HP-41CX Pocket Computer Hiding as a Calculator - First Look 

When I was a student, one of the advantages of having an RPN calculator was that almost no one ever asked to borrow it. At least, not for a second time.

I bought the HP-11C for my first year of engineering, I quickly learned I should have bought the 15C instead so my second year I bought the HP-41CX. I bought some modules to help with thermo and fluid dynamics and math functions. I used to connect it to the test equipment in the lab and automated taking readings directly. I loved RPN on those calculators and I still use them when I need to get a quick numerical answer. Four of these, along with custom modules from NASA were on the early space shuttles as backups to the onboard shuttle computers. That is the kind of quality I miss. When HP re-launched the HP-15C as a special edition I bought one, it stopped working less than two years later. My 11C and 41CX are still working after almost 40 years.

This brings back fond memories of me learning about programming on a TI-56. I was in the Air Force, in the barracks at Torrejon AB, Spain, and another troop asks me if I'd be interested in buying his programmable calculator. I had no idea what he was talking about, but I went ahead and bought it. That started my life long hobby of computer programming. I had the TI-58 and then later, before I left Active Duty, the TI-59.

HP: High Price; High performance! I have several of the HP-41c family. Still crazy awesome after all these years. It saved my bacon in physics and chemistry classes. Classmates reported me to physics professor. He said, if I could program it to solve for all possible missing variables, then more power to me. I never really programmed it to cheat, but the RPN made it easy for me to perform chained calculations without errors.

I bought my HP-41CX in 1985 and use it as my "daily calculator" ever since. It didn’t fail me once during all those years and is still 100% functioning and all keys are still feeling like (almost) new. HP calculators from the 1970s and 1980s are meant to last forever.

Bought it in the early 80's in engineering school with several modules. Still my daily calculator and 100 % functional.

At 8:50 with the Byte magazine, the name of the company was actually Computer Mail Order, just like it says. That font stylized name was their logo. I bought parts from them in the late '80s, and that is who I always made the check out to (yes most mail order co's took checks back then), and the only name ever printed on the catalogs they sent me.

A company called SwissMicros builds a modern clone of the 41-CX that they call the DM41X. I have one and it is an extremely well designed and built unit. Based on a modern ARM processor emulating an HP-41CX it is the closest thing you can get to the actual HP-41.

As a starving student in the early 1980s, I could never afford an HP-41CX or CV, even though it was the standard calculator in our department-programs saved in the magnetic readers were circulated around to those that had the hardware. I just had a HP-11C that I bought in 1982, which worked well for me; it still runs like a champ now in 2023!

My dad used one in the 80’s with all the accessories when he worked as a surveyor at a construction site of a nuclear power plant in Satsop WA. He bought me the 11 or 12 c (I still have it this day and it works). His had card readers and the printer thing. Way ahead of its time.

I had one of these when I was a young engineer back in the early 80s, along with all of the bits - printer, mag reader, etc. Sadly, it finally failed some years ago and is now long gone. But once you're a RPN guy, you're always a RPN guy. So....I headed over to the Apple App Store, and sure enough the 41CX lives in software as a nice iPhone app. It's once again the only calculator I use.

I remember that era and time frame very well. I was a TI (Texas Instruments) guy, but that 1982 HP 41-cx is the "pinnacle" of what the best calculator could be, was and will be. that is a collectable item, and it represents the finest rendition of any calculator from that time frame. A gemstone - without question. A legend in its own right. In fact, as a calculator that is an astounding 40 years old? It is still not only perfect usable today, but offers amazing functionally and features - even by today's standards. I mean, what else from computer technology can you buy that is 40 years old, and today that stands so tall on its own? Its perfectly able to function in todays world - and stands as perhaps one of the finniest calculators EVER made, let alone from 40 years ago. What a beauty - it simple is!! it does not even look outdated by one day, let alone 40+ years.

The best scientific calculator during its time. It helped me through many tough Engineering courses. It smoked many of its competitors when performing complex calculations during my undergraduate days. Bravo HP-41CX!. Love that RPN.

Oh man - this brings back memories. I remember my uncle having one of these with all the stuff. He had a magnetic stripe reader and did a bunch of programing on it related to his EE consulting. I loved playing with it when I was at his house.

I bought one(~$300) in 1979 or 1980 when I was starting as an upper division physics major at a university in Florida. It was amazing to have so much computational power in my hand. It was especially handy for the numerical analysis subroutines that I programmed into it.

Memory registers aren't associated with keys; they're actually numbered, with registers 00-99 directly accessible. It's just that the top two rows of keys function as shortcut ways to enter 01 through 10 into the prompt. With no memory devoted to programs, there are 319 memory registers, if memory serves, but 100 and up must be addressed indirectly. The price advantage of the CX over the CV is even better than you described, since the CX has both the Time and Extended Functions/Memory modules built in, plus a few other extra functions. It's really fun to see someone discovering what a tremendous leap forward the 41 was - it's like reliving my first moments with my brand-new 41C back in 1979! (I've now got three 41CV's plus my original 41CX).

The space in the box was not for a module, but for a small box that contained the batteries. The fom was a space holder for the card reader that attached on top of the calculator. I got one back in 1986. It costs about $230 at Fedco.

I still have mine, used it through high school, college, and work. RPN was awesome!

A CX had several modules built in. Like the time module. Which is why the stop watch overlay is included. The 41-C was popular. And over time the CV was introduced and then the CX. And legacy compliance to use modules to get CX utility in the CV and C A pristine CX with books is still hundreds of dollars on eBay. I have several. #1 professional calculator in its day. And iPhone emulators are marvelous way to keep the system alive and relevant

My HP41CX still works although I don't use it day to day anymore, I just fire it up every few years N type batteries are expensive The keys are just a delight to experience I have a few plug in modules, Stats, circuit analysis etc The most stupid thing HP ever did was vacate the calculator space From what I remember, I think there was a development group in Melbourne Australia who did some of the internal software design The leather case is quality too Did I mention how great the keyboard is :-) Those keys were better than the TI's too, they would be the only other calculator in a similar class HP told BS in my opinion as to why they dropped using those awesome keys, claiming environmental reasons The best thing about old HP calculators however is not just the build quality, it's RPN (reverse polish notation) !!! RPN is just so intuitive to use and allows one to start almost anywhere in an equation. I think it helped students/users learn how to approach a calculation and understand an equation which modern day in-fix notation calculators do not. I love RPN so much that I use an HP emulator on my phone as my calculator RPN is like the forth programming language, stack based and highly memory efficient I also have a Casio FX 100c as well, programmable in Basic and it still works too but the HP41CX is the device I love

I have my HP 41-CX purchased in 1984 still sitting on my desk. I still use it regularly as I have the muscle memory to be very efficient with it. I do have RPN calculator on my phone but it doesn't hold a candle to the 41cx for large calculations done by hand. At the time I hoped to be able to delay getting a computer- but did get my first PC clone later that year- writing long programs on the 41cx was difficult.

I still have 2 of my Hp 41 calculators, 2 plug in modules and all of the original books, about 5 of them. All in perfect condition.

I have that piece of hardware since 1980 and it is still working, thanks dad!

That one is a very nice calculator. I'm 63, grew up on RPN, my first calculator was a HP-45 and used many of more HP-s during my life including engineering and finance tasks. One tiny comment to your video (thank you for showing the CX): you regret the LCD. Well, LCD was a really big thing back then (and still it is in my opinion). It consumed tiny fraction of power compared to high voltage tubes and even the red leds, and it made possible to build the really complex (for that time) display of the 41CV / CX. So it is not the mark of cheapness, it was indeed a big deal back then both in technology and functional aspects. Your spotless package is an awesome find.

I have an HP 41C and 2 41CX's. An HP 97 and 67, I have had HPs since late 70s and I'm still using them. Very good investment.

Welcome to the HP-41 user club. Bring lots of time and excitement. The User keyboard was created as a way to deal with the problem of fitting all the functions onto the keyboard without having to have ever more shift keys or menus, especially with plug-in modules that added new functions. Being able to assign user programs to keys came as a bonus. It permitted the designers to _simplify_ the keyboard while introducing open-ended functionality. Compare the 41 keyboard with those of its immediate predecessor the HP-67, or the later HP-34C, both of which are the ultimate in uber-complex calculator keyboards. The 41 looked simple and streamlined by comparison, which belied what it was really capable of.

I have 2 HP-41 calculators. I was a flight engineer on C-141 aircraft and was issued a HP-41C to do my computations for flight and did a lot of programming to make it more useful. I also purchased a HP-41CX for my own use (I was into mini-computer and microprocessor design at the time). I got so used to RPN that I only use the HP-12C for finances and math. I use an algebraic calculator from time to time, but still prefer RPN.

I graduated from high school in 1971. Then in college, I saw the HP-35, HP's first pocket calculator, when it was introduced in 1972. I fell in love and was saving up money to buy one. I didn't get enough money until 1973, when the HP-45 was introduced. It had 10 memories and some extra functions. Using RPN was definitely a conversation topic. I remember many times, handing my calculator to a classmate who'd asked to borrow it for a calculation. They''d press a few keys then ask "Where is the = key?". There were lots of claims of "mine is better than yours" between HP owners and TI owners. I used to have a t-shirt with graphics on the front "ENTER > =". I got lots of questions whenever I wore it.

That beauty came out in the late 1970s. I was an undergraduate student of civil engineering and couldn’t afford one of them, but a friend of mine had one and would let me use it from time to time for advanced applications. My own calculator was a non-programmable TI 35(?) SR. When I started grad school I was able to get me a TI 49 that served me well for my MS degree. At the Iowa Institute of Hydraulic Research, where I went to study, they use to sell a thick volume of calculator programs for hydraulics and hydrology for both TI and HP programmable calculators. Those where the days of handheld programables. I didn’t owned an HP calculator until the early 1990s, when, as a faculty member at Utah State University, HP Boise send all of us free HP 48 G calculators. I later got me an HP 48 GX, which I used extensively in the courses I taught and even published books on calculator programs for probability and statistics, dynamics, and fluid mechanics. The HP 48 G series had a fabulous collection of reference handbooks that were very helpful in learning that calculator and it’s programming language. When the HP 49 G came out in the early 2000’s, the documentation was lousy. We had to use the documentation of the HP 48 G series as reference, except that the HP 49 G included a CAS (Computer Algebraic System) that allowed symbolic calculations to that calculator, something that the HP 48 G series didn’t have (it was a purely numerical calculator). I started typing a series of notes on the use of the HP 49 G CAS that became a book I used to sell online. HP Boise got hold of my book and in 2003 asked me to write a decent manual and user’s guide for the newer version of the HP 49 G, the HP 50 G. That was a great, hybrid (numeric symbolic) calculator, but it became obsolete by the 2010s. The TI 89 Titanium, and now the TI NSpire became the top-of-the-line engineering handheld calculators. HP tried a new calculator, the HP Prime, which hasn’t been too popular.

Back in the dark ages (early 1980s) I used an HP-11C for celestial navigation. I was very envious of the one student (we were studying to be deck officers on US merchant ships) who had a HP-41C. There was a navigation module that made entering things like what body he was using (sun, moon, planets, or stars) the time, and the uncorrected altitude of the body. A few more steps corrected this and gave him a useable line of position that could be plotted on a chart. Three of those and he had a good fix on the ship's position. All of this in less time than it took to explain it here. Only problem was the HP-41s were not allowed in our Coast Guard exams, but the HP-11C was.

I had one of these, and I wrote a program to help reduce my sextant sites whilst sailing the Atlantic in my 30 foot cat in 1981. Fabulous bit of tech. I loved it. It eventually succumbed to saltwater. Very sad. HP gear was beautiful in those days.

I bought an HP41C new when I was in high school, and kept it through college. I had the card reader, several modules, and the desktop printer, which also served as a battery eliminator. I ended up using it at work after college to automate some calculations for quality control of parts we were producing. I got rid of it after many years, but I now keep the i41cx+ app on my iPhone for when I'm feeling nostalgic. I still have several other vintage HP calculators in my desk somewhere.

What a generous contribution! Where I live a CX in such a good condition & complete in box would fetch around $500 on Ebay.

Yep I learned how to program on my HP-41C in 1981 when no one knew what a computer was. And I still have it and yes it still works. 😉

At the time, HP led the industry with engineering calculators. I was an engineering graduate student in the late 70’s and at that time the HP67/97 was the gold standard in programmable calculators (more correctly: scientific computers). Great video.

Card Reader was to read your collection of HP67 Calculator pre programed cards, (or collection of blank cards you recorded instructions on). It filled one slot and covered the other three being as tall as that piece of foam in the bottom of the calculator pouch. I still have my 41C I bought new back in the day. Along with my Math Pack 1, Stat Pack, Stress Analysis, Thermo Dynamics, Aviation X Pack and my Time Module. I upgraded from my HP67 which had the Standard Pack, Civil Engineering Pack, Business Decision Pack, Stat Pack I, Mechanical Engineering Pack, Math Pack I, and my Electrical Engineering Pack card library; but didn't ever buy a HP41C card reader, since I could load those programs into memory as needed. Big Dave

I had a 41C back in 1979 - a real game changer

I picked up a 41C (with extra memory) at goodwill a number of years ago now, so it is interesting to see the differences the CX has in operation that the original does not. Its interesting that the CX has a redish orange border for they keys whereas the C has a whitish silver one. Unfortunately I didn't get the documentation with it, but it wasn't expensive for what it is.

I had an HP11C in the 1980's. I programmed it to do synthetic division and asked my College Algebra instructor if I could use it for the final exam. He asked my if I wrote the program and to show him the source code and explain it. Once he was convinced that I wrote the code he let me use it. I finished the final in about 20 minutes.

The HP-41C is how I got through freshman chemistry class. I had the addon mag strip reader for it. Stored all the periodic table and important info on it and made good use of it for many years.

My first HP calculator was a HP-41C, the current model at the time, that my mom gave me when I was freshman in engineering school. I loved that thing and learned every little trick I could. I eventually got into what they called "synthetic programming" which was really just a hack of the interpreter to allow it to access protected areas within the CPU. There was a little program you could make called a "byte grabber". Pretty cool, you would press a hot key to insert a string that said it was 7 bytes long but was really only six. The interpreter wasn't happy so it grabbed a byte from the next instruction turning the now 6 bytes into a 7 byte instruction that did something new and undocumented. This chain would continue on through program memory until the interpreter was happy again. These instructions could not only wipe out your memory but completely lock the calculator up to where you had to leave the batteries out overnight. I had to leave the batteries out of mine plenty of times. I had many happy hours playing with that thing and it propelled me through engineering school. I had a magnetic card reader, a thermal printer, all of the slots were full. I had the circuit analysis pack, the math pack, the electrical engineering pack and a memory pack that took it up to the CV memory. I had some others I forgot the names of. I never felt that I could afford to buy the tape drive. Mine is in good condition but not as good as that one. I used the hell out of mine. I still have it and will never get rid of it.

(I was waiting to seethe price (@9:08) $250 pretty hefty price REDUCTION. An electronics engineer that my division worked with bought a much less complex HP calculator early in '73 that cost if I remember right over $1000. I do still remember how excited he was when it came and how he invited several of us (who sent problems to him and got solutions back) to his office to show us his "new toy"

I graduated from Oregon Tech in 1986 and got through it with an HP-15C? A wonderful calculator! The Model 41CX was the best at the time and 3x the price--amazing technology! And such great manuals at the time! Theirs, Commodore... The Radio Shack TRS-80 Intro-Manual and Advanced Programming Guide...you could figure out everything! And some video-game programmers did! And now off on a binge of RU-vid and their HP-calculator designer's videos :-)

I used to own the assumedly older HP-41CV years ago, with a magnetic card reader, thermal printer, UPC wand and about 8 modules. I sold it all on eBay about 10 years ago. One of my best memories was the ability to do "synthetic programing", which (once enabled) allowed access to prohibited areas of memory, and even allowed the defeating of copy protection on the magnetic cards. I'm new to your channel, and just saw this video, so I thought I'd mention synthetic programming and see whether you're familiar with it.

The 41cx included the time module and 2 memory modules. The foam block in the case can be removed to make room for the card reader. The time module includes a function to fine tune the time base . In the days before cheap gps, these were popular for sailboat navigation

11:16 Awww, my PKCell!!! 13:00 Stand by, I'm arming the nugget! I'll see myself out.

Used this model during 2nd half of college coursework in math, engineering & computer science. Also used a 16C. Excellent tools.

Back in the mid 1980's I was lucky enough to be able to buy a HP-41CX, I loved it! I went back to college in the mid 1990's to finish my degree. I decided to call HP to find out what would be a good choice since 10 years had passes. They suggested a HP-48GX. They also asked me about the calculator buy back program....I'm like tell me more....In the 1980's I paid about $300 for to HP-41CX, in the 1990's they gave me almost 1/2 off for a 48GX. The 41CX depricated only 50% in 10 years! Say that about anything else!

I got an HP41C while serving in the Navy. Nice to have such a complete system available and still be able to keep it in the limited storage space one has as a sailor. That place in the box you supposed was for a module is where HP would ship your first set of Ncell batteries.

A few years before this model when I was in the USAF, I was issued an HP35 while serving on an evaluation team out of Griffiss AFB Rome, NY. I fell in love with RPN. Not owning buckets of cash, a few years later after leaving the USAF, I had to settle for a Texas Instruments SR-56 (i couldn't afford the better SR-52 with programming cards) that (barely) fit into my budget but got me through the FAA's Radar A and B schools (but I still missed RPN).

The -41C and -41CX were the "must have" calculators for engineering students in the early 1980's. Unfortunately, they were crazy expensive. I managed to complete my engineering degree with a low-cost Sharp calculator. Brings back good memories.

I remember using an HP with an external thermal printer when I was in the Coast Guard in the 80s. It had a built in magnetic strip reader for the strips that had the programs stored on them. We used it for waveform analysis of the LORAN data. That was the first time I saw a calculator that used RPN. I think it was the HP-65.

I had a HP-21 in 1975 at college when everyone else had a TI of some sort. Using RPN for chain calculations in organic chemistry and physics was such a breeze. It died many years later due to battery corrosion but to this day I use a HP-21 app on iPad and iPhone. In 1985 I bought a HP-41CX and a Navigation module so I could do celestial navigation sun and star shots while sailing to and from Bermuda and elsewhere. I remember lusting after the HP-IL system and accessories like the printer and barcode reader but never got them. I put it in a drawer in the early 90’s and forgot about it. But a couple years ago I found it in the original box with all the original docs. I had removed the batteries when I stored it so it worked like new when I put in new ones. Been checking out 41CX videos to get reacquainted. What a great and fascinating piece of gear this thing is.

My dad had one of these for statistics and I played with it a lot when I was little. I got used to RPN and could never go back, and in college I bought a 48GX, which I still have.

FYI - If I am remembering correctly, the HP41CX also has the entire "Extended Functions" module built into it too, just like the time module you referenced.

There is a hack procedure called synthetic programming that you can do to this calculator that adds additional functions. Who knew that back in 1981 I was Jailbreaking my first device.

When I worked for Fugro back in the 1990s, we had two of those (boxed and mint and with mag-strip readers), which had been supplied as a way of manually calculating navigation fix positions in the event of the main PDP-11 computer failing. After the PDP-11s were upgraded to Windows PCs (in 1997), I enquired about what the plans for the HP-41s were - only to be informed that both had been dropped in a Norwegian dumpster a couple of weeks previously. Absolutely gutted didn't even touch first base on how I felt.

What an awesome device. That's super cool that you can create your own keyboard layout. I recently got a DM42, which is a terrific calculator. As others have mentioned RPN is so intuitive for solving multi step calculations. The swap and roll keys allow you to rearrange your data as you please with much more flexibility than on algebraic.

I worked at HP in the 80s, and I got to use a lot of neat calculators. We used the 71b, and the 41c for doing fun programmable and testing stuff, and the 28 was being developed but it looked pretty awesome. Ive never owned any, but Ive destroyed thousands of imperfect calculators, because quality matters

I had an HP 41CX that I got in 1986 and loved it. It lasted until the late 2000s when it got where it wouldn't turn on reliably and finally wouldn't work at all. I still have the HP 15c that I got in summer 1985 and still use it a lot and preferred it to the 41CX for some things due to having more mathematical functions on the keyboard for easy access. Also the HP 15c display was far easier to read. The alphanumeric display on the 41CX was neat and funky in its way of allowing all the capital letters but the numbers were harder to read.

Yes, bought a HP41C when I was an engineering student in 1982, was about one months rent for it but was worth it at the time. Still have it and still use it, the batteries are 20 years old and still work! Love the RPN calculators, once you get used to is you never can go back.

I had one of these (without the X) and taught myself programming with it. Times were tough. Loved it! I don't have it anymore. I'm jealous.

I have one of these (41 CX) myself, all I need is the HP-IL to HP-IB converter so I can have some fun controlling some of my HP instruments, and send plot jobs to my HP plotters.

Wow, it's amazing when you find something that's really old but still in really good shape without needing much or any restoration, isn't it?

Never used the 41. I used the 48 series in the USAF. Have a 48G, 48SX, and 48GX in my collection; along with quite a few manuals and books. They're great mini-computers!

That is honestly the earliest example of operator overloading I've seen so far. What a beast of a computer that must have been back in the days

I had a pocket computer in college back in 1982. A Radio Shack PC-2. It still works today. And the printer cassette adapter.

I had an HP 41 CX back in the day. Prior to that I had a TI 58 then TI 59 and the 41 CX was a big step up. I did have a couple modules for it, including the HP IL which I used for interfacing with HP test equipment. At one of the jobs I was issued an HP 71B as well which was also used to interface to and control test equipment. Eventually I moved up to the HP 48 SX then the 48 GX, which I still have and use regularly. In fact I have iHP48 app for my iPhone and still run a bunch of the programs I've written over the years on the iPhone because I have that with me most of the time and it is a zillion times faster than the native HP 48 GX.

One of the many HP calculators I've owned at one time was the HP-41c. The ASN function was often used in programs to assign specific functions to keys. Those programs would come with those clip-on overlays with the assignments listed on them.

You should get the successor of this calculator: HP 42S! It's a classic always in high demand

I still have my 41-CX. It works fine. There was something about the feel of those tactile switches on those early HP calculators that just oozed quality. The programming you can do can be very sophisticated. What it won't be is fast by today's standards. I guarantee that solving a 4x4 matrix was far faster using the calculator than working it out by hand.

I added HP-IL (hewlett packard instrument link) to my HP41 to control laboratory instruments (gas chromatograph, autosampler.) Circa 1985.

I used HP calculators in high school and when studying in the 90s, but later it became a bit of a collection of mine. I think you'd also love the HP 67 (or 65) if you can get your hands on one in good condition, and some magnet cards.

My HP41 is still working got it as a student and I’m 60 now. Still use it. ❤

The HP 41C was my first computer. I was working in an electronics company and I used it to calculate MTBF for power supplies. The engineer who sat next to me bought himself a Heathkit H8 computer and spent weeks getting it to do anything at all. The HP41 had all sorts of engineering modules available. The most useful accessory for me was the magnetic card reader/writer. I could store custom programs on separate cards and make custom keyboard overlays. I wish I still had it! I bought my first PC in 1984, a Columbia MPC-1600 IBM clone. I never bought one of those 8-bit computers such as the Apple II or the various Commodores or Atari's. The seemed like glorified game machines to me. @CharlesWT-TX reminded me of a big personal advantage of having an RPN calculator, whenever anyone would ask to borrow it I'd tell them it used RPN. The borrower would look at me blankly and they would return it to me after a minute or so and say "It doesn't work!" 😛

I still have mine and a card reader that plugs in the top. I used it a lot when I was taking electronics classes in college. I remember programming it to play a hangman game where it actually showed the gallows on the display. Haven't looked at it in decades but if I remember correctly, the battery corroded inside it and ruined the contacts.

5:01 just that little caress of the page.... that says it all, it even sounds like a nostalgic nerd sigh, I'm right there with you! :) I used to have that same feeling looking over shiny camera catalogues, things i could not afford but seemed to be the solutions to problems i wanted to have.... aaahh the nostalgia! I do love the HP-11C, love the form factor, not willing to pay the price for one these days though!

I loved my HP41C series. I had 2 calculators, many modules, mag card reader, printer, wand and more. The calculators I think have bad on/off switches, otherwise good. I now use the iOS version of i41CX+. Fully compatible with all HP41 programs, if you want to type them in or can get them into it as a text file.

Never liked RPN. Loved the shape and feel of the HP-11s and frankly I understood it since I could use a slide rule, it just didn't take advantage of the technology.

Best calculator for ever, my first is from 1982 and is still working

Would you consider doing a video on a TI-57 II. It's an odd find because my late father was an engineer and must have got it during his apprenticeship. Found it some 15 years ago in some old tools and didn't think much of it then, til recently when I was in the garage at the mothers looking for an allen key and realised what it was. It's kind of interesting to me, especially as a software dev who mostly works on legacy transactional systems and automation. I don't know how interesting it is to guys who really like their calculators. If you'd like to borrow it for a video, I'd be happy to ship it over.

I was a gear engineer for an auto company in Detroit from 1977 to 2007. In the early 80's I started with the an hp41c. Then I bought a 41cv and two 41cx's. We would start the preliminary design using slide rules and the programmable hp's. Then we would go to huge Fortran programs on the mainframe computers. They would print out on green and white striped paper that we would cut to 8.5 x 11 inches to fit in our file folders. There are still many millions of vehicles driving around with transmissions and axles that I designed in this manner with the hp calculators. Some are still being manufactured. I also had the card reader and thermal printer. I kept two calculators at work, one at home to use, and another at home as a backup storage for the programs. I never had a RPN (reverse polish notation) hp stolen out of my desk. I suspect they couldn't figure out how to use it and just put it back. Later I had 4 hp48's, one hp49, and one hp50, and then the hp prime. My all time favorite was the hp41. Since being retired, I have sold all my hp calculators except for one of the 48's. We use to buy hp calculators from a place in Oregon called Educalc. They had a great catalog and fast service. We also had one hp calculator with a built in printer. I think it was an hp 97. I also had an hp42. I spent many 10 to 12 hour days crunching away on those hps. The early ones had the numbers and digits cast all the way through the keys so they would not wear off. Hp was the calculator king back then. This was a fun trip for me to go down memory lane, back when engineers were true geeks (With our slide rules on our belts) and proud of it. We would tell other people "Don't make fun of the geeks, one day you will be working for one".

We all had the CV in engineering school. If you were a real engineering student you had one of these. I think they were $300 in 85. Quite a hit for a poor student. But worth every penny. Got me through fluids, thermo, diff eq..you name it. I just got an HP Prime. What an upgrade! Wish we had these back then! Still love the ole’ 41-CV. Could not have done without it

I bought my HP41C in 1980. I still use it as my everyday calculator. I even have a HP41C app on my phone to use when it is not to hand. Can't stand regular calculators

I have more of these than sane people probably should. I don't have any CXs though; all mine are C or CV. I use them all the time, with peripherals. After this, HP just never quite got it right. The 32SII was the only thing almost as good. If only they'd made a 32S like calculator with 41C hardware, or at least a 41CX with inbuilt fractions and solver, and nobody would ever need a different calculator. Incidentally these weren't just used on-the-go. Many companies used these as special purpose computers in industrial (and other) applications. I don't have the GPIB interface (and don't want one because I don't need to get that deep into these). But if I did, I'd be very tempted to connect an HP41C to my Commodore 9060D hard drive.

I earned a B.S., M. Eng, PhD and PE License in electrical and computer engineering with a Casio FX115ES Plus. While my classmates were being total geeks trying to figure out how to program their HP48GXs, I was learning the course material and smoked them all on exams.

I bought mine (maybe only a -C) in the early 80's still have it, don't remember if it still works. Batteries are type "N" Being a mainframe computer programmer, I actually used the HP-16C more (for it's hexadecimal capability. I tried tot turn the 41 into an hexadecimal calculator but it was just too messy) I still use the 16C to this day for it's RPN and quality, although I am retired and don't need the hexadecimal capability anymore As I remember I spent over $400 in 198x dollars for the 41 and other stuff, (expansion module(s) )) A note about the batteries, because of the LCD display instead of LED, the batteries lasted for what seemed forever. My only real complaint about the 41 (and the 16) was that the stack wasn't big enough

The thing I miss most going from hp41c* to hp42s is the ability to completely reassign the whole keyboard rather than just the top row. That's a bit of an ergonomic downgrade.

i migrated from my 1st calculator in 1989 (hp42s) directly to hp prime this year (it's like water to wine -- and i used to program my hp42s in assembly with plenty of custom functions 🙂 )

The reason they called it a calculator was when you ordered it thru work, the purchasing department would see it as a calculator not a computer and ok the purchase.

I had a 41C and then a 41CX and did my first programming on them in the 80’s. 40 years later I am an AI developer, but still use the 41CX- however, it’s an app on my iPhone and comes with every single module for free.

"5 whatevers" This is my new favourite unit of data quantity!

Hey, I used to live in Vancouver! Thanks Alan!

15:09 The advantage of RPN is you don’t need rules for operator precedence or parentheses to get around them. The disadvantage is that normal people seem to have great trouble understanding it. For example, I did a lot of programming in PostScript, which was very popular in high-end laser printers and typesetters back in the day. I tried explaining how it worked to colleagues, but they never seemed able to grasp the concept.

it's a miracle the reflective screen layer has not oxidized and darkened/ruined

I am just watching you HP-41CX video and it reminded me that I have an HP97 which has been just sitting and it could use a good home. It is not it good condition because it has had a very well used life, but it should be working. It is a fully programmable calculator with a magnetic card reader as well as a printer. I used this machine all day every day back in the 80's. The HP97 has a magnetic card reader and I have a lot of HP cards as well as a lot of custom programs that we wrote and used everyday. This was the computer I used everyday. I think I have a the manual as well as a box of thermal paper for the builtin printer. if you are interested then I would be happy to send it to you. I don't really know how we communicate so I will watch to see if you comment and I guess we can go from there. I very much enjoy your contact.

I got a 41CV in a rather unconventional manner. My car was stolen, then 6 months later it was recovered, and filled to the brim with random junk. Deep in the pile was the 41CV, leather case, and manual. Had to clean up the messed up battery terminals but it works great now.

Back in the day I bought a 41CV while I was in the Navy, got the statistics modules when I started university, failed miserably in statistics, lost the 41CV, got a 41CX, spent the summer 1988 learning statistics and writing my own programs which I stored on the magnetic strips and then passed statistics without even touching the calculator 😊 One of my programs got published in a german computer magazine. Later I sold the 41CX to help me pay for a HP-95 which then had to go for a Psion 5, I should have kept all of them!

My brother's calc for college was a 48Sx, another crazy expandable powerful calc

I use a HP48GX that I got from my dad, still works great!