 a.m.


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