RPN programmability moved backwards?

[David Hayden]

I was perfectly happy with my 41CV purchased around 1981, so I missed all the calculator fun from 1981 until about 2006 when I got a 50g to see what HP had been up to.

Over the past few days I did some programming on the 35s and found it much harder than the 41C (or DM42 or WP-34s). Only 26 labels, each consisting of just one letter, just two, hardcoded, indirection registers, cumbersome code if you want both direct and indirect access to registers. Yuck...

Looking through my manuals, it seems that this started with the 32s in 1988.

Does anyone know why HP took this course of reduced programmability? Maybe people just weren't writing programs as much? Certainly the non-programmable functionality git better and better and the RPL machines are highly programmable, but the RPN calcs seemed to go backwards rather than forwards.

Dave

[Jeff O.]

(10-04-2019 03:55 PM)David Hayden Wrote:  ...Does anyone know why HP took this course of reduced programmability? ...

My two cents, which may or may not be worth even that much.

I don't think that the programmability of the 35s is best viewed as a reduction. I would view it more like 35s and 42s being descended from a common ancestor, but living on different branches of the RPN programmability tree. The 35s was more or less a successor to the 32s series, which had relatively limited programmability. The 42s and 32s were introduced at essentially the same time, with the 42s continuing and expanding on the advanced programmability of the 41C, while the 32s advanced the original "classic" RPN programmability of the 11C (and previous models like the 65, 67, 25, 29, 33C). The evolution of advanced RPN programmability stopped with the 42s, while the 32s “evolved” into the 32sii, 33s and finally the 35s. Or something like that.

[Valentin Albillo]

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Hi, David:

(10-04-2019 03:55 PM)David Hayden Wrote:  Over the past few days I did some programming on the 35s and found it much harder than the 41C (or DM42 or WP-34s).

Well, the HP35s does have many (mostly stupid) limitations and bugs, that's why I put it away in storage after an exciting period of testing its capabilities, but nevertheless during that brief period (some months) I did write a number of programs for it (see this one, Going Back to the Roots), and came to appreciate some aspects of its programming paradigm, for instance its equations handling is extremely powerful and does allow for very interesting, efficient programs as the link above clearly demonstrates.

Quote:Certainly the non-programmable functionality git better and better and the RPL machines are highly programmable, but the RPN calcs seemed to go backwards rather than forwards.

I dissent. If you get to really know its advanced techniques, the HP35s is more than a match for the programming model (not capabilities, i.e.: no ROMs, I/O, etc) of the pure RPN HP-41C. And if you'd rather stick to the pure RPN model, then the HP42S provides a much more poweful, much enhanced RPN progamming than anything the HP41C has to offer: named variables, matrices, complex numbers and operations, menus, graphics, etc., etc., etc.

Not "backwards" at all.

V.

P.S.: This is my #400 post in this new forum (a lot more than 2,000 overall)
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[David Hayden]

(10-04-2019 04:40 PM)Valentin Albillo Wrote:  If you get to really know its advanced techniques, the HP35s is more than a match for the programming model (not capabilities, i.e.: no ROMs, I/O, etc) of the pure RPN HP-41C. And if you'd rather stick to the pure RPN model, then the HP42S provides a much more poweful, much enhanced RPN progamming than anything the HP41C has to offer:

Thanks for the comments, Valentin, and especially for the link to your article. I didn't realize that equations could be used on the 35s that way.

But still, I wish that they had added such features on top of the robust and easy to use features of the 41C or 42s model. Maybe it's just me, but I find programming the 35s much more difficult than programming the 41C or 42s

Jeff O Wrote:the 32s advanced the original "classic" RPN programmability of the 11C (and previous models like the 65, 67, 25, 29, 33C) [and] “evolved” into the 32sii, 33s and finally the 35s. Or something like that.

That's an interesting point, especially when looking at the low price of the 32s ($70). Maybe they couldn't put the advanced programming model of the 42s into the low cost 32s. The 32sii and 33s look like upgrades and the 35s probably reused much of the 33s code.

[Valentin Albillo]

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Hi again, David:

(10-04-2019 08:15 PM)David Hayden Wrote:  Thanks for the comments, Valentin, and especially for the link to your article. I didn't realize that equations could be used on the 35s that way.

You're welcome. For a much more complex example of using HP35s' equations have a look at my article Storing lotsa lotsa numbers.

Equations used this way are a very powerful mechanism and I wish HP would have included them in the HP42S (optimized to be sure, i.e.: parsed just once upon entry as a program line, not every time the running program executes the line, if nothing else).

Have a nice weekend, and while you are at it visit my new HP site (link below in my signature)
V.
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