Slashdot Mirror
Recommendations for RPN Calculators?
sg3000 asks: "My trusty old HP 48S graphing calculator, that served me since engineering school, seems to be giving up the ghost. I haven't used it in a few years, but recently I put new batteries in it. It works, but it makes a loud static/white noise sound when it's on. The noise is not as noticeable when I hold it, but when I set it down on a hard surface, it's really loud. Then it sucks the batteries down incredibly fast (I put new batteries in it, and two days later, they were drained). Any suggestions on what I should buy as a replacement?"
"I'm in graduate school now, and since I'm taking an accounting course, where they don't want us digging out our laptops during a test, I need to buy another calculator. I'm a big fan of reverse polish notation (RPN), so I'd prefer to get another HP calculator.
Do companies still make calculators? I'd love to get another HP 48, but I'm not even sure if HP even makes calculators like that any longer -- on their web site, they're all cheapo-looking single line deals. I've read about something called an HP 48g, but HP has nothing about it on their web site."
Why does HP's current calculator lineup suck?
I have the HP48GX - it's a great calculator, but slow as molasses. According to this page HP will be releasing the 49G Real Soon Now(tm). I'll believe it when I see it, of course, but we can dream, right?
I have a HP 48GX and love it. If you can find one, get one.
I also wrote a GTK based one:
ghsilop.
Sounds like its power supply inverter is toast. Rip it apart, trace down the IC that is making all the noise (or look for a small IC mounted xformer near on IC) and do some home work. Replace what makes noise and what ic is a PWM if it has one, unless its home brew PWM inversion and learn.
Sorry, should have put the link in easy to click mode: HP 49G+
The RPNs worth buying are:
16C - awesome calculator for programmers, especially embedded work. There is no better number system converter available at any price. No I can't do bin/dec/hex in my head faster than the 16C and neither can you. Expensive due to relatively low numbers produced.
42S - pricey, even used, but excellent. Two line display, a replacement for the 15C.
32SII - somewhat like a 42S but with single line display, not so nice to use.
15C - same form factor as 16C. At the time HP's top scientific.
11C - a simpler 15C
10C - a simpler 11C
All the above have solid old-HP build quality, excellent key feel and outstanding battery life.
Older HPs are also usable (and may be preferred) - but they have even greater collector status and sometimes fetch higher prices. They will go through batteries faster and the red LEDs can be harder to see.
Forget the 48 models, the 49 and all the new stuff. The 48GX is OK if you have to have graphing but the single and dual-line models have better UI for daily use. The 49? HP died when Carly took over. Now they make pretty colored plastic boxes that only work with windows and they have forgotten how to spell "engineering". In fact they fired all the engineers and HP is now run by MBAs in shiny suits.
(I own 16C, 42s, 15C and 11C models.)
If you have a PalmPilot, you might consider RPN. Given your stated requirements, it may not be powerful enough, but it's served me well.
Schwab
Editor, A1-AAA AmeriCaptions
This sounds like subharmonic oscillation in the inductor core used in the DC-DC converter. Pop it open, find the inductor, and replace it - thing should be good as new.
Depending on how hard you work your calculator, you might do better to get a PDA and run a calculator program on it. If you bang on your calculator keys for hours, get a real calculator.
I use Palm PDAs (my current one is a Tungsten T) and I run a program called RPN on it. It's programmable and it has graphing, but I haven't used those features; but as a general-purpose RPN calculator, it's kept me happy.
What I really want is something similar to Palm RPN that is programmable in Python.
Anyway, the best thing about this is that I always have it with me. I used to have an HP calculator, but it was never handy when I wanted it.
steveha
lf(1): it's like ls(1) but sorts filenames by extension, tersely
Do you need a graphing calculator? If not go for HP's 32SII. I have one that I carry pretty much everywhere with me (my 48GX is a bit bulky and usually overkill).
On the other hand if you need to be able to graph get a HP 48G or 48GX. The GX is expandable but in my experience most people never end up using the expansion packs. Also HP is scheduled to release their new 49G+. Don't let the name fool you though. It is more like a 48 then a 49. None of thoes crappy soft-touch rubber buttons. Also it is based on some ARM processor that will be *much* faster then the 48s and 49.
What ever you do, stay HP. HP builds the best damn calculators on the market.
I'm afraid you're out of luck if you're looking for a new HP graphing calc. The HP32SII is nice, and there are still some sources around the internet (Amazon used to carry them), but it doesn't graph. The TI-83+ isn't a bad graphing calc, especially if you install this,
a slick RPN emulator...it preserves all the functionality of the TI-83+ while giving you the standard 4-register stack-based RPN functionality.
Contrary to what others here (your usual /. cranks with rose-colored nostalgic memories of ancient hardware) may tell you, the 49G is a great calculator despite the flaws in the design of the keys and display as well as the "new-wave" case. However, don't run out and buy a 49G now; HP is finally gearing up to release new calcs: the 49G+ and 48gII replace the aging Saturn processor (2-4 mhz, I forget what the process was but it probably was 3 microns or so) of older HP's like the 48S/SX/G/G+/GX and 49G with an ARM9 processor (48-75 mhz, probably a .18 micron process). (I think the ARM9 doesn't do quite as many IPC as the Saturn, and low-level saturn emulation will give some performance penalty, but still, this is going to be a lot faster- hpcalc.org just states it will be 3-7 times faster than the 49G, that's a pretty wide range). In addition, they appear to have fixed many of the case/key/display problems which plagued the 49G, and battery life should be about the same as it was for the earlier 48/49 series. I have absolutely no doubt that the new calcs will be fantastic deals.
Or just get yourself a PDA running version 5 of PalmOS (lower versions are supported for certain PDAs) and use an emulator to turn the PDA into your old HP48S.
:(
The emulator seems to get good reviews. Unfortunately it doesn't run on my Treo 90.
I'm in the same boat. I've returned to engineering graduate school after 7 years, and I've found an HP calculator emulator at the following website: http://power48.mobilevoodoo.com/
It works really well. Hope this helps.
Buy new(alkaline) batteries for it. I kid you not, it'll speed it up- if you haven't noticed, performance is noticeably dependent upon battery voltage, and the thing crawls when the batteries get low- possibly on purpose, I dunno.
I've had mine since the early 90's, and I never though of it as slow at anything except menus, graphing, and equation solving. For standard math and even running RPN programs, it's pretty quick- I never felt it was a 'hinderance'.
Please help metamoderate.
Reverse Polish Notation?!?!? Why exactly is it "Polish"?
Because a Polish man came up with the idea?
Prefix and Postfix notation were developed in the 1920's by Jan Lukasiewicz (who was, in fact, Polish). Prefix notation was often called Polish Notation in honor of Lukasiewicz.
Postfix turned out to be useful for computer operations, if you made it into a stack and then did operations upon that stack. It was called Reverse Polish Notation, since postfix is the opposite of prefix, and prefix was called Polish Notation.
Simple.
- Give a man a fire and he's warm for a day, but set him on fire and he's warm for the rest of his life.
I agree that keypresses saved are minimal, if not sometimes nonexistant in simple equations. In fact, for many simple single-operation equations, the process of learning RPN is far too complicated to justify using it at all.
RPN, however, can be likened to the Dvorak keyboard layout. It is entails a slightly involving process to learn. For many purposes, this is simply a pain. The true power only shines in complicated equations, such as those which make use of brackets.
The following equation shall be typed on an algebraic calculator, followed by an RPN calculator. [;] will be the button name for [Enter].
25 ( 46 ) + 254 - 2462 / ( 645 - 2453 )
Algebraic:
25*46+254-2462/(645-2453);
RPN:
25;46*254+2462;645;2453-/-
In the above example, you will realise that the number of keypresses is exactly the same. (In fact, if you cheat and leave out the second bracket on the algebraic calculator, that calculator edges out the RPN by one keystroke!) However, there are three immediate benefits to the RPN calculator:
Over time, the amount of keypresses will not really be changed too drastically. However, the true power is the convenience and the ease of use. Unfortunately, like the Dvorak keyboard, RPN will slowly fade in the non-specialised markets due to the fact that it takes too much time to learn.
And there are many occasions where the graphing functions of my TI have proved useful in the workplace. To name a few:
- being able to view every key I've entered before evaluating the expression
- being able to revise and edit incorrect expressions
- to determine linear regression fits for data sets
- to perform functions like logarithms and square roots on said data sets, in order to linearize them (linearity being checked, of course, by the R^2 correlation of my fit)
- anything at all to do with linear algebra, especially solving systems of equations or matrix manipulations. RREF is a bitch by hand.
For more "pure" math (like Diff. Eq.), I agree that pencil and paper are generally easier. But any applied math (a.k.a. engineering) requires an insane amount of busy work that could not be handled with a puny scientific calculator. I know you said Engineering and Physics are different stories, but everything I just wrote could certainly apply to all sciences (even the "soft" ones like Psych. and Sociology), or anything at all requiring data collection.
For the record, I use a TI-86 daily at a bio-tech job. It has the stats capabilities of the 83, plus all the good parts of the 85.
Si la vida me da palo, yo la voy a soportar Si la vida me da palo, yo la voy a espabilar
The calculator is slow to respond and update the screen, but it does have a wonderful type-ahead buffer. Once you're confident with the commands (takes time to memorize) and the buttons (their high quality makes it easier to trust), go ahead and type as fast as you want. The calculator will skip screen updates during this time, so you'll get the answer soon after you stop typing.
Once you know that secret, the speed isn't a problem (and I've got a 48S and a 48SX... that's a 1 MHz processor vs. the 2 MHz processor of the G's)
HIV Crosses Species Barrier... into Muppets
HP's new calculator division is based in San Diego. I was just at the HHC conference this past weekend, and the division director, marketing director, engineering manager, and lead software engineer were there. They seemed to be very concerned about customer feedback and fixing any problems (or perceived problems) with product quality.
Their first new high-end RPN calculator in four years is the HP 49G+, which will be officially announced in the US on October 6. (It's already available in some parts of the world.)
The HP 49G+ has similar capabilities to the HP 49G, but with a larger display (25% more pixels), faster processor (75 MHz ARM), more memory, better keyboard, USB interface, and an SD slot for flash memory expansion.
For One, I, Overlords RPN welcome our new . . . .
Your hair look like poop, Bob! - Wanker.
Looks like you depend on your TI-89 a bit too much.
(b^x)^y = b^(xy)
When you buy a calculator, you aren't just buying a generic handheld computer, you are buying a mathematical software package. I don't know about TI, but HP has invested many years of effort by HP mathematicians and engineers in designing, implementing and testing the software that runs on their calculators. That is what is valuable, not the near-obsolete hardware that the calculator is built from.
Mea navis aericumbens anguillis abundat