Inspired by Gene's findings in his post "HP33S question:POLL - Try this in algebraic mode", I found a few more strange results on my S/N: CNA4100... 33S.

** WARNING ** The following key sequences involve CLEARING your 33S's memory. Only those who DON'T CARE IF THEY LOSE THEIR CALCULATOR'S CONTENTS should try these steps **

1. Switch to algebraic mode, and make sure the stack/display is clear by pressing the <C> (ON) key.

2. Using Gene's number, press: 24 then press the Minus key.

3. Your display should have "24-" in the top line and "24.00" (assuming FIX 2) in the bottom line.

4. Now clear the calulator's memory by pressing the green <leftshift> key, followed by the <clx> key (you know, the <backspace> key just below TAN). Using the big "wobble" key, navigate to: 3ALL, and press <ENTER>. At the "CLR ALL? Y N" prompt, navigate to "Y" and press <ENTER>

5. Finally, press: 24 then press the ADD key. What do you see? On my calculator, the top line is "-24+" and the bottom line is "-24.00". What's up with that?!?

Here's another one:

1. Do step 1 above.

2. Using Gene's number, press: 24 then press the Divide key.

3. Your display should have "24/" (/ is the divide symbol) in the top line and "24.00" (assuming FIX 2) in the bottom line.

4. Do step 4 above.

5. Finally, press: 24 then press the Divide key (or the Multiply or Minus or Plus key). What do you see? On my calculator, the top line is "0/" and the bottom line is "0.00". BTW, if you had pressed the any of the other keys (Multiply, Minus, or Plus), the top line would be "0x", "0-", or "0+", respectively, and the bottom line is "0.00").

I know these are really, really obscure key sequences, but aren't these bugs? I wonder if the original Walmart units are the same/different?

Matt