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

[Eric Rechlin]

I think a big problem here is that the 50g really expects you to know the 48 series first, and there are a lot of assumptions that were made on it that are totally obvious to 48 users but completely perplexing to everyone else.

I'll quickly address each one of your questions:

Quote:1) What Do the Arrow Keys Actually Do?

This were labeled on the 48 so they made sense there, and their functions were retained on the 49/50 while the key labels were left entirely off the keyboard for space reasons. You just have to memorize them, unfortunately. It's kind of silly:

[Up Arrow]: Lets you interact with upper levels of the stack, labeled [STACK] on the 48 (honestly unnecessary because the [HIST] key does almost exactly the same thing)
[Left Arrow]: Goes to the graphing output (picture) display, labeled [PICTURE] on the 48
[Down Arrow]: Lets you view/edit level 1 of the stack in the best editor appropriate for it, labeled [VIEW] on the 48
[Right Arrow]: Does X exchange Y, or swap, labeled [SWAP] on the 48

Quote:2) Soft Menu Does Not Always Work

The 49/50 flag -117 tells the system whether to use the 48-style softkey menus, or automatically replace them with the 49/50 style choose-like boxes. Most of us prefer the former, but the latter were made default to help new users. However, back in the 48GX days, as an attempt to make that calculator easier to use, some of the softkey menus from the 48SX were replaced with new CHOOSE boxes for the 48GX. But at the time of the 48GX there was no option to go back (although in many cases the softkey menu was still available by hidden manual MENU calls). So this inconsistency was (IMHO) stupidly retained on the 49/50. I really think it should stick with softkey menus everywhere when flag -117 is changed, but the developers decided to retain the inconsistent 48GX functionality here.

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

This is another hidden feature on the 50. On the 48GX, you did this by pressing [MENU], which was the opposite shift of the [PREV] command, which then brought you to the PREVious MENU rather than the PREVious page. Note this was not the same as the MENU command on the 48. This was actually just an evolution of the more consistent 48SX, which has [PREV] in the same location as on the 48GX, but [MENU] was actually shown in the [LAST] grouping on a different key, meaning it was "Last Menu", which made a lot more sense. Again, an example of where the 48SX was a more coherent/consistent design than the 48GX, which in turn was a more coherent/consistent design than the 49/50 -- which gets even more obscure here. On the 49/50, you get to the previous menu by holding [Left Shift] and pressing [PREV], whereas you get to the previous page by pressing and releasing [Left Shift] and then pressing [PREV]. Yes, on a bunch of keys, holding the shift key when pressing the next key causes a different operation than pressing and releasing the shift key first. Yes, this is very very confusing for new users, but it allows a lot of extra useful shortcuts for users who know the "hidden" functionality.

Quote:4) Where is the SHOW function?

To view and edit, press [Down Arrow]. To just view (in tiny text that you can scroll around), press [TOOL] and then the |VIEW| softkey.

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

As above, press [Down Arrow] when it's on level 1 of the stack. When you are in the [HIST]/[Up Arrow] stack view mode, however, I can't remember how to invoke EQW on the selected item. There must be a way to do it but all the obvious (and slightly less obvious) ideas I have do not work. Maybe a deficiency there? Or maybe even I am baffled by the 50 and it's something obscure? Basically I'm looking for a way to invoke the EDITB command on it in the stack history view.

Quote:6) Where is the MENU button??

It doesn't exist. Amusingly, as said above the 48 does have a [MENU] button, but it doesn't actually invoke the MENU command, it just goes to the previous menu. But the MENU command is separate and must be typed in. It's not normally expected to be used, because it's really only for programmatically bringing up a menu that can be reached by other keys, or for bringing up hidden menus in the system that may have been on the 48SX or 48GX but are not normally used on the 49/50 (but remain accessible for backwards compatibility and power users).

Quote:7) Two Slightly Different CMPLX Menus, Why?

One is just the original 48 series CMPLX menu, for numeric values (reals). The other is the new 49 series CMPLX menu, for symbolic values (algebraics), using the CAS commands. This actually came from the Erable third-party program. When the 49 was made, lots of the CAS functionality was kind of just dropped in there from Erable rather than being done in a consistent manner. They attempted to fix that with the Prime by having entirely separate numeric and CAS modes, but I'm not convinced this was the right answer either. Basically you just have to remember different things are needed for numeric or CAS operations and have to keep in mind what is what -- and there is overlap between them too. With more time I think this could have been done better, but the 49 was rushed out in like a year of development, and once all that was set in stone it was never fixed even in the 7 years before the 50g came out. I think it's because it was very hard to decide the best way to do it, whether to have one set of menus for numeric and one set of menus for CAS, or tried to blend them together, or what. But what we ended up with was a [MTH] key that had all the historic 48 numeric commands under it, and then a bunch of other keys each with subsets of the 49's CAS-based symbolic commands. Not ideal but it's what we have. Really what it is is the 50 doesn't know whether it's trying to be a CAS engine, a graphing calculator, or a powerful programmable handheld, and we have a weird mix of everything with different prioritization in different places. Somehow it all just works -- but it's extremely unfriendly to beginners.

Quote:8) Additional Thoughts

That INFORM display behavior was inherited from the 48GX, and is possibly one reason why some users prefer the cryptic but consistent behavior of the 48SX instead. Another way to change the value is to press [+/-] to cycle though the choices -- again not obvious. The 50g really requires you to spend a long time studying and understanding its manuals (and really, the 48GX manual too, since the 50g User's Guide is not very good). The 50g was really designed to make sense for someone who used a 48GX before but as I said before, it can be totally baffling to just about anyone else.