[HN Gopher] The R47: A new physical RPN calculator
___________________________________________________________________
The R47: A new physical RPN calculator
Author : dm319
Score : 154 points
Date : 2025-11-07 08:00 UTC (4 days ago)
(HTM) web link (www.swissmicros.com)
(TXT) w3m dump (www.swissmicros.com)
| dm319 wrote:
| This is a project to imagine what HP would have made today had
| they still been making calculators. It is unusual for a newly
| designed RPN calculator to be released, although there have been
| several re-releases of older HP models, such as the HP-15ce,
| HP-16c, and a series of calculators made by Swissmicros - DM-15L,
| DM-42, DM-32, but all based on designs dating back 30-50 years.
|
| The R47 has been many years in the making and is a small open
| source project which has collaborated with the Swiss manufacturer
| of calculators, SwissMicros. It has a superset of functions over
| older HP models and many more too, including complex solve,
| default 34 digit decimal precision, 1000 digit integers,
| graphing, extensive complex support, etc and is substantially
| customisable.
|
| I have no affiliation with the project, but excited that there is
| a new RPN machine commercially available.
|
| [0] https://youtu.be/5A-pmjawJg8?si=11Ehf5SnzkZF79-e
| TheOtherHobbes wrote:
| I don't think HP would be making something like this.
|
| The original calculators, from the discrete HP9100A onwards,
| pushed tech to its limits.
|
| The HP65 (1975) was a jaw-dropping masterpiece. When most
| calculators were four function, and scientific calculators were
| still exotic, a pocket-sized programmable calculator with a
| magnetic card reader was beyond the imagination of most
| engineers, never mind most users.
|
| This is more of a nostalgic tribute act. It's nice it exists.
| But it's looking backwards, not forwards.
| macmac wrote:
| Already Out of Stock. I want one :-(
| dm319 wrote:
| The release day is meant to be today, the out-of-stock just
| means they haven't opened yet.
|
| They've asked people to purchase a voucher on the C47/R47 site
| for an early-bird discount which will send some money towards
| the developers. This voucher can then be used to get the
| calculator once SwissMicros take bookings. The link is at the
| bottom of the Swissmicros page.
| globular-toast wrote:
| I really want one, but 250 credits is quite a bit too much. Even
| at 100 credits I'd be questioning my sanity, to be honest.
| NewsaHackO wrote:
| Its ~300 USD. I wonder who the target audience is.
| ch_123 wrote:
| There is a community of folks who are really into this
| firmware, and a lot of those people buy SwissMicros other
| models of calculators, (e.g. DM42 or DM32) and put keyboard
| stickers on it. This allows them to buy the model with the
| correct key legends up front.
|
| The low volume and the relatively high build quality involved
| pushes the prices up.
| NewsaHackO wrote:
| I can see that. The build quality and screen both seem to
| be very high end.
| fm2606 wrote:
| I still have my HP 48G and love it. I don't use it much and take
| the batteries out so they don't corrode in the case.
|
| Every time I use for more than a couple of calculations I think
| how much I prefer a RPN calculator.
| ch_123 wrote:
| The DB48X project created a HP48G/HP50G style firmware for
| SwissMicros calculators.
|
| https://github.com/c3d/db48x
| natas wrote:
| The db48x/db50x project seems to be more promising than
| C47/R47; although, I wish Swissmicros could produce a db50x
| version with the right layout (no stickies)
| abawany wrote:
| Mine is unfortunately now dead - the display has gone dark even
| though the device is functional. At some point I'll have to
| look into a repair or replace with something from SwissMicro.
| pavon wrote:
| Ooh, I'm going to have to download the emulator tonight and try
| this out. The swiss micro and 47calc sites both say "display with
| 4 stack levels", but I can't figure out if that is also the size
| of the logical stack.
|
| The shift key on my HP28C died last year. I never used the
| advanced features (eg the entire left-hand keypad), but loved its
| effectively infinite stack, and haven't been able to go back to
| an HP42, HP35s or the like since.
|
| I'm now using Plus42 on my phone with the big stack option, but
| would love to have a physical calculator again.
| hamburglar wrote:
| "Display with 4 stack levels" would accurately describe the hp
| 48 series, which had a screen that could _show_ the top 4
| things on the stack, but the stack itself had much larger
| capacity (maybe limited by memory? I can't remember).
| PopePompus wrote:
| There was a time when I would have salivated over this. But now I
| can run iPython on my phone, and have numpy, sympi, scipy,
| astropy and countless other packages. Physical keyboards are
| great for calculators - much better than virtual keyboards on
| phones. But the keyboard advantage seems to me most valuable for
| quick calculations, not elaborate things like this calculator
| offers. If I'm going to do matrix calculations, I want to be able
| to put the data into a file with a real, and familiar, editor. I
| want to be able to grab tables of data from the web. If I make a
| plot, I want to be able to save it to a PNG file. I want a high
| resolution color display. A phone running iPython/Python seems
| much better to me, especially since almost everyone who would
| want to do what this calculator does already has a smartphone.
| Also, I can ssh into my phone and interact with it using my
| desktop computer's keyboard and monitor, eliminating the phone
| keyboard limitations when a full sized computer is nearby.
| grugagag wrote:
| True but a dedicated device has its own advantages (and
| disadvantages). Despite high availability I dislike spending
| too much time on my phone beside quick uses.
| wslh wrote:
| Yes, the "On/Off" button is instant and goes directly to the
| point/prompt.
| ct0 wrote:
| What IDE do you use? this functionality sounds great.
| PopePompus wrote:
| I use Android phones, and there are at least two ways to get
| iPython going on an Android phone.
|
| The first is Termux, which provides a gnu userspace atop the
| Android kernel. This app is pretty old, and well-tested.
| There is an active and helpful Termux community. But it has
| some downsides: 1) The version of Termux in the Google Play
| Store is not the preferred and maintained version, although
| the Play Store version does work. The preferred version is in
| F-Droid, but the future of F-Droid itself is uncertain in the
| light of recent Google policy decisions. 2) Termux does not
| have access to directories such as /proc, /sys etc, which
| prevents some gnu/Linux utilities from working and 3) The
| Termux filesystem layout is very non-standard, so unless a
| program has been packaged explicitly for Termux, installation
| will probably be messy. I was able to get most, but not all
| of the Python packages I use frequently, to run within
| Termux. I could not get astropy to work, for example. Termux
| has nice usability features like pinch-to-zoom to change the
| font size. Termux requests a wakelock, and if you grant the
| wakelock then the OS will not throttle the app when your
| phone is locked.
|
| The other option is the relatively recently added "terminal"
| app. terminal runs a plain-vanilla Debian Linux OS within a
| VM. Its file system is laid out exactly as you would expect,
| so if you want to get iPython and lots of libraries, you can
| just run the Anaconda Python installation script, and it will
| run unmodified with no errors. Nice! You can also install
| other nice desktop-style apps like VeraCrypt. There are a few
| downsides: 1) The OS will throttle the app, and occasionally
| kill the app, when the app is not actively being used
| interactively. 2) I have found no way to change the tiny
| font. 3) It's a Google app, so it might disappear for no good
| reason, as so many Google products do.
|
| Both of these options work especially nicely on a foldable
| phone, because then the tiny phone keyboard is much less of
| an issue. A foldable phone plus the terminal app really is a
| pocket Linux computer.
| scandals wrote:
| I can't seem to find a Terminal app produced by Google LLC
| in Play store. Could you share the playstore link?
| PopePompus wrote:
| It's actually not in the app store, and it may only be
| available on Pixel phones. You get the app not by
| downloading it from anywhere, you just enable "developer
| mode" in the system settings, and the app magically
| appears in your app menu (the full menu, not on any home
| screen by default). There is a subreddit dedicated to
| this app ( https://www.reddit.com/r/androidterminal/ ).
|
| I've never used a Samsung phone, but I think their DeX
| environment might allow you to do the same things that
| the "terminal" app supplies.
|
| If you can't get either of the above to work, give Termux
| a try. It's not full gnu/Linux, but it's pretty close.
| Elfener wrote:
| Same. Although I have a few physical calculators, I rarely use
| them, because although for a simple calculation they're faster,
| when I'm already at a computer/phone, using that is faster, and
| when I want to do anything involving programming an actual
| programming langugage is better.
| bombcar wrote:
| Physical devices can be great where you have dust and water
| issues that can make a phone nearly impossible to use.
|
| Of course, then a $5 calculator may serve you better ...
| ghaff wrote:
| My HP41CV died after a few decades and a full repair didn't
| seem feasible. The Swiss Micro seemed tempting but I honestly
| really wouldn't use it.
| Baeocystin wrote:
| I don't really disagree with anything you've said, but I still
| feel a warm spot in my heart from projects like this. I still
| have (and use!) my HP48SX from my high school days, and it
| still works like it always has. There is something to be said
| for a device's limitations, and I mean that honestly. It's very
| powerful for what it is, but its processing limitations keeps
| me from overextending, which is something very easy to do with
| the pocket supercomputers we've all gotten used to carrying
| around over the previous decade. (And its keys are simply a
| delight to press compared to even the best glass touchscreen.)
| 0xTJ wrote:
| Even with almost all of my work done on a computer, with
| Python, MATLAB, etc. available in a few keypresses, I still
| keep a calculator on hand. I haven't come across a desktop
| calculator (including direct 1:1 software recreations of
| classic calculators) that's quite as user-friendly and
| efficient as grabbing a scientific calculator off my desk and
| typing in there.
|
| There are just some user interface advantages for me in having
| a physical calculator. The only thing stopping me from buying
| this is the price tag.
| jwr wrote:
| A physical calculator is a tool, so is your python interpreter,
| but they are different tools for different purposes.
|
| Mathematica does everything your python interpreter does and
| more -- but that doesn't mean python becomes useless because of
| that. It's good for certain things, while Mathematica is good
| for other things.
|
| Similarly with calculators (especially HP calculators), which
| have become a bit of a lost art (an elegant weapon for a more
| civilized age). I use them all the time when doing any kind of
| engineering or hobby work. Good luck using your computer with
| python one-handed in a workshop next to a CNC.
|
| One thing I do agree with is that plotting functions or working
| with larger matrices on calculators makes little sense.
| anthk wrote:
| GNU Maxima it's the best of both grounds.
| anthk wrote:
| Any netbook it's far better than a smartphone for input.
| drob518 wrote:
| I still miss my 15C.
| mprovost wrote:
| There's a really good emulator for the iPhone! Back when I
| bought it, it came from HP themselves, but a few years ago they
| sold it to another company which actually maintains it. They
| just released a major new version a few weeks ago.
| hughw wrote:
| Yes, the new version is really nice now in portrait mode.
| Nice app. Now if only we could have tactile buttons...
| sizzzzlerz wrote:
| I have that and do like it even though it lacks that HP
| tactile feel.
| fmajid wrote:
| I still have mine from 1987. You can still buy the HP-15C
| Collector's Edition new, but it isn't as good as the originals
| with their perfect keyboards and the silicon on sapphire
| technology that gave them their incredible battery life. The
| SwissMicros DM-15L is also a worthwhile substitute.
| Hackbraten wrote:
| > The SwissMicros DM-15L is also a worthwhile substitute.
|
| I got my DM16L two weeks ago and I love it to bits!
|
| They even upgraded it to USB-C (even though the product
| description still says Mini USB), which was a pleasant
| surprise. I only just got into RPN calculators (and
| programmable calculators in the first place) a month ago,
| loving it so far.
| tgv wrote:
| I got the HP15C Collector's Edition, because I always lusted
| after those HP calcs, and never could afford one. People in
| this thread asking: why? Well, many of the calculators on
| screen are simply worse, or copies of decent calculators but
| you have to press every button with the freaking mouse. A
| dedicated calculator feels nicer. Copy&paste is nice with an
| on-screen calc, I admit.
|
| I do have a few other calculators as well, so I'm definitely
| biased.
| dripton wrote:
| Cool. I used an HP48SX in college, and when it finally died about
| 20 years later, bought 2 HP48Gs so I'd have a Lifetime Supply. (1
| is on my desk, 1 is still in the box.) But I confess that hardly
| ever use my real HP48G anymore, because I have the Droid48
| Android app, and the 99% perfect calculator that's always at hand
| is better than the 100% perfect calculator that's on a shelf way
| over there, most of the time.
|
| So I doubt I'll buy this one, even though I'm happy someone made
| it.
| _fat_santa wrote:
| Honest question but who would need this these days? Would this
| calculator still be useful for professors/mathematicians/etc or
| is this more for HP calculator enthusiasts?
| _trampeltier wrote:
| I work in industry automation and use for every day calculation
| mostly my HP 35s, even I also have a HP 50g under my desk and
| more than a PC on my desk.
|
| It's just for me the most easy way to calculate things with
| current and power for everyday use.
|
| And .. even the basic Windows calc app is so slow to start, I
| already finished until the app started.
| aidenn0 wrote:
| I have a 35s as well; I was made fun of for using one (you
| know you're sitting at a calculator that is 1000s of time
| more powerful right?). I still use it.
| _trampeltier wrote:
| A F1 car has more Hp than any tractor and is still useless
| for any farmer.
| auxym wrote:
| Just as a fun fact, some of the largest tractors made
| these days actually rival F1 cars in horsepower output.
| John Deere 9RX goes up to 913 HP for example.
| bradfa wrote:
| My HP 35s sits between the 2 halves of my split keyboard. I
| use it multiple times per day. It's just faster for quick
| calculations as the UI is very well done and it turns on
| instantly.
| hughw wrote:
| I bought a 35s and found the ergonomics not as good as my
| old, dead 11C. So I bought an antique 15C on eBay, and it
| sits right by my keyboard all day.
|
| I'll use the built in calc in macOS Spotlight for many
| things, but plenty of times each day I use the HP. Example:
| yesterday I calculated an angle in degrees by reading off
| approximate x, y coordinates from a graph on my screen.
| Swapping windows to a calculator app, repositioning them to
| see both at the same time, just too fiddly, and clicking the
| calc app moves the cursor so I have to remember the numbers
| as I switch context.. The physical HP in front of me leaves
| my screen undisturbed. Easy.
| kabdib wrote:
| I use an HP-16 (the SwissMicros version, my originals are in
| boxes) and a 35s pretty much every day (these days, I'm writing
| firmware).
| antod wrote:
| Good question. I still use an HP42S these days, but it's an app
| on my phone or desktop not a separate device. Replacing
| batteries was a big pain on the original.
| DanTheManPR wrote:
| It's probably not a necessity - I'm sure I could adapt to just
| using my smartphone if I put the time into learning some of the
| math apps. I still use my ti-89 for everyday calculations. It's
| a handy device; more portable than a laptop, and better UI than
| a smartphone. I don't deny myself from using a tool I like.
| kaladin-jasnah wrote:
| This sort of reminds me of the Numworks, except this feels a bit
| more artisan (and expensive).
|
| In high school, my friends got onto the Numworks bandwagon, and
| we even used them on the SATs and AP tests (they were explicitly
| allowed). To be fair, this is before Numworks locked down their
| calculators and the alternative firmwares (Omega) died off, but
| maybe there are jailbreaks now and things are as they were
| before.
| Elfener wrote:
| > except this feels a bit more artisan
|
| The difference (as far as I know) is that Numworks (and Casio,
| etc.) are mainly used by students, while SwissMicros (and HP)
| are used for very quick problem-solving on the job.
| 7thaccount wrote:
| Also any older folks who grew up with HP calculators and
| prefer RPN over the newer calculators.
|
| There was a time when RPN was waaay better than the TI and
| other competition, but in my mind that time is now past us. I
| can use both designs well and will take a TI-89 over a Swiss
| Micros (mind you I own several) almost any day as it is more
| straightforward. That's my opinion anyway. This improvement
| over the DM42 is pretty cool though.
|
| Another Swiss Micros use is for people who work in a lab with
| gloves and can use a calculator better than a phone.
| outside1234 wrote:
| I still have my HP-42S 30 years after I finished engineering in
| university. Just an awesome calculator that still has that
| awesome tactile button feel.
| speedgoose wrote:
| I think I will stick with a TI-89. No RPN, but that's not
| necessarily a problem. More importantly, it has a CAS (Computer
| Algebra System). I wonder why CAS aren't more common on such
| calculators. The technology exists since decades and it's great.
| I know it's not allowed in some school exams, but calculators
| already have exam modes.
| Jach wrote:
| Yeah I won't give a serious thought to anything that doesn't
| have full symbolic support. I gave my nephew-in-law my old
| TI-89 Titanium last year, he was entering 8th grade and I got
| it midway through 9th grade and it served me well all the way
| through my CE undergrad. Arithmetic, trig, statistics, basic
| calculus, differential equations, laplace transforms, vector
| calculus, it handled so much, and it was easy to use TI Basic
| to add new functionality/shortcuts... Prior to that I was happy
| with a cheap non-graphing scientific calculator (I think it was
| a Sharp EL-531WBBK Translucent Blue). It was fine for algebra,
| trig, geometry, and pre-calc science courses.
|
| My dad has an HP-15C that I've always thought was cool but I
| never really liked to use it for anything. This new calculator
| is also really cool but I can't imagine ever owning one. I
| don't need to do much calculation anymore anyway so it's not
| like I need any calculator at all (hence giving away my old
| calc). I'm also usually at my PC, or a laptop, or I can ssh to
| my home system with my phone (if the phone's basic calc app is
| insufficient). For simple calculations I've most commonly used
| a Python repl since like 2007, but for anything more advanced
| these days I'd pull out one of the PC programs I was exposed to
| in the later parts of college (e.g. matlab or octave+symbolic
| and other packages, or maxima). But I also have used Python +
| libraries or Lisp + libraries, and would like to someday redo
| my Stats education with R. Hand calculators just seem really
| antiquated to me now.
| kstrauser wrote:
| Is this the DM42n hardware with the R47 firmware preloaded? It
| looks identical, except for the colors of some of the keys, and I
| wouldn't think they'd have a separate hardware pipeline for it. I
| could be wrong, though! If someone were to obsess over their gear
| and tweak it until it was just so, this would be the company to
| do it.
| pauli5 wrote:
| Yes, it's the DM42n hardware underneath. The keyboard and
| overlay are different and the firmware is written from scratch
| using the WP 34S mathematics code. This has a lot more
| functionality than the DM42n does.
| cameldrv wrote:
| I'm sort of surprised by SwissMicros focus on the 42. I have a
| 42S and a 48GX and the 48GX is IMO far superior in almost every
| way. My only complaint is that the UI can be sluggish in places,
| but with a modern CPU this would completely go away, and it does
| on the 49, which I also have, but unfortunately its screen died
| and the keyboard stinks. The 48GX was the last model I have where
| they actually built it with some quality.
| cmxch wrote:
| Still got my 48GX, 49G, 19BII and 28S. The 49G is the only that
| is unusable (rubber buttons? Really?).
|
| 49G aside, they all are good enough for use although probably
| no longer usable in some of their intended uses (re: any formal
| tests that would allow them?).
| 7thaccount wrote:
| I have a few Swiss Micros, but rarely use them. Beautiful devices
| though. Built to last forever.
| shtzvhdx wrote:
| Terrible keyboards though. At least compared to my beloved 48s
| and 28.
|
| How Id love for SM to do a straight 48G with more memory and a
| good keyboard. (But keys are hard to do)
| 7thaccount wrote:
| My DM42 feels great. I haven't touched a 48g in ages though,
| so can't compare.
| _verandaguy wrote:
| Maybe it's a generational thing -- I haven't had to use a
| standalone calculator in my professional life -- but what's the
| benefit of using RPN as opposed to the more common infix
| notation?
|
| Beyond that... do RPN calculators like these usually include the
| option to use infix notation?
| xyzzy_plugh wrote:
| It eliminates the need for parentheses and operator precedence,
| which is honestly nearly half of the character count of my
| usual infix math. You can just keep performing new calculations
| and then later on decide how you want to combine them. It's
| pretty great.
| TheJoeMan wrote:
| The iPhone calculator, for example, only recently added
| parenthesis. However, with prefix notation you have to plan out
| your open parenthesis, and if you forgot one you have to back
| up. With postfix, the parenthesis are implicit. Which is
| faster? "2 2 + 2 x" or "2 + 2 = x 2 =" for 2(2+2)
| electroly wrote:
| On a basic four-function calculator, you can do "2 + 2 x 2 ="
| to get 8 without the extra = in the middle. RPN really shines
| when you use the stack for real. "(2 + 3) x (4 + 5)" is "2 3
| + 4 5 + x" in RPN, but on a four-function this requires the
| stateful memory buttons and gets out of control fast. You may
| need to spill out to pen-and-paper with a four-function
| calculator, but you never need that with RPN. I'm less
| certain that the comparison works out in RPN's favor if you
| have a calculator with parentheses--where are you getting the
| complex expression that you're entering? If it's on paper,
| then it's already in infix notation and you had to mentally
| convert it to RPN inside-out. Entering the infix notation may
| be more keystrokes but likely less mental effort because it's
| more of a direct transcription. I taught a sibling how to use
| an HP-12C and I don't think they're ever gaining that time
| back in efficiency.
| heisenbit wrote:
| Way back around '84 in the military I was doing the artillery
| survey calculations for the Lance (potentially nuclear)
| missile. We had to store first the program into the volatile
| hp memory, run check calculations before doing the real
| calculations. I always found the calculations very efficient
| - they had to be as they had to be done within certain time
| limits (and independently checked). It was a strange feeling
| thinking about doing the calculations under high pressure and
| what the stakes were if you would get the coordinates or
| directions wrong in case it would be used.
| stackghost wrote:
| I have an HP50G that lets you switch to infix notation, but for
| most operations RPN is faster due to fewer keystrokes.
|
| Like many others here, I rarely use my calculator any more. My
| phone is just so much more powerful with a lisp REPL and
| python.
|
| This is cool technology, though.
| rickz0rz wrote:
| Looks like it might be the same Sharp memory LCD screen that's on
| the Playdate? 400x240 monochrome LCD display, roughly 2.6-2.7"
| diagonally?
| a3c9 wrote:
| I think it's likely - from what I can tell only Sharp makes
| these displays. I've been looking for displays like these (no
| backlight, fast refresh) for a project and all I could find was
| the Adafruit breakout of that one.
| GloriousKoji wrote:
| Am I the only one who dislikes the CR2032 that all the RPN
| calculators need?
| antod wrote:
| No, although my old one (HP42S) used 3 of the smaller stubbier
| batteries.
| sizzzzlerz wrote:
| I had a 48C that fed on those batteries. They lasted forever.
| I had to retire mine when the battery door broke and the
| batteries wouldn't stay in. It was a great calculator from
| HP's heyday.
| kstrauser wrote:
| How come? I admit I've never given it any thought. What do you
| dislike about them?
| creer wrote:
| > Processor ultra-low-power ARM(r) Cortex-M33(r), at max. 160 MHz
|
| > Battery type 1 x CR2032 3V lithium coin cell
|
| Very nice. Impressive.
| crims0n wrote:
| I have an embarrassing question... math has always interested me
| but by luck and circumstance I have had a pretty successful
| career without needing anything beyond college Algebra. Can
| anyone recommend a curriculum that a busy adult may be able to
| follow in their spare time? I just want to fill in blanks and
| explore what is possible.
| jerkstate wrote:
| mathacademy.com is pretty awesome IMO. one hint: don't take
| notes/allow yourself to refer to notes during quizzes and
| reviews, the point is to be able to recall using just your
| brain, even if your progress is much slower that way, you'll
| learn a lot better.
| kstrauser wrote:
| Many studies concur that the act of taking notes dramatically
| improves your ability to remember what you wrote, even if you
| never look at the notes again. You generally don't have time
| to transcribe a lecture like a stenographer would, so note
| taking requires you to understand the material enough to
| summarize it and describe it in your own words.
|
| Don't rely on your notes come quiz time, if you can get away
| with it, but by all means do take them during the learning
| process. And in the real world, you're allowed to refer back
| to your notes as often as you want to.
| pavel_lishin wrote:
| I don't think that's embarassing.
|
| I like solving math puzzles, and I'm often realizing that I'm
| missing something I've forgotten since middle school or high
| school - some formula that I know exists that would make a
| problem trivial. I'd like to re-learn that stuff, especially as
| my kiddo starts advancing in math classes.
| JKCalhoun wrote:
| For me, I set out to write a flight simulator from scratch
| following a book [1]. I learned a lot of linear algebra that
| way. Such that when I later took Calculus III in college (it
| was linear algebra) I aced the class.
|
| (Also, reinforced what I remembered from Trig, I finally fully
| grokked it. Except for trig identities, ha ha.)
|
| The book was targeting DOS and C++. I wrote it in C for the
| Macintosh. (That required that I figured out what was going
| on.)
|
| Go write one in JavaScript using an HTML5 canvas as your
| buffer. (I made a quick pass at doing something similar [2] --
| but do it on your own, don't follow my link below or look for
| the sources for Phosphor3D on GitHub.)
|
| [1] https://archive.org/details/build-your-own-flight-sim-in-
| c-d...
|
| [2] https://engineersneedart.com/Phosphor3DTest/
| mintplant wrote:
| Super cool! But I so rarely reach for the physical calculators I
| already have these days. Any recommendations on RPN calculators
| for Windows or Android? The one I've got on my phone right now
| has some little quirks that bug me.
| manithree wrote:
| Which one do you have on your phone? Plus42 for Android has
| been mentioned. I like Droid 48 (also Android).
| bolangi wrote:
| I use one called 48sx, however, I've only ever used +-*/.
| Clicky physical buttons are much better of course. An
| accountant I worked with years ago had one with a printer,
| which meant she had a paper record and could verify that the
| entries were correct.
| jll29 wrote:
| I appreciate the quality of the engineering and design, and that
| the hardware is open to being tinkered with by means of firmware
| update. The price seems fair for what is offered, and the device
| looks like it would be very useful for anyone who doesn't have
| any computer at hand or readily available. Kudos to the project
| team!
|
| But it's unlikely that I buy one because (1) I tend to be close
| to computers most of the time, (2) my favorite "HP calculator" is
| the HP9000/715 due to its sizeable HIL keyboard, its 21" CRT
| color screen, and its support for HP-UX, pun intended; and (3)
| most of the mathematics I need beyond paper, pen and blackboard
| can best be done in a Python Jupyter Notebook (statistics) or
| Mathematica (symbolic derivations).
| spankibalt wrote:
| Release a souped-up all-metal HP 200LX and I'm gonna be a
| customer (x86 with AAA batteries, no ARM workaround).
| idatum wrote:
| I'd love to see a non-programmable version. If I recall it would
| be something like the HP 10C. It's because I just want the RPN
| part along with math functions.
|
| A good example: Taking your FCC ham license exam does not permit
| use of your phone or a programmable calculator. They would have
| allowed me to use it.
|
| I had practiced for the exams with my old HP 11C. It was jarring
| to have to switch to a TI calculator during the test.
| 7thaccount wrote:
| Swiss Micros makes several reproductions of old HP calculators
| such as the 11c, 12c, 15c ...etc. I know the 15c has keystroke
| macros, but not sure about the 12c.
|
| Edit: it looks like you're right and they're all programmable.
| My mistake.
| clickety_clack wrote:
| The only calculator I still use is a business one (and these guys
| sell those too it seems!). It's super handy for figuring out
| interest rate stuff, growth rate stuff etc. for anything simpler
| or more complex, it's just easier to use a phone or more
| checkable to use a laptop.
| lisbbb wrote:
| My college girlfriend had an HP RPN calculator of some kind
| (42s?) that was non-graphing. She loved the calculator and never
| wanted the bulkier 48sx graphing one her Dad bought her, which is
| how I ended up with it. I kept it after the breakup and she got a
| Sony boombox. The HP still works 31 years later.
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