UPDATE: It can display more than 11 digits, press and hold Shift SHOW. Actual forensics result: pbs.twimg.com/media/DuqjX9oUUAAP-HO.jpg

At the risk of giving away my age, my first-year chemistry Prof said, "A calculator is a device by which a freshman can determine the wrong answer to eight significant digits".

I wish I was as enthusiastic with my entire life as this man is with his calculator

This is definitely a "right to repair" friendly device: Open source firmware, off the shelf microprocessor and even instructions on how to take it apart written on the PCB!

David: *opens the package excitedly* My better half: "Honey, what are those noises, what are you watching?!"

Rpn calculators was always fun to loan out to a unsuspecting student who forget their calculator. HP for the win!

I have this calculator on my desk now, and I'm yelling things at the screen. :D You can see the full precision with "show" (second function of the decimal key). You can also subtract 9 from the result of the calculator forensics result to see the leftovers. :) You can upgrade the whole thing online, of course... but even better, you can download programs and save them. Hell, you can even change the pictures that come up when the calculator is off. I've uploaded a bunch of NASA-themed pictures on the DM42 forums. Too bad I only use it to convert between hex, decimal, and binary these days. Oh well. At least I can convert in STYLE!

7:51 - They need the *black solder mask* since you can see the PCB through the openings for the keys. One time when using a black solder mask is actually the right choice!

As a mechanical engineer I accumulated a lot of old hp calculators over the years. I have hp 41CV, 15C, 28S, 20S, 48G, 49g+ calculators. I've also got an hp calculator IR thermal printer and paper. Plus a few more older hp calculators I can't remember right now. The older models with the "rocker" style keys were the best in my opinion. You could fly through a long calculation by just tapping the keys without having to watch the display to make sure you didn't get multiple digits with a single key press. Ti calculators with their "floating" keys had a bad habit of giving you a screen full of 7's or some other digit with a single key press. This was a problem Ti calculators had especially when they got older. The original hp "rocker" top-hinged keys with tactile feedback were great. Unfortunately, later and current hp calculator keys are ok but not as good as the original keys. I also had a Ti 59 with magnetic card read/writer and cradle with thermal printer with two optional math modules. I gave it away to one of our drafters back in the late 80s.

I am still using an HP48 up to this day. I have other HPs and TIs as well. But that one is my favorite by far. If SwissMicros ever builds a clone of the 48, I will buy it.

Very nice, my favorite calculator was the HP28S, I also like the HP48GX which was more capable but the 28S will always have a special place in my heart.

DM42 stands for *D* igital *M* ultimeter with the answer to life, universe and everything.

@1:30 - Had to turn it down... sounded like i was watching a porn xD :) :P :D

Thanks for this. In college I started with an HP21, Currently use the HP42S. HP makes the best calculators. Go RPN.

5 years ago after watching this video I decided to buy the DM42 and never regretted it. Great device, also have the DM15.

I've loved my HP42s for the last 22 years. Gonna get myself one of these for everyday use though, I think I'll look at a landscape one as well. Thanks for making this video.

Did the sin->cos->tan trick on my TI-82 and it returned a 8,99999997. My disappointment is immeasurable and my day is ruined.

I used HP-48sx during my university time around 1993 still have it working, and lovin' it...

Love how you turn into golem around calculators… "my precious"

Still using my HP 32S I bought new back in 1988. The keys are just as wonderfully tactile as they were 30 years ago!

That's awesome! My first calc was a TI SR-10 (yeah, I know... sacrilege to the RPN fans). It only had add, sub, mult, div, square, square root and reciprocal.... and it cost $150. But it was worth it. I sold it after a few years and purchased the programmable TI-55. And believe it or not, I still have it. Great video. Thanks for sharing. :)

HP 41 with all the ROM packs. I have land surveying, cut & fill. My father was a civil engineer & hydrologist. Now he is a hydraul-o-ghost. RIP Dad. His ashes went into some of the rivers he did work on. The Arkansas River, The Rio Grande, The Pecos, The Mississippi, The Salt & Gila which flow into The Colorado. The Gunnison which flows into The Colorado. And just for fun, Paradox Canyon. What is the paradox of Paradox Canyon? The river flows out of both ends of the canyon. It's a great way to get lost.

I’ve done it, I’ve reached the end of the internet

I abolutely understand and love your enthusiasm.

Pff my Nokia 900 has *arbitrary precision* (until you run out of heap space) with GNU MPL and that suckers 10 years old. I had a crappy TI83, then an awesome (nonplatinum!) TI89, but often yanked my fathers HP48. The 15, 42 and 48s and the last run of 50s were absolute killers. HP Laserjet III's (still running, half a million page count!), the 3458 8 1/2 digit DMM, man oh man. Fiorina absolutely gutted that company taking it from 50 years of rock solid engineering into just a tragic shell, just so she could see a quarterly share price bump (that'd last half a year before investors realize they have no good products or engineering left, dumping the market cap to 1/10th the original value) and pay herself a performance bonus.

I still have my HP 11C which I got 32 years ago from my father for my birthday. It still works perfectly, and I use it almost every day. I love it! It's good to see that SwissMicros carries on the legacy of these great calculators.

Yaaaas! Still have an HP-42s in my desk drawer! And my go-to calc app on the phone is Free42.

My first calculator was an HP-45. I spent about $400 on it, which in 1973 was real money. As a result, I can only use RPN calculators. I never get the right answers with an algebraic calculator. Now, I use RealCalc on my Android phone which has an RPN setting and resembles an HP calculator.

I still have dad's HP67 in great shape!!

I wish my lecturers could talk with this much passion.

I'm married with my HP48G since 1994 ...

That is the nicest modern product I seen, thanks for sharing.

Me: "Is that an e-ink display?" EEV: "That's an e-ink display!"

Joke of the era: RPN has no equals.

Tststs... Cheating on the customs declaration... 22CHF :p

with all the companies these days that clearly spend all their money making their website look pretty rather than manufacturing products from quality materials it's nice to see someone doing the exact opposite

I'm glad to see reproductions of these old HP classics. It brings back memories. In 1973, my freshman year at MTU, we were taught how to use a slide rule. 4-function calculators like the TI SR-10 had become popular but we were not allowed to use them on tests, only slide rules were allowed. The next year the engineering departments finally saw the future and allowed calculators on tests but the new HP-45, HP's first scientific calculator, was expensive, something like $400 back then. My roommate was one of the first to buy one but I couldn't afford the price so opted for an SR-10 which at the time cost a whopping $99. I didn't like it much so didn't cry too hard when I lost it one day as it gave me a chance to plunk down the dough for a new HP 25 Programmable Scientific calculator which I still own. I loved the thing and used it throughout my early career through several sets of home-repaired nicad battery packs, but when the keyboard started acting flaky I replaced it with an HP 32S II. Great machine, it has served me well the past 20 years or so. I use calculators only occasionally now but I find I can't use the algebraics for scientific functions anymore without reteaching myself basic formula notation first. The HPs had brought out the elitist in me. Real Engineers use RPN, algebraics are only for engineer wannabees!

Are the white labels on the buttons just printed or are they laser etched into the button? As a heavy calc user I hate printed buttons because the printing wears out or rubs away after months of use... I could not find anything on their website to indicate how they label the buttons...

You show all 34 digits by using yellow shift and then select "show"...

In the early '80s I had a HP41CV during my EEC course at Meadowbank. Once I got used to RPN it was a great programmable calculator. It came with a sizeable set of manuals. It finally died only about five years ago when a Duracrap cell leaked and destroyed the board and the pads on the back of the LCD.

8:43 - they know their customers! Telling how to properly disassemble the unit.

The HP 4x calculators were the last solid military grade quality product that left Hewlett-Packard factory gates. Ever saw the synthetic programming package? Awesome. They make plastic toys since these glory days.

HP also used flat flex battery contacts in some of their calculators. I used to have a 41CX which had those.

Love these videos! I still use my HP15C that I got new back in the 80's. It's still working perfectly. :)

I have 3 HP 32S's 1 heavily used since I bought it in '88 and two brand new in the boxs. One is the 50th anniversary edition. The 32S or the 15C are my go to every day calcs. I'll be dead before I need another.

Oooh. The HP41C was my college calculator. I had the clock/timer module for it which was really cool. It had very powerful time/date functions in addition to all the math stuff. This really brings back memories! I swore by that calculator, as well as the HP16C which I used almost exclusively (invaluable as an assembly/machine-language programmer since everything we did was in HEX). The real question is whether this knock-off is using base-10 or base-2 floating point. I seem to recall that all the HP calculators used base-10 floating point (BCD) storage formats, whereas all modern computers use Base-2 mantissa and exponent formats. It was a big deal, because you can't exactly represent base-10 fractional values using base-2 mantissas. I'm guessing this reproduction doesn't go that far. These days, yah... I use the Casio fx-115es. Quite a few years old itself. But I really hate it because it doesn't have a permanent ENG mode. The ENG button isn't a 'sticky' mode. Drives me nuts. I just want the blasted thing to always display results in engineering notation, period. -Matt

Me to YT recommendations: am I a joke to you ? After a few minutes: cant stop watching

nitpicking... at 2:59 the binary floating point 128-bit box is highlighted, but per the website the calculator uses a decimal floating point 128-bit library- which makes sense for a calculator application. Also, that chip is a cortex-M4 which has 32-bit binary float hardware. I wonder if that gets any use in the firmware?

This reminded me that I have a HP 41CV in my parts cupboard. Yup, still works :D

"Love a good root" I almost missed that at 15:26. Thanks Rake, for teaching me Australian slang.

Maybe SHIFT+ENTER/ALPHA to insert the A-Z symbols?

My first calculator at university was an HP-11C, then an HP-41CX that I could hookup to the equipment in the lab and run experiments with. I bought the HP-15 LE only to realize it wasn't anything like the original, it bricked itself in no time but the others are still working. The HP Voyager series had the best layout for any calculator. I think I'll get a couple of these DM-15L for myself and my kids.

Aw, man, i've got 48gx, 49g, 49g+, Prime and some others, now i have to get this too...

Dave, the type of guy who makes me waste time and money in calculators I don't need.

I believe the LCD is a Sharp LS027B7DH01.

To access the letters, you press the Yellow button (Referred to as ctrl or 2nd, we will call it ctrl). After pressing the ctrl key, press enter which will enter alpha mode which will let you press buttons to insert letters. You can exit it by doing the same process.

I don't like the filled in zeros either. Unless there will _really_ be confusion with the letter O just use the standard narrower 0.

I had my fair share of being in love with pocket calculators especially when they very expensive and very hard to come by in Brazil... someone would need to bring one from their international travels... even nowadays I still feel kinda mesmerized when I see an HP15 picture even though I have no use whatsoever for such beautiful device.

Nice video; the multi-line e-Ink display is quite an improvement, as well as the mechanical assembly when compared to the crappy HP method where you had to almost destroy the calculator to open it. You miss on the nice tactile feel of the keys, though (and perhaps battery life). IMHO, you need to have quite a lot of burning cash in your pocket to pay that much.

I have had my 42S since 1992(ish). It is the oldest piece of digital technology that I own, and it still works perfectly!

SwissMicros calculators are amazing - I want to get a DM15L someday. It's sad when the highest-quality HP calculators currently available are not made by HP. The display line bug is rather surprising. Maybe they've fixed it, and you're running an older version of the firmware?

The only question is, will this go the route of Numworks? (Try to go for that education market, only to get their firmware closed-sourced for exam compliance)

You're confusing precision with resolution.

So far my favorite calculator would be smartphone or the TI84+CE. For a normal calculator the 84+CE is crazy some of the functions if can do.

If it doesn't use #bignums, like any flavour of Lisp, then it just doesn't cut the mustard as far as precision is concerned.

Remember saving for months to buy a HP42-C. Still have it. And still remember how to force it to double the clockspeed. Has to be the very first overclocking I ever did. Guess it was back in - 87 or so.

I think this is far from the world's most precise calculator, but one without CAS certainly. I used to have a TI Voyage 200 and that thing was much more precise, however it uses a computer algebra system and is capable of exact symbolic calculations.

KZfaq recommended thus channel to me, did not know there was a serious market place for calculators, nice!

With a board like THAT they could make a full custom graphing calculator - or better yet, beat TI at their own game :P

The dotted zeroes add a little flair to the old 5318008

you show all the digits by pressing show, shifted decimal point key.

Awesome. Everyone who has a compatible brain should have one of these. Cheers!

Just googled the DM42...holy crap, that is expensive!

I cant wait for the TI-84 replicas to come out when I am 60 years old. I would die happy if TI-BASIC were the first and last computer programs I wrote.

I'm waiting for the HP-16C replacement - always wanted one. I have originals of many of the other models.

I have the DM16 and it is nothing less than fantastic. With a little programming it is actually also both easy and fun to use.

Show that video to Matt Parker

3:02 You circled the wrong row, the calculator uses decimal128 for legacy (and it has an option for binary64 for speed, while sacrificing program compatibility)

You know... I would like a remake of the TI 83+ that was built as well as you'd expect for a 100 euro machine. The real one, while it is a good calculator, is really built as cheaply as they can get away with... I suspect the cost to manufacture one is not much more than 15 bucks.

I came across a HP-71B , a few weeks back, after a neighbour's wife was clearing all his old stuff from his work days- I was chuffed t bits - it's even got a infra red wand with it too !! and the magnetic card read adopter - What a score !!

The video seems to be unlisted?

3:00 You highlighted the wrong line in the table there (it should be decimal128), although you spoke the correct number of digits and exponent range.

My calculator does double that. Uses a XILINX FPGA

I bought one of the first thousand HP41C in Santa Clara before starting 1st year engineering. It blew my mind with lcd display, alpha numeric capability, memory after turning off power, programming language, expandable etc. The manual was a treat to read. I also got a PPC custom rom which extended functionality and supported micro coding (a hack which allowed low level programming of internal registers to make new characters and all sorts of unintended control of the calculator itself). The PPC club was made up of 41C enthusiasts and even published a newsletter x times a year. Felt like you were in a secret society. Sadly the 41C isn't working but someone built a 41CV android app with the same display and keyboard. Now I can keep a 41C with me all the time.

14:14 "I love a good root" Don't we all!

My dollar store calculator that has been screwed right through the board to the desk , has had all the buttons worn off , the screen is so scratched that it’s barely legible, still works , and has for years. The solar panel actually works and has kept it alive ,

Thats not a knife!

As an HP-41C fan, I'm really looking forward to the DM41X

Wouldn't a calculator with symbolic math and arbitrary precision rationals such as the HP 50g be "the most precise" ? Literally no rounding at all.

The solver function is a perfect feature.

I bet it can show date-time in iso 8601 format, or at least I hope YYYY-MM-DD HH:mm:ss :-)

My HP15 is still going...one of the best calculators I have ever owned. I also had a 41CV (it died a horrible death), and still have a 48GX. I use an HP48 emulator on my phone as well...

>USD 200, that's more than some cheap Android phone. And then even with bugs like no help, only 11 digits displayed, display bugs, and unusable programming interface? No thanks. PS: the forensic test would be more useful with a -9 operation at the end.

Nice but is an HP-48 coming soon? That was my favorite with the added PCMCIA cards for specific functions!

12:54 Well, no, not your imagination - we noticed 10 minutes earlier in the video. Such _obvious_ software bugs being unfixed, along with the missing help files, unusable (?) extra precision, etc., is infuriating. With the shitty build quality (seriously, those buttons will snap sooner or later) and the absurd price tag, I'll stay away from this product. Very disappointing :( I do understand that this is "calculator porn" for many people, and I _love_ its screen, but with 200$ you could get a mid-range Android phone and load the arbitrary-precision GUI calculator of your choice (there are surely dozens, free of charge). More readable, more usable, more powerful, more precise. And more power-hungry :P

FWIW, you can emulate the original “Voyager” HP calculators using Nonpareil. It seems 100% accurate, using their original firmware.

Made me get out my 32S II and teach my 9 year old RPN!

I am still using my HP 32 II. I bought it 91 or so.

I remember a former colleague of mine had an authentic HP35. I was a little afraid to touch it, because I knew it was such an iconic model and I didn't want to break it

OK, that's IT... I'm ordering! SwissMicro picking up where HP left off. 2022 update: I've had my DM42 for a while now and I am very satisfied with it to say the least. I am ordering my second calculator (different model) from SwissMicros in about a week, and my third in two months, fourth in hopefully less than a year...and so on...Thanks EEVblog!