I don't understand the HP-50g, what am I missing?

[bxparks]

Hello,
One of my goals for 2024 was to learn RPL. I had never used a 28 series or a 48/49/50 series calculator before. I am familiar with RPN calculators only, having used or owned the 12C, 15C, 42S, and the 30b, and being somewhat familiar with other HP RPN calculators. I had read numerous people on this forum (and elsewhere) proclaim how they much love the HP-50g. So I bought myself a 50g as a Christmas present, and started reading the 887-page "User's Guide" PDF file.

It was rough. I kept pushing myself for about 250-300 pages, then gave up. I am convinced that I am missing some fundamental concepts about the 50g. I hope this forum can shed some light on some basic questions. I don't know anyone in person that I can ask.

1) What Do the Arrow Keys Actually Do?

The arrow keys on the 50g seem to perform secondary actions, but there are no labels next to those keys. I have looked all over the User's Guide (e.g. p 1-11 "Introducing the Calculator Keyboard"; Appendix B "The Calculator's Keyboard", etc) but I cannot find this information.

The LeftArrow sends me into some graphical "paint" mode with a + sign as the cursor. I don't know what this mode is.

The RightArrow is X<>Y, I discovered that by accident.

The UpArrow and DownArrow move the cursor up and down the RPL stack. But what can I do there in the stack? I can delete an entry with the <- button. I expected ENTER to copy and paste the entry at the cursor to the bottom of the stack, but ENTER does nothing. I tried 'RightShift COPY' and 'RightShift Paste', but that does nothing.

The LeftShift+UP and RightShift+UP *seem* to be PageUp. The LeftShift+DOWN and RightShift+DOWN *seem* to be PageDown, but not always. For example, RightShift+DOWN in a certain mode shows a list of words: EDIT, VIEW, STACK, RCL, PURGE, CLEAR. But I don't understand the purpose of this list. I cannot scroll those words with the arrow keys. As soon as I hit an arrow key, that list clears and I exit out of that mode.

RightShift+RIGHT goes into "Xmodem Server Waiting for command". Which seems like an odd mode to attach to a RightShift+RIGHT. Is the Xmodem Server used so often that it deserves this shortcut?

Is there a reference in the User's Guide that explains what the arrow keys do in all contexts?

2) Soft Menu Does Not Always Work

I have MODE > FLAGS > Flag 117 set to "Soft MENU", because I am familiar with the HP-42S user interface. But it seems like there are numerous bugs where a menu mode is rendered in "CHOOSE boxes", instead of "Soft MENU", for example:

• RightShift+STAT
• RightShift+TIME
• RightShift+NUM.SLV
• LeftShift+FINANCE
  

Is there a way to force these to be "Soft MENU"?

3) How to Exit to Parent Folder from Child Folder When Using Soft Menu

After clicking on a soft menu folder, is there a way to quickly go back up to the parent folder, like the ON/EXIT button on the HP-42S? On the 50g, the ON/CANCEL button will exit out of a 'CHOOSE box' menu. But when using Soft Menu, I have to press the NXT button (I had to Google that one) multiple times to get the last row, and usually there's a soft menu button back to the parent folder. But I have at least 3 problems with this:

• It's slow and error-prone, because I don't know how many times I have to hit NXT to get to the last row.
• I sometimes forget what my parent menu folder was called, because I'm not familiar with the 50g menu system, and I'm doing a lot of exploration.
• The soft menu going back to the parent folder goes to the wrong row in the parent sometimes. For example, the 'MTH > PROB' folder is in Row 2 of 'MTH'. When I click on the 'MTH > PROB > MTH' backlink inside the 'PROB' subfolder, it takes me back to 'MTH > Row 1'. Then I have to hit 'NXT' to get to Row 2 where the 'PROB' soft menu was.
  

Maybe it's because I'm not used to it, but I find the 50g menu system to be slow and frustrating compared to the 42S.

4) Where is the SHOW function?

There are times when a number on the stack is too long, so the 50g displays the first part of the number and ends with an ellipsis "...". How do I view the entire number? Where is the equivalent of the SHOW function that other HP calculators have?

The obvious key binding for SHOW to me is the RightArrow key, because of the ellipsis character. But the 50g doesn't do that. Which is how I discovered that RightArrow is actually X<>Y.

5) How do I Invoke the Equation Writer on a Previously Entered Equation?

One of the first examples of using the Equation Writer (RightShift+EQW) is on page 1-13, which has the following example, sqrt(3 * (5-1/(3*3))/(23^3) + e^2.5), which looks like this in MathJax/Latex mode:

\[
\sqrt{\frac{3\cdot(5 - \frac{1}{3 \cdot 3})}{23^3}+e^{2.5}}
\]

I have tried to enter this equation into EQW about 4-5 times over 3 months, and I have never been able to enter it correctly. I cannot seem to be able figure out how to use the arrow keys to get to the correct location to remove or add the correct parenthesis or term. (Amusingly, I was able to enter this expression correctly in RPN mode on the first try.)

So I enter the incorrect equation, and it shows up on the RPL stack, and I can see that it is wrong. How do I edit that equation?? I have tried everything:

• I scroll up to that term with the arrow keys, hit RightShift+EQW, and my expectation is that it should copy that back into the EquationWriter. Nope.
• I scroll up, hit RightShift+COPY, then go into RightShift+EQW, then hit RightShift+PASTE. Nothing
  

I have searched the User's Guide for information on how to edit a previously entered equation. It must be in there somewhere in the 887 pages, but I cannot find it.

6) Where is the MENU button??

Several places in the User's Guide refer to a MENU button:

• Page 3-21, "117.02 ENTER MENU" (something about UNITS)
• Page 6-26, "74 MENU" (the SOLVE menu)
• Page 18-15, "96 MENU" (the STAT menu)
• Page G-3, there are apparently a bunch of menus which are only accessible through cryptic numerical codes: "96 MENU", "81 MENU", "74 MENU".
  

I have examined every key on the 50g keyboard, with a magnifying glass. I cannot find a MENU button. Where is this thing??

Secondly, why are certain menus exposed only through numerical codes? There are maybe hundreds of menu rows on the 50g. How is it possible that these hidden menus could not be exposed through one of those existing menus? There is almost zero chance that I will be able to remember the numerical codes for these hidden menus, which means that they might as well not exist.

7) Two Slightly Different CMPLX Menus, Why?

Complex numbers are entered and displayed as a 2-element list. That's a bit weird, since the HP-42S and the 35s have already demonstrated more ergonomic ways of displaying them. But I think I can get used to that.

But I don't understand why there are 2 slightly different CMPLX menus: one accessed through 'LeftShift+MTH NXT CMPLX', and the second one through 'RightShift+CMPLX'. They are almost, but not quite, identical. Which seems almost insulting, because I am never going to remember the difference between the two.

8) Additional Thoughts

I have more questions, but I think I will stop here for now. As you can see, I have not made it to the RPL programming part.

When I took the 50g out of the box, it was in ALGebraic mode. So I wanted to put this into RPN mode. Easy enough, hit the MODE key, I see "Operating Mode..Algebraic", so I need to change this to "RPN". Then I hit a brick wall. The RightArrow is what I expected to pop up a dialog box, nope. ENTER was the other possibility, nope. Tried whole bunch of other buttons, nope. I had to use Google to learn that I have to press the 'CHOOS' soft menu button, the 2nd one from the left, buried along a bunch of other soft menu button. Not obvious to me.

Very few things about this calculator are intuitive. But I still want to learn RPL, so I hope to soldier on. My goal has been updated: Instead of 2024, I hope to learn RPL in 3-4 years.