wp34s: the strict rpn sorta bugs me

[eri]

RPN and RPL are used pretty strictly on this forum - makes me realize I don't know what they mean - so I'm going to avoid those terms.

I'm sure this has been discussed but I can't find it.

I find the HP48, HP50 style input to be more natural than what appears to be the strict old-skool input that's honored by the wp34s. Wondering why wp34s couldn't have a mode to adopt the later input style. It seems like a very graceful superset of the older behavior.

Example (stuff typed into device is in quotes):

On hp48 I can type:
"1<enter>2<enter>+"
and result is 3 because the second <enter> just copies the edit register to x and no copy is implied. The "+" adds x and y. Only if edit register is empty does enter copy x to y.

On hp48 I can also type:
"1<enter>2+"
And result is still 3 because the "+" flushes edit register to x before operating.

On wp34s, if I think I'll be entering another number, then change my mind after hitting <enter> then I need to <r-down> the copy away. I'm finding it tough to break the habit of hitting enter after each entry.

Also, what is wrong with having <- cause the stack to be popped?

Doesn't seem like much of a stretch for the same behavior to be weaseled onto the wp34s but maybe I'm missing something.

Why does the wp34s stick with this old behavior?

How do you folks feel about the difference?

[walter b]

I admit I'm biased so I won't answer that (but you may find an answer on p. 22 of the printed manual).

d:-)

[Massimo Gnerucci]

<humour>

The short answer is: we are old people and we do not want to change a bit!



</humour>

[Thomas Radtke]

Since it is a RPN calculator, the user must be sure the calculator works as expected from one. Otherwise it would be something new like the 'mixed-mode' 20b/30b calculators, which falsely claim to have an RPN mode. Quite nasty since only the x-register is visible.

Strictness protects the value of your knowledge, a key factor anywhere in industry. And it's not a bad idea to keep techniques proven over decades.

[Massimo Gnerucci]

Thomas' answer was the long version.

And I completely agree with him, BTW.

[eri]

I don't see what is nasty about an edit register on a machine with a single line display. Do you have an example in mind?

"Strictness"... "decades": RPL has been around for decades too...

I guess this behavior change is just the first step on the path to RPL-land - because why stop at a stack with only 8 elements? And after we have a memory limited stack I'm going to complain about lacking objects: units and symbolic math.

Maybe we keep strict RPN so we have a well-bounded garden.

[Massimo Gnerucci]

Do you like RPL?
Fine, nothing wrong with that.

But, since HP doesn't market a pure RPN calculator since many years now, while you can readily buy a scientific or business RPN in RPL-style (and several RPL calcs) from HP... why shouldn't we have a classic RPN calc too?

[eri]

RPN style calc: I don't mind that wp34s supports traditional rpn mode. Hats off to those that prefer it.

I'm suggesting that the RPL syntax could be supported with a mode setting, for the folks that like it that way. Programs could save and restore the current "rpn mode" so both types could run on the same device.

I'm really impressed with what a natural improvement the rpl style is from strict rpn and not something I really noticed until I didn't have it. Elegant language thinking there on someone's part.

[Massimo Gnerucci]

Ok, that's fair. We too would have liked an RPN mode setting on calculators from HP-28C on...



Just my personal view on this matter, of course.

I like the power inside 28/48/49/50 series, just not usually needed for my everyday use (the days I use a calc...).

All the best!

[Howard Owen]

(12-19-2013 07:09 PM)eri Wrote:  I'm suggesting that the RPL syntax could be supported with a mode setting, for the folks that like it that way.

I'm pretty sure they are completely out of ROM to implement something like that, even if they cared to.

What's the problem with an enthusiast calculator aimed at fans of the last great RPN calculator from HP, the HP42s? This is supposed to be the calculator that HP would have eventually produced if they hadn't taken a hard turn into RPL. Regardless of how you feel about RPN vs RPL, the WP 34s is the best example of what an RPN calculator can be.

[Jim Horn]

Why strict RPN? As mentioned, many are used to it and like it. The WP 34S was specifically created to be an RPN machine. And, being open, anyone who really wants to can modify the code and make any changes they want.

Why prefer RPN? For a single line display which is also the X register / bottom of the stack, it is a simple and intuitive scheme. The somewhat byzantine stack lift rules for ENTER and such soon become second nature to most users.

RPL is a great advance that came along with later generation hardware including many line full graphic and alphanumeric displays, massive increases in RAM and ROM, etc. along with fantastically more capable system firmware allowing all sorts of data types.

I think of the difference by analogy: RPN is somewhat like a pocket knife; RPL is more like a bandsaw; Mathematical / Maple / etc. are like four axis computer controlled milling machines. Each has its advantages and place of use. I'm not without my knife - it's too useful in so many circumstances. And my WP 34S as well as Free42 on my Android phone are as well.

Best to you in your use of these terrific tools!

[eri]

Yeah really. Not exactly complaining about this fantastic tool. Using it every day. Love it. $15. I sure would pay more for better keys though.

Thanks Jim for the response.

I guess best reason to bring this suggestion up is so it can be considered for the 43, so long as rpl doesn't Poison the well.

[Thomas Radtke]

(12-19-2013 05:16 PM)eri Wrote:  I don't see what is nasty about an edit register on a machine with a single line display. Do you have an example in mind?

You already came up with one: 1 <enter> 2 <enter> +. RPN users know what that gives and inevitably end up with a miscalculation on a 20b in RPN mode, since they don't see the difference before the operation is done. Identifying that there's a problem is only easily possible if they know the answer anyway.

Why would you want to break a standard? Ask for the 34s to become an RPL calculator. See the difference?

No, there's nothing wrong with an edit register otherwise. It was probably absent since registers were expensive back then. But it is a part of RPL machines, not RPN machines.

Imagine this: What if you're used to chain mode and all of a sudden a calculator in chain mode uses precedence rules? That would be irritating and plain silly.

[walter b]

(12-19-2013 05:16 PM)eri Wrote:  ... why stop at a stack with only 8 elements? And after we have a memory limited stack I'm going to complain about lacking objects: units and symbolic math.

A stack with 8 elements is all you'll ever need on an RPN calculator.
Units are something you'll never need when working in SI.
Symbolic math? It's going to be a calculator, not a mathematician.

Never forget the pocket knife paradigm.

d:-)

[walter b]

(12-20-2013 06:57 AM)eri Wrote:  Yeah really. Not exactly complaining about this fantastic tool. Using it every day. Love it. $15. I sure would pay more for better keys though.

Thanks for your kind words.

Pauli made some attempts to get HP to produce some keyboards for the WP 34S. IIRC, the lower limit for a production run would have been some 10 000 pieces and about as many $ for tooling -- please compare with the number of WP 34S living on this planet so far. We are two orders of mangnitude below that limit AFAIK.

d:-/

[Howard Owen]

(12-19-2013 05:16 PM)eri Wrote:  "Strictness"... "decades": RPL has been around for decades too...

Yes it has. And, like the classic RPN machines, RPL machines from HP have been superseded by a new programming model on a machine with much greater horsepower. That suggests to me that there is room for an enthusiast's RPL calculator along the lines of the WP-34s.

Leaving aside the problems of obtaining a suitable hardware platform and, more importantly, volunteer expertise and commitment, I see one other difficulty. The corpse of RPL is not only still warm, it is still breathing in the form of the HP-50g. Perhaps it's too early to embark on such a project.

[Les Bell]

(12-20-2013 10:37 AM)walter b Wrote:  A stack with 8 elements is all you'll ever need on an RPN calculator.

Amen!

(12-20-2013 10:37 AM)walter b Wrote:  Units are something you'll never need when working in SI.

True, that!

(12-20-2013 10:37 AM)walter b Wrote:  Symbolic math? It's going to be a calculator, not a mathematician.

Halleluiah!

(12-20-2013 10:37 AM)walter b Wrote:  Never forget the pocket knife paradigm.

Praise the Lord!

Sorry - got carried away in rapture for a few moments, there.

[Paul Dale]

Early on, I asked HP about the possibility of a custom device. 2k units was the suggested minimum to even discuss custom firmware on the standard hardware. 10k was for a custom LCD. Needless to say, discussions didn't progress from there. If someone is willing (or mad enough) to sponsor this kind of quantity, I'd love to buy a couple of properly finished units. If anyone is insanse enough to consider a custom LCD, we could do a little better.

The 34S might, at a stretch, have about 500 units worldwide so we're not even close.


- Pauli

[walter b]

(12-21-2013 11:12 AM)Paul Dale Wrote:  Early on, I asked HP about the possibility of a custom device. 2k units was the suggested minimum to even discuss custom firmware on the standard hardware. 10k was for a custom LCD. Needless to say, discussions didn't progress from there. If someone is willing (or mad enough) to sponsor this kind of quantity, I'd love to buy a couple of properly finished units. If anyone is insanse enough to consider a custom LCD, we could do a little better.

The 34S might, at a stretch, have about 500 units worldwide so we're not even close.

Didn't they say anything about custom keyboards, too?

d:-?

[bhtooefr]

(12-20-2013 05:43 PM)Howard Owen Wrote:  That suggests to me that there is room for an enthusiast's RPL calculator along the lines of the WP-34s.

Leaving aside the problems of obtaining a suitable hardware platform and, more importantly, volunteer expertise and commitment, I see one other difficulty. The corpse of RPL is not only still warm, it is still breathing in the form of the HP-50g. Perhaps it's too early to embark on such a project.

I'm wondering how open HP would be to open sourcing the 50g firmware, actually (even though it *IS* going to be a mess of old Saturn-era code, third-party code, and ARM code), once it's discontinued. (It might be a bit too optimistic to ask that while it's still available, really.)