The Museum of HP Calculators

HP Forum Archive 19

[ Return to Index | Top of Index ]

RPN is an addiction
Message #1 Posted by Peter Klein on 11 Feb 2009, 3:01 a.m.

Unlike most of you, I'm not an engineer or a programmer. I'm just a humanities guy cleverly disguised as a computer and network support person for economic purposes. And my mathematical needs are modest.

But I'm a confirmed RPN addict. I started back in 1976 with a simple National Semiconductor RPN calculator, soon replaced with an HP-25.

I taught myself some math and programming on the "25." I wrote a simple program using the HMS<->H functions to add up timings for classical music recordings when I worked in public radio. I wrote a program to calibrate the bandspread dial of an old Hallicrafters shortwave radio for the international broadcast bands, so I could find stations without hunting. Trivial stuff, but useful.

Eventually I got my beloved 11C, which I still use, albeit mostly to balance my checkbook. There are only two things I wish were different about the 11C:

- I wish it did hex/octal/binary math.

- I have big hands, so I wish the spaces between the number buttons were bigger. I need about 4mm or more of space between the left side of the "1" button and the right side of the "3" button to be comfortable "touch keying."

Recently, I pulled out my old HP-25, and discovered that the program memory, registers and Last X no longer hold any values. And I though, "Uh-oh, what if the 11C bites the dust?" So I began searching, and found out about the new 35s. But I read about the keyboard issues, the virtually unusable hex entry, and the shifted "STO" function, and I thought, "No, I probably wouldn't be happy with this."

So they don't make what I want. I'm kind of stuck. Algebraic calculators just don't cut it for me. The big graphing calculators are overkill for my needs. I wish HP still made something like the 32s or 42s, which would probably be fine for me. But even those are getting old these days, and cost plenty.

And here I am, longing for the proverbial Good Old Days. Those old HP calculators are an addiction, that's for sure.

      
Re: RPN is an addiction
Message #2 Posted by Nigel J Dowrick on 11 Feb 2009, 7:10 a.m.,
in response to message #1 by Peter Klein

I probably won't get too much support for the opinion I'm about to express, but I think that the HP-33S is worth considering if what you want is a scientific RPN machine. In many people's eyes it is not a thing of beauty, and it doesn't have that magic double-sized ENTER key. However, a lot of the negative opinions you'll find online refer to the first version which really did have major quality issues. I've used my later version heavily for several years. The keyboard is fine; the display is beautifully clear. It has unshifted STO, RCL, 1/x, x^2, and sqrt(x) keys. It's light and feels comfortable in use. I don't have a 35S to compare it to, but from the reviews I've read I like my HP 33S better! Then again, you shouldn't always believe reviews...

            
Re: RPN is an addiction
Message #3 Posted by Don Shepherd on 11 Feb 2009, 7:25 a.m.,
in response to message #2 by Nigel J Dowrick

I second that. I have an early 33s with the small decimal point, but it has never bothered me, and I don't mind the chevron layout either. Other things I like about it:

  • the keys are spaced well to accomodate large fingers
  • you can document your programs with comments, using EQN
  • bases hex, oct, and bin work like they should
  • the program execution speed is orders of magnitude faster than the 35s; it is FAST FAST FAST
  • it has linear regression
  • it is recent enough that you can buy it cheaply
            
Re: RPN is an addiction
Message #4 Posted by Jeff Kearns on 11 Feb 2009, 9:54 a.m.,
in response to message #2 by Nigel J Dowrick

I also agree with you, regrettably... The HP-33s, despite its non-traditional design, is what the 32sii should have been. My biggest gripe with the 32sii was the pitiful amount of memory it had - but it is such a great little machine!

The 33s is better than the 35s (I have one of those too) in so many ways, keyboard layout (ignore the chevron), polar to rectangular, checksums that mean something, and unshifted STO to name a few. It does lack the practical ability to use all that memory with the small number of storage registers for labels etc., but it is so much faster! Karl Schneider has commented elsewhere on why this is so.

Despite all the negative reviews that the 33s has received, I would recommend it over the 35s in your case. Good luck!

Jeff Kearns

                  
Re: RPN is an addiction
Message #5 Posted by Karl Schneider on 12 Feb 2009, 2:31 a.m.,
in response to message #4 by Jeff Kearns

Hi, Jeff --

Quote:
... it (the HP-33s) is so much faster (than the HP-35s) ! Karl Schneider has commented elsewhere on why this is so.

I believe that you're referring to this thread:

http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv017.cgi?read=124094#124094

I suspect that the HP-35s is slower than the HP-33s in order to provide respectable battery life. The thread comparing speeds to the HP-32SII was in reference to numerical integration, for which the HP-33s/35s used a different means of specifying uncertainty than did the HP-32SII. In some cases, the HP-33s/35s would be slower.

More about integration uncertainty:

http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv016.cgi?read=96784#96784

-- KS

Edited: 12 Feb 2009, 2:57 a.m.

                  
Re: RPN is an addiction
Message #6 Posted by Ed Look on 13 Feb 2009, 12:40 p.m.,
in response to message #4 by Jeff Kearns

You know, initally, I truly believed the 35s was better than the 33s; in terms of cosmetics, as in the keyboard layout, overall color scheme of the machine, and the cute zipper case, I still do believe.

However, over the time I have owned and used the 35s, I find the 33s to be more user-friendly, even, I daresay, for scientists, engineers, surveyors, etc. The choice of functions on the unshifted keys are much more convenient.

Quote:
I also agree with you, regrettably... The HP-33s, despite its non-traditional design, is what the 32sii should have been. My biggest gripe with the 32sii was the pitiful amount of memory it had - but it is such a great little machine!

The 33s is better than the 35s (I have one of those too) in so many ways, keyboard layout (ignore the chevron), polar to rectangular, checksums that mean something, and unshifted STO to name a few. It does lack the practical ability to use all that memory with the small number of storage registers for labels etc., but it is so much faster! Karl Schneider has commented elsewhere on why this is so.

Despite all the negative reviews that the 33s has received, I would recommend it over the 35s in your case. Good luck!

Jeff Kearns


      
Re: RPN is an addiction
Message #7 Posted by Allen on 11 Feb 2009, 7:57 a.m.,
in response to message #1 by Peter Klein

Quote:
Those old HP calculators are an addiction, that's for sure.

Fully agreed.

            
Re: RPN is an addiction
Message #8 Posted by Mike Reed on 12 Feb 2009, 10:35 a.m.,
in response to message #7 by Allen

Hello, My name is Mike, and I'm an RPN user... (hello, Mike)

It all started back in the 70's with an HP-11c, and that was SWEET! It wasn't long though till I got into heavier stuff: the HP-41's and synthetic programming, then HP-45's, HP-67's and worse to follow. I kept it under control pretty much till HP-came out with the HP-48sx; RPL pretty much took over my life and the HP-48GX only made it worse. I used the HP-32s, Hp-33's and HP-42s for everyday, and an HP-200 for fieldwork, but they couldn't match the high from the HP-48's. I thought maybe I could get off RPN/RPL myself, but then HP-introduced the 49 - a bad fix for sure. I ALMOST beat it when the HP-50 came out and now I'm hooked even more! It's not just RPN anymore, now it's HPGCC too! I can't even THINK about using a standard algebraic anymore! My kids won't let me help them with their math homework; they are afraid they might get my addiction. Fellow workers don't ask to borrow my calculator, or help solve their math problems. I don't know what to do. Please help. Thanks for listening to me.

                  
Re: RPN is an addiction
Message #9 Posted by Steve Simpkin on 12 Feb 2009, 11:32 a.m.,
in response to message #8 by Mike Reed

LOL

It's OK Mike.

The good news is that you are among friends that share your addiction and understand the profound satisfaction you get from seeing, touching and using your HP RPN calculator.

The bad news is that once infected, there is no know cure. In fact, most RPN addicts would not take a cure even if it was offered to them.

I don't know what would happen to my sanity if I stopped using RPN, but I'm not about to find out.

Steve

                        
Re: RPN is an addiction and I am Cured
Message #10 Posted by bill platt on 12 Feb 2009, 11:46 a.m.,
in response to message #9 by Steve Simpkin

I am finally cured. I am far less RPN dependent now than I was when I discovered the museum years ago. Paradoxically my exposure to all of these RPN types opened my eyes to other solutions--because we have a wide ranging group of thinkers and communicators here, I learned about the 27s, the Sharp PC series, the Casio ideas, etc.

Today, I like my 27S a lot. And I find that the 48/49/50 series is great for algebraic, too--I often put in algebraic objects within '...' and then evaluate.

When I use my 35S, for larger problems I go into equation mode rather than the stack, and work out a problem algebraically. No worries about running out of memory, you get to correct the input if it doesn't work, etc. Far superior to the simple RPN interface. I found the same idea useful in the ill-fated hp 30S.

Edited: 12 Feb 2009, 11:48 a.m.

                              
Re: RPN is an addiction and I am Cured
Message #11 Posted by Martin Pinckney on 12 Feb 2009, 2:27 p.m.,
in response to message #10 by bill platt

Quote:
Today, I like my 27S a lot. And I find that the 48/49/50 series is great for algebraic, too--I often put in algebraic objects within '...' and then evaluate... When I use my 35S, for larger problems I go into equation mode rather than the stack, and work out a problem algebraically... Far superior to the simple RPN interface.
At last! a former RPN nut has freely admitted that RPN does indeed have some shortcomings... :-)
                                    
Re: RPN is an addiction and I am Cured
Message #12 Posted by bill platt on 12 Feb 2009, 4:27 p.m.,
in response to message #11 by Martin Pinckney

Haha!

I can't take credit as the first though. That would be Valentin Albillo.

Or maybe even HP...I find this particular machine really interesting...

http://www.hpmuseum.org/hp9820.htm

"The calculator compiled each algebraic expression into an RPN style sequence. Such compilation of algebraic expressions was a common practice on larger computers of the time, however the HP 9820A went a step further by also providing an uncompiler that converted the internal RPN sequence back to algebraic. This allowed only the RPN version to be stored. All of this was automatic." -Dave Hicks (on this site)

      
Re: RPN is an addiction
Message #13 Posted by George Bailey (Bedford Falls) on 11 Feb 2009, 8:30 a.m.,
in response to message #1 by Peter Klein

Get the 35S. It's what we humanities guys need. It fully fulfills the needs you describe. Plus: it looks awfully good on your desk. And get a therapy for your addiction.

      
Re: RPN is an addiction
Message #14 Posted by Martin Pinckney on 11 Feb 2009, 8:33 a.m.,
in response to message #1 by Peter Klein

Quote:
So they don't make what I want. I'm kind of stuck. Algebraic calculators just don't cut it for me. The big graphing calculators are overkill for my needs. I wish HP still made something like the 32s or 42s, which would probably be fine for me. But even those are getting old these days, and cost plenty.

And here I am, longing for the proverbial Good Old Days. Those old HP calculators are an addiction, that's for sure.


Peter, I understand exactly where you are on this. But don't despair. I have solved my problem by buying used Pioneers off eBay. No, you cannot just decide to buy and order right away, like ordering from a retailer, but you can actually buy for reasonable prices, if you are patient. Although some 32sii go for $150, I have seen many in excellent condition go for around $80. Compared to $60 for 35s, and considering the quality difference, these are reasonable prices. There are other similar bargains to be had; the key is patience and perseverance.
      
Re: RPN is an addiction
Message #15 Posted by bill platt on 11 Feb 2009, 9:26 a.m.,
in response to message #1 by Peter Klein

Well, the way you feel is why the 32sii and the 11c get over $100 on ebay. Some of us are willing to pay what is effectively a very small token premium to get what we are accustomed to.

Best regards,

Bill

      
Re: RPN is an addiction
Message #16 Posted by Michael de Estrada on 11 Feb 2009, 11:15 a.m.,
in response to message #1 by Peter Klein

You stated,

"Uh-oh, what if the 11C bites the dust?"

It won't. In fact, it will probably outlive you. I bought my HP-15c brand new over 27 years ago, and have been using it nearly every day since then. It still works perfectly. I also gave my HP-11c to my boss, who is a real key-pounder, 20 years ago and it is also working to this day. The HP Voyagers are absolutely the highest quality and most durable calculators HP has ever made.

Also, your HP-25 may just need a new battery, so don't throw it away quite yet.

      
Re: RPN is an addiction
Message #17 Posted by Thomas Klemm on 11 Feb 2009, 9:00 p.m.,
in response to message #1 by Peter Klein

Quote:
I wish it did hex/octal/binary math.

You might find these two routines helpful to translate from decimal to binary and vice versa:

001 - 42,21,13   LBL C                024 - 42,21,14   LBL D         
002 -    44  0   STO 0                025 -    44  0   STO 0         
003 -        8   8                    026 -        8   8             
004 -       34   x<>y                 027 -       16   CHS           
005 - 42,21, 0   LBL 0                028 -       34   x<>y          
006 -        1   1                    029 - 42,21, 2   LBL 2         
007 -        0   0                    030 -        2   2             
008 -       34   x<>y                 031 -       34   x<>y          
009 -        2   2                    032 -        1   1             
010 -       10                       033 -        0   0             
011 -   43  44   INT                  034 -       10                
012 -   43  40   x=0                  035 -   43  44   INT           
013 -    22  1   GTO 1                036 -   43  40   x=0           
014 -       33   R-v                  037 -    22  3   GTO 3         
015 -       20                       038 -       33   R-v           
016 -       33   R-v                  039 -       20                
017 -       20                       040 -       33   R-v           
018 - 44,40, 0   STO + 0              041 -       20                
019 -       33   R-v                  042 - 44,40, 0   STO + 0       
020 -    22  0   GTO 0                043 -       33   R-v           
021 - 42,21, 1   LBL 1                044 -    22  2   GTO 2         
022 -    45  0   RCL 0                045 - 42,21, 3   LBL 3         
023 -   43  32   RTN                  046 -    45  0   RCL 0         
                                      047 -   43  32   RTN

Example:

45 GSB C         101101
10011 GSB D      19

Hint: Exchanging 2 and 8 in the program will result in a dec-oct converter.

      
Re: RPN is an addiction
Message #18 Posted by John B. Smitherman on 11 Feb 2009, 10:03 p.m.,
in response to message #1 by Peter Klein

Peter, you should consider a 12c or 12cp. Although it's weak on scientific functions a 12c would provide the same form factor and keystroke programming paradigm as your 11c. The 12c could serve as an RPN four banger while the 11c could be reserved for other uses.

Regards,

John

            
Re: RPN is an addiction
Message #19 Posted by bill platt on 12 Feb 2009, 10:00 a.m.,
in response to message #18 by John B. Smitherman

The keystroke programming on the 12c is not the same paradigm as the 11c. The 11c is much better--the 12c is crippled in this respect. No editing allowed. You have to use a GTO pair and append modifications to the end of the program.

Edited: 12 Feb 2009, 10:00 a.m.

      
Re: RPN is an addiction
Message #20 Posted by Steve Simpkin on 12 Feb 2009, 2:58 a.m.,
in response to message #1 by Peter Klein

Quote:
"But I'm a confirmed RPN addict. I started back in 1976 with a simple National Semiconductor RPN calculator, soon replaced with an HP-25."
Too too weird. My first RPN calculator was a National Semiconductor Mathematician that I bought used around 1976. http://spyropoulos.net/calcs-other/4510Mathematician.jpg

I had been lusting after the HP-25 since I saw one in a Canadian department store in 1975. I couldn't afford it at the time so I ended up getting the Mathematician. I finally bought my HP-25 in 1977. I used it through high school, college and the first few years of work. After it started to malfunction in 1987, I replaced it with a HP-11C. I eventually moved onto a HP-28C, HP-28S, HP-48SX and HP-48G.

Quote:
"I wrote a program to calibrate the bandspread dial of an old Hallicrafters shortwave radio for the international broadcast bands, so I could find stations without hunting."
I still have my Hallicrafters tube shortwave radio!

Quote:
"Eventually I got my beloved 11C"
Me too.

Quote:
"Recently, I pulled out my old HP-25, and discovered that the program memory, registers and Last X no longer hold any values."
My HP-25 went through a year or two in the late 1980's where it would malfunction but it was just temporary and it works fine now! DO NOT CONNECT A CHARGER TO THE HP-25!!!! Use alkaline batteries instead.

Quote:
"Algebraic calculators just don't cut it for me."
I find I feel dirty after using an algebraic calculator. Is that wrong?

Quote:
"The big graphing calculators are overkill for my needs. I wish HP still made something like the 32s or 42s, which would probably be fine for me."
I have to agree with the other posters here about the HP-33S. I received a HP-33S as a joke gift from my wife (she heard me comment on how ugly it was). I was pleasantly surprised at how good a calculator it is (after you get over the looks of it). Got it refurbished for around $20 on eBay.

Quote:
"And here I am, longing for the proverbial Good Old Days. Those old HP calculators are an addiction, that's for sure."
I don't consider my obsession with HP calculators an addiction. I could stop if I wanted to. I just don't want to!
            
Re: RPN is an addiction
Message #21 Posted by Peter Klein on 12 Feb 2009, 3:23 p.m.,
in response to message #20 by Steve Simpkin

Quote:

Too too weird. My first RPN calculator was a National Semiconductor Mathematician that I bought used around 1976. http://spyropoulos.net/calcs-other/4510Mathematician.jpg ...I finally bought my HP-25 in 1977. I used it through high school, college and the first few years of work. After it started to malfunction in 1987, I replaced it with a HP-11C.


Steve: This is indeed too weird, I had the same National Semiconductor model. That and Hallicrafters, too. :-)

--Peter

Edited: 12 Feb 2009, 3:50 p.m.

            
Re: RPN is an addiction
Message #22 Posted by Peter Klein on 12 Feb 2009, 3:48 p.m.,
in response to message #20 by Steve Simpkin

Thanks to everyone who responded. You're a really friendly group of "enablers." :-)

I just rediscovered something very helpful. There is a great generic do-everything RPN calculator for Windows called Excalibur. It isn't specifically an HP emulator, but it was clearly inspired by the HP line. The usual freeware disclaimers apply, particularly with respect to floating point accuracy on a PC.

I'd used Excalibur before, but forgotten about it. The latest version is here: http://www.geocities.com/dbergis/freeware.htm

Excalibur has good binary/hex support, so I can just use that at work when I occasionally need it. With that, I really don't *need* to do anything more immediately. My 11C is still going strong.

So I can sit back and watch ads and see if an affordable sample of the "big hands friendly" later models appears. Getting a 12C as a spare four-function is certainly possible (they're plentiful and cheap). As is picking up a 33s, if I can get past the fact that the Enter key isn't where God and Hewlett ordained it to be.

Thanks again, everyone! --Peter

            
Re: RPN is an addiction
Message #23 Posted by bill platt on 12 Feb 2009, 4:29 p.m.,
in response to message #20 by Steve Simpkin

I wish I still had that Hallicrafters, and the National we had, too. My father and I were fixing them back in 1994. Then he sold his house and I was busy working and all that old tube Ham radio stuff went.

My father bought me my first calculator--an HP 11c --in 1982.

Edited: 12 Feb 2009, 4:29 p.m.

                  
Re: RPN is an addiction
Message #24 Posted by Howard Lazerson on 12 Feb 2009, 4:50 p.m.,
in response to message #23 by bill platt

Still using my 11c daily, no new batteries since 2007, nice feeling keys, nice display, more affection than addiction !

                        
Re: RPN is an addiction
Message #25 Posted by Steve Simpkin on 12 Feb 2009, 6:03 p.m.,
in response to message #24 by Howard Lazerson

I bought my HP-11C in 1987. I used it for many years until I sold it on eBay around 2001. I paid $58 for it new and sold it for $110 and it still had the batteries that it came with! 14 years of use and continuous memory on one set of batteries. Amazing by any standard.

            
Antique Radios to go with your HP
Message #26 Posted by Bill Platt on 12 Feb 2009, 6:54 p.m.,
in response to message #20 by Steve Simpkin

http://www.antiqueradiomuseum.org/hallicraftersradios.htm

                  
Re: Antique Radios to go with your HP
Message #27 Posted by Steve Simpkin on 12 Feb 2009, 7:47 p.m.,
in response to message #26 by Bill Platt

Mine was a Hallicrafters S40B.

Hallicrafters S40B Picture

And as a matter of fact it did go well with my HP-25!

                  
Re: Antique Radios to go with your HP
Message #28 Posted by Dave Shaffer (Arizona) on 12 Feb 2009, 8:55 p.m.,
in response to message #26 by Bill Platt

I started my ham radio operations in 1960 (when a freshman in high school) with a Hallicrafters S20R which my Dad had purchased just after World War II in 1946 (about when I was born!). This model receiver is shown on the bottom level of the rack in the picture in Bill's reference. This predates my HP addiction by 13 years! A few years after that, I blew my budget on a used SX101 MkIII.

For the electrical engineering afficionados amongst us, the S20R used the speaker coil as the smoothing choke in the DC power supply!

Up until about 10 years ago, my Dad still had that S20R receiver, but it seems to have disappeared when he and my mom moved to their retirement community.


[ Return to Index | Top of Index ]

Go back to the main exhibit hall