HP Forums

Many sources say that the ENTER behavior introduced with the 48 (the key does not push the stack) is "used by later HP calculators", but this (ambiguous) statement isn't quite right: it's used by some later HP calculators (e.g., it's not used in the 35s).

What models use this behavior? Is there a rationale for it (or for introducing it and then not using it in some later models)? Are there any options to enable or disable it on any models (e.g., as on PCalc)?

That's the RPL stack behavior, which applies mainly to the 28, 48, 49, and 50 models.

Any thoughts on the reasons for the switch to that behavior, and then back to the "old" behavior?

(03-10-2020 04:00 PM)Orome Wrote: [ -> ]Any thoughts on the reasons for the switch to that behavior, and then back to the "old" behavior?

Because the 35S wasn't RPL. It was the old 4-level RPN stack (and ENTER behavior) like the 33S and 32SII it succeeded. The 12C and 17B also stuck with the older RPN, despite still being in production long after the 28 and 48 came out. It's just two different styles with differing levels of complexity in usage, and they both have their target audiences.

Dave Britten Wrote: [ -> ]Because the 35S wasn't RPL...

I'm wondering more from a UX perspective whether there was a motivation for it

I know some people have strong feelings about it too, so even of the behavior is effectively a side effect of using RPL, it has UX implications as a feature on its own (and presumably could easily have been implemented either way regardless of RPN vs RPL).

Dave Britten Wrote: [ -> ]It's just two different styles with differing levels of complexity in usage, and they both have their target audiences.

So that's really my question: what were considered the "styles" and "audiences" targeted by each behavior for ENTER.

I don't have an answer to your question but I may have information that can help you answer it.

The "HP-48 style" enter is used on calculators that deal with...

• A Command Line (Entry Line in Prime's case)
• The stack deals with many, many different types of objects.
• Tend to have a large stack.
  

The "old" behavior, as you call it, is used on calculators that have...

• 4 or 3 level stacks.
• Input numbers directly on the stack through the X-register.
  

I believe these are the main differences that would influence the different ENTER key behaviors. I can't think of any more at the moment.

Keep in mind HP never abandoned either styles and both are used in today's HP calculators.

Perhaps reading a copy of Bill Wickes' HP-28 Insights might yield a good explanation for the birth of RPL "straight from the horse's mouth". Another shorter explanation might be from Bill's August 1987 HP Journal article "An Evolutionary RPN Calculator for Technical Professionals".

Jake

When system gets more complex, consistency is preferred over keystrokes count.

see Paul Dales old posts ...
https://www.hpmuseum.org/forum/thread-19...l#pid18041
https://www.hpmuseum.org/forum/thread-19...l#pid18094

Albert Chan Wrote: [ -> ]When system gets more complex, consistency is preferred over keystrokes count.

It's funny I never saw it as a consistency thing. I was once convinced that the 48-style ENTER made more sense, but now I can't for the life of me recall why I thought that. Now the other way makes more sense to me.

Carsen Wrote: [ -> ]I don't have an answer to your question but I may have information that can help you answer it.
...
I believe these are the main differences that would influence the different ENTER key behaviors. I can't think of any more at the moment.

That's a big help. I hadn't really thought of it that way before, but that makes a lot of sense from a UX perspective.

(03-10-2020 07:33 PM)Jake Schwartz Wrote: [ -> ]Perhaps reading a copy of Bill Wickes' HP-28 Insights might yield a good explanation for the birth of RPL "straight from the horse's mouth". Another shorter explanation might be from Bill's August 1987 HP Journal article "An Evolutionary RPN Calculator for Technical Professionals".

Jake

Also, read "HP41 / HP48 Transitions", Chapter 2. from the same horse (Bill Wickes). As this issue was one of the obstacles to many 41 users transitioning to RPL, Bill covers it in good detail and is probably the best coverage on the topic. By coincidence, I was just re-reading this while on vacation last week, the explanation of the subtleties involved is excellent.

Both books are included in the MoHPC document set, here:

https://www.hpmuseum.org/cd/cddesc.htm

As you're new here, I strongly recommend you get this collection. There are more than 1700 documents/manuals/books/guides/etc. and nearly every topic that comes up eventually leads to pointers to docs in the set.

rprosperi Wrote: [ -> ]I strongly recommend you get this collection.

Done!

(03-11-2020 03:09 PM)Orome Wrote: [ -> ]

rprosperi Wrote: [ -> ]I strongly recommend you get this collection.

Done!

Decisive, quick, wise, and clear evidence of HP addiction.

You'll fit in here, so welcome!

(03-10-2020 11:00 PM)rprosperi Wrote: [ -> ]By coincidence, I was just re-reading this while on vacation last week, the explanation of the subtleties involved is excellent.

Wow, that's my kind of vacations, not sure my wife would agree though.

(03-11-2020 05:06 PM)Sylvain Cote Wrote: [ -> ]

(03-10-2020 11:00 PM)rprosperi Wrote: [ -> ]By coincidence, I was just re-reading this while on vacation last week, the explanation of the subtleties involved is excellent.

Wow, that's my kind of vacations, not sure my wife would agree though.

She got the massage and spa treatment, I got to read Wickes 41/48 Transitions and another book about the development history of the Lockheed XF-90 Fighter. Each of us believes we got the better part of the deal. Been a long time since I've had such a great vacation. Oh, we got to see Cancun, Mexico too.

rprosperi Wrote: [ -> ]... "HP41 / HP48 Transitions" ... included in the MoHPC ...

Any idea where a print version might be available? It seems to be unavailable from the usual general book places.

(03-12-2020 12:55 PM)Orome Wrote: [ -> ]

rprosperi Wrote: [ -> ]... "HP41 / HP48 Transitions" ... included in the MoHPC ...

Any idea where a print version might be available? It seems to be unavailable from the usual general book places.

[attachment=8147]
Here it is, right from my bookshelf. :)
NFS, sorry.

(03-12-2020 01:56 PM)Massimo Gnerucci Wrote: [ -> ]Here it is, right from my bookshelf.

Show off! ... more HP-48 books here

(03-12-2020 12:55 PM)Orome Wrote: [ -> ]Any idea where a print version might be available? It seems to be unavailable from the usual general book places.

It took me many years to get my copy, finally got it middle of last year. It's pretty rare and usually expensive, I've seen it listed for over $200, but if you're willing to wait a while, you can probably still get it for under $100. You're more likely to get a better deal on eBay believe it or not, on ABE/Amazon it will almost certainly be much higher.

But I know there is a copy in Milan, that.... Oh wait. Sorry, no... never mind...

(03-12-2020 11:44 PM)rprosperi Wrote: [ -> ]

(03-12-2020 12:55 PM)Orome Wrote: [ -> ]Any idea where a print version might be available? It seems to be unavailable from the usual general book places.

It took me many years to get my copy, finally got it middle of last year. It's pretty rare and usually expensive, I've seen it listed for over $200, but if you're willing to wait a while, you can probably still get it for under $100. You're more likely to get a better deal on eBay believe it or not, on ABE/Amazon it will almost certainly be much higher.

Yes, I concur: I've got mine from eBay for well under $100, but that was several years ago.

(03-12-2020 11:44 PM)rprosperi Wrote: [ -> ]But I know there is a copy in Milan, that.... Oh wait. Sorry, no... never mind...

Oooops: just coughed on it! Now it's gone 'viral', you know...

(03-12-2020 04:38 PM)Sylvain Cote Wrote: [ -> ]

(03-12-2020 01:56 PM)Massimo Gnerucci Wrote: [ -> ]Here it is, right from my bookshelf.

Show off! ... more HP-48 books here

About books, these are the prices that I have paid for the HP-48 books that I have in my collection:

HP-48S/SX English Books:

HP-48G/GX English Books:

HP-48S/SX French Books:

HP-48G/GX French Books: