Can we have RPN back?

[RyanB]

No argument here, but at least its an improvement over the placing on the 50.

-Ryan

[Matt Agajanian]

My turn.

As an old-timer, I vote for our traditional 4-level RPN (Woodstock and following) implemtation, with the additional HP-45 RCL +-x/ functionality for several reasons:

1--it was functional, versatile and poweful enough to merit usage of an HP-65 on the Soyuz mission

2--As per the 1982 HP calendar, several others 4-level RPN HP calcs were utilised in events such as America's Cup Yacht Race among other events.

3--A cadre of HP-41s were on board Sally Ride's missions.

4-The over 30 HP-67/97 and over 30 HP-41 Application Pacs in various disciplines from Mechanical Engineering to Biomedicine to Civil Engineering to Statistics and so forth.

5--Even now, with both the HP-12C and 35S, it stands to reason 4-level
RPN is still robust, versatile and efficient.

6--Extended functionality of RPN is enhanced when applications and stack manipulations from John A Ball's 'Algorithms For RPN Calculators' and the TK Enterprises book 'Everything You've Always Wanted to Know About RPN' are put into practice.

[Joe Horn]

(03-30-2014 04:42 PM)HP67 Wrote:  The ENTER key should be midway up on the left side of the keyboard.

I disagree, and here's why. On Prime, press and hold down Enter with your right hand. You can still see all the digit keys; your hand is not in the way. Now (also using your right hand) press and hold down ENTER on any other big-ENTER-key HP calculator. You can't see several digit keys, because your hand is in the way.

So having the ENTER key on the left side always seemed to me to be a design mistake for right-handed people, since you can't see what you're going to press next while pressing ENTER. This slows down the user. Ditto for the arithmetic keys; it's nice to be able to see the next number's keys while performing arithmetic. Prime has all 5 keys on the right, which (as explained above) is the most efficient side for right-handed people.

Disclaimer: The above is not a religious declaration of absolute truth. It's true for me, but everybody's different, thank goodness. It's definitely not true for southpaws. It's also not true for people who hold their HP with both hands and press the keys with their thumbs.

[Han]

(03-31-2014 03:37 AM)Joe Horn Wrote:  I disagree, and here's why. On Prime, press and hold down Enter with your right hand. You can still see all the digit keys; your hand is not in the way. Now (also using your right hand) press and hold down ENTER on any other big-ENTER-key HP calculator. You can't see several digit keys, because your hand is in the way.

So having the ENTER key on the left side always seemed to me to be a design mistake for right-handed people, since you can't see what you're going to press next while pressing ENTER. This slows down the user. Ditto for the arithmetic keys; it's nice to be able to see the next number's keys while performing arithmetic. Prime has all 5 keys on the right, which (as explained above) is the most efficient side for right-handed people.

You make a very valid point. That said, my first HP calculator was an HP 48, with its ENTER key on the left. I learned to use my calculator with two hands (typing with both thumbs!) and this enabled me to alternate buttons very quickly. This was due to having played many video games on the GAMEBOY, so I was very used to holding the calculator with two hands and using my thumbs to alternately type. So while ENTER on the right may seem logical as all the other operations are also on the right, it would slow me down considerably. Imagine typing 2 SIN 4 * ENTER + -- with ENTER on the left, I can alternate between left and right thumbs to quickly access the last three operations, whereas it would be much slower for me to use just my right thumb to press * ENTER +. I see having ENTER on the left being as useful as having the keys on a PC keyboard laid out in non-alphabetical order.

[HP67]

(03-31-2014 03:37 AM)Joe Horn Wrote:  

(03-30-2014 04:42 PM)HP67 Wrote:  The ENTER key should be midway up on the left side of the keyboard.

I disagree, and here's why.

Oh, I was referring to the historical ENTER key placement but I used the word "should" instead of "has traditionally been."

(03-31-2014 03:37 AM)Joe Horn Wrote:  It's also not true for people who hold their HP with both hands and press the keys with their thumbs.

Yes, I'm pretty sure that's how I always used all my calculators. So having the ENTER key where it was in the old days was fine by me. Since it didn't get in my way, and was traditional, I prefer it now too. Any other placement seems odd and disruptive because of the history and habit, not for any ergonomic reason. That said, it would have been nice if all the models would have had roughly similar layouts.

[Thomas Radtke]

(03-31-2014 06:19 AM)HP67 Wrote:  Any other placement seems odd and disruptive because of the history and habit, not for any ergonomic reason.

But there is one. The binary operators should never be shadowed by the hand since at least with RPN, you have no other feedback than the result. This is different from the numerical keys, which are actually displayed. I always found old HPs easier to operate with the right hand while the new arrangement is excellent for us left-handed operators. And yes, the ENTER belongs above the binary operators.

[Tim Wessman]

Basically, the ENTER key placement reasoning went something like this in my mind.

1) There must be a large enter key.
2) The primary assumption we have about our users is that they are going to be more familiar with other keyboard layouts. Thus cues from software keyboards on phones and computers should be taken into account.
3) ENTER has long since standardized on *essentially* all keyboard being on the far right of the keyboard.

That would be enough to finalize it in my mind. There were plenty more reasons, and plenty of times we'd want "just one more key" for something that it was tempting at times to make it a standard width.

The same reason why the bksp/delete key uses a more universal symbol instead of test. Symbols were attempted to be used as much as possible on the keyboard to aid with making it much more international.

The ESC key should have gone on the left top corner. However, there was no way to do so without breaking up the application buttons which is so critical to the central operation of the calculator. Hence we decided that consideration overrode the "esc being in the top left" standard.


Keyboard layout is one of those very difficult things that completely is impacted by the way you operate the device. There are basically two large groups that are roughly split down the middle. Either you operate with two hands while holding the device, or you use one hand and press down on the calculator. If you are one vs the other, then the other ideal layout for that other group just doesn't make sense to you and seems very inefficient.

[Steve Simpkin]

Tim,
Thank you for that detailed information and all of the information you have been able to share with us. It really helps in understanding the development process for a product that is trying to meet many, sometimes conflicting, requirements and design goals. I am really happy that RPN and the big Enter key made it through the "minefield" of HP's development process. Thank you.
Steve

[Matt Agajanian]

Hi all.

It just came to me. If I were to have 4-level RPN back, the ideal structure of it would come straight from the HP-42S.

All data types automatically handeled, no 'Complex Mode' setting, etc. necessary.

All data types occupy a stack register. No need for a parallel stack for complex numbers (HP-15C).

At least, for me, that's an excellent start.

**In addition, as another member mentioned (perhaps from either an earlier post or different thread), as eight levels of stack entries is somewhat daunting to keep track of, perhaps a user-definable stack depth (with proper T-level pop operation for top of stack register) would be a better compromise.

[orcinus]

(03-29-2014 11:53 AM)John R. Graham Wrote:  Now, all that said, I think the RPL family implementation of RPN is more straightforward, and I'm quite used to it. However, if the old automatic lift functionality had been present as an option on the RPL family (enabled, say, by a flag), I might've enabled it. Who knows?

Hah, interesting. Never used a "classic" RPN machine before, been through all RPL models from 48 onwards.

Now i'm tempted to buy one from ebay or, heck, even buy a 35s, just to play with it and see how i like it.

Thing is, over time, i got used to using the stack as a scratchpad, i.e. i grew used to "multitasking" with it (multiple calculations, results left over from previous calculations and labeled, lots of rolls, dups, drops and picks, stores and recalls from vars). Which is why i can't seem to wrap my head around the RPN way of doing things