old HP ad in 1974 Scientific American


While thumbing through an old 1974 Scientific American today, I came across
ad. Very interesting.


Indeed! Very rational arguments, very honest impression. On the other side, you have to spend the time to read it. Very few people would do this today. Such a repelling amount of text! Small print!!No pictures!!! Seems those HP guys want to make us thinking :( Ooooh, that's what we do not like! Different times...


That is priceless!

I've never heard the arguments for RPN stated better. Imagine a company whose marketing department would produce something like that - practically unadulterated geek-speak - aimed squarely at SA's technically minded readership.

Marketdroid: Why in the #?@%! did you make these calculators so hard to use??

HP Engineer: They are not hard to use. They're easier, in fact.

Marketdroid: But where's the equals button? It's just weird!

HP Engineer: <Long, geeky explanation of RPN's advantages>

Marketdroid: <eyes glazing over> OK, OK, you write the copy!



So the big question is: did anyone send for the Enter vs. = booklet? I'd like to see that.



There is the rpnvsalg.pdf in the MoHPC DVD, and I could have sworn I saw the ENTER vs = leaflet there as well, although I can't find it now.

So I simply scanned my copy and you can find it here:



I enjoyed reading the article. I like RPN and still do. But in all fairness the AOS system has come a long way and RPN is still the same. RPL can be an improvement on RPN or not.


The main advantage of the newer (RPL) machines over the classic RPN calculators is the visible stack of practically unlimited depth and the seamless integration of other data types (matrices, complex numbers, lists, ...).

The main advantage of modern algebraic calculators is the editable equation line which you can simply pick and reexecute from history.



Dia C. Tran wrote:

But in all fairness the AOS system has come a long way and RPN is still the same.

I would submit that AOS needed to come a long way to appraoch the usability of RPN. IMHO, even with modern command line AOS machines, doing a really big calculation can be tedious, as you have to "build" the calculation in the command line. I find it quite clumsy when the calculation you are building exceeds the display width and you have to scroll.

Building an algebraic object in textbook format (ie, equation mode on a 48G), is certainly much better, as a big equation is much easior to read, but that's not really a command line, is it.

In all fairness, my "modern" AOS with command line experience has been with my 33s in ALG mode. Maybe TI has made the command line even easier to use on their new machines.

Best regards, Hal


The 33s is not a very good AOS calculator as you can't replay and edit previous equations as you can with various TI, Casio and Sharp models.




You are absolutely right. The hp 33s really isn't a good algebraic calculator. Is anyone surprised? The HP folks have never really believed in algebraic, just as the TI folks have never really believed in RPN. The algebraic mode of the hp 33s is crippled by keyboard limitations. No algebraic guy wants to tolerate parentheses as a second function. Suppose some vendor made a calculator with a primary mode which is algebraic and a secondary mode which is RPN and made the ENTER key a second function? What would the RPN guys think?

Even so, the 33s can do some fairly powerful stuff. My main objections to the machine are the limited number of labels, the limited number of data registers, the use of the archaic I register methodology and the lack of a means to move programs from one machine to another. Is the fourth item tied into the NCEES rules?


Hi Palmer. The 49G+ / 50G are slightly better at AOS than the 33s. At least you can replay and modify the three equations visible on the stack which is far fewer than on a HP 30s, TI, Casio or Sharp. Also the clear (left shift, <- ) doesn't work in AOS mode. Parentheses are also shifted and disappear after Enter is pressed.

Back to RPN for me!




RPN is still the same because there wasn't anything wrong with it. AOS was deficient in various ways, some of which have been corrected.



Coud you tell more about theses corrections please ?



So-called "algebraic" calculators used to use postfix notation for trig and logarithmic functions, contrary to actual algebraic notation. many current or recent algebraic calculators now use prefix notation for these functions.


Hi Patrick,
The existance of a command line is probably the biggest single improvement to AOS...it lets you see the big picture of the calculation your keying in (ie, parenthesis, etc).

If you've ever used an early AOS machine with no command line, like a TI58, it can be very tedious just keying in a big calculation, because you must mentally track your levels of parenthesis (there is no indication in the display of how many levels of parenthesis you have open).
If you loose track of where you are (ie, did I just close 5 or 6 levels of parenthesis...?), you usually have to start over.

Best regards, Hal



Thanks to both of you for your answers.

Yes, I bought a TI 57 when I was 13 and spent many afternoons playing with it, then I bought some Sharp (PC 1255) and Casio (FX 502P, FX 702P). I dreamt of HP but couldn't afford them. I bought a HP 32SII and then a HP 12C many years later.

Indeed, I had to redo many calculus after having lost the count of parenthesis... ;o)




IMHO, RPN is still superior to a command line because you can see every intermediate result.




Thank you very much.



I've been an RPN user and advocate since 1980. I find it interesting that even though HP marketed RPN as being superior to AOS they eventually added AOS to their calculators.




I've been an RPN user and advocate since 1980. I find it interesting that even though HP marketed RPN as being superior to AOS they eventually added AOS to their calculators.

Three words: defeat in market.




The "defeat in market" stemmed from several things:

1. Recognition that the educational market was different from the engineering/scientific market and adjustment of the sales effort accordingly.

2. After sales support.

3. Price.

And, a new insight on use of the hp 33s. While doing some programming last night the machine went from totally operational to dead as a doornail in a few seconds. I suspect that the battery annunciator was on but that I failed to notice it. I lost all the programs. When I checked the batteries I found the open circuit voltages to be 1.4 and 2.3 volts. Replacement of either one yields a working machine with the battery annunciator off; however, with the 1.4 volt battery in place the battery annunciator comes on in a few minutes and the calculator shuts down shortly therafter.

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