I like the DM15L as much as my HP11C. Faster and 40 years newer.Swiss Micros is about the only game in town for new RPN calculators. I collect them, I use them. I use the DM15L in my living room with the big TV while surfing the web. Handy for those quick calculations that don't require any programming. I always liked the Voyager (Landscape design). Screen is very readable. Buttons are fine. I also bought the DM15 credit card sized version which is a great novelty, but the buttons are too stiff to use as a daily driver.Cheerleading for Swiss Micros below:My HP41CV has broken posts, bad z-strips, and battery terminals. With manipulation, I can sometimes even get it to power on. My HP41CX is still in great condition except for the battery terminals. It faithfully powers on, but I know it will probably quit before I do. I got the DM41X masterpiece to replace those two. The DM41X improves on the HP41CX with many conveniences like the custom menu and USB interface that simply make the DM41X my daily driver on my desk. The custom menu supplants the plastic overlays from the 41's that let us repurpose seldom-used keys.The DM41X claims to support overlays, but didn't come with any, and my attempts to use a Cricut to create overlays for the DM41X have been promising, but ultimately disappointing largely due to the thin, flimsy overlay requirements. The old 41 overlays were at least three times thicker than what can be used on the DM41X/DM42.I have the HP 49 and the HP Prime (which will likely be my last HP), but my glory days were with the 11 and the 41 series. Swiss Micros understands that bond and has excelled in feeding my passion for these classic calculators.
Ok so some of you probably know a weirdo like me who collects calculators. I know I'm not normal, I long y calculators. I don't even really use them for work but I never got over how useful they were.Anyway growing up I used my Dad's HP 11C which my brother ultimately lost. So about a decade ago I went and bought my own used HP 15 C and one for Dad as it was superior to the 11C. I loved it. But the calculator was showing it's age.I used my Dad's 11 C in calculus in highschool and ultimately upgraded to a Ti 89, and an HP 48 G series.One thing I loved about the HPs was RPN. Anyway I deployed to Iraq and while overseas I missed the opportunity to buy the HP 15 C limited edition. These days you can buy them but because of how few are out there you need to purchase a second hand item at prices upward of $1000.When I discovered the Swiss Micro DM 15L I couldn't pass it up. It arrived in a timely manner, especially considering it shipped from Europe. But more importantly this machine rocks.I don't have a 15C limited to test it against, but it certainly is faster than my older model. This calculator uses the exact same voyager layout as the 15C, the feet are sturdier, has a USB port, uses RPN, and is without a doubt my new favorite calculator.If you know someone who collects calculators this is definitely one to give them. I absolutely love everything about it. The keys, the machine work that went into the casing. This calculator is great.
I purchased the Swissmicro DM15L, and the calculator was great at first, a good equivalent to the HP 15C. I have an HP that is over 20 years old and works with no problems. The DM15L display is going out; there are several dead pixels spot; at first, no big deal, now it is interfering with the actual number display. Since it is still under warranty, I reached out to Swissmicro support with no response; I emailed them again a month later and included several other Swissmicro employees, and still no response. Now the calculator is useless! I have given the rating purely based on customer service or their lack of customer support and would not recommend their product due to lack of customer support.
First, let me say that I am very grateful to Swiss Micros for making these available. I had an HP 11C for many years and have regretted parting with it the very minute I did so. Luckily I was able to get this DM15 as a replacement. Overall I am very pleased with it!Before going further, I should let you know that the display bezel on the unit I received did not fit properly and was peeling off when I received it. Because I am a manufacturing engineer, I spent some time assessing the problem. The company offered to send a replacement bezel but I thought the best solution from my perspective was to simply make the repair myself.The problem was that the display glass sits a little proud of the mating surfaces on which the bezel is intended to sit. To fix this, I took the following steps: 1. I removed the adhesive film from the back of the bezel. Then cleaned this surface and the mating plastic surface on the calculator body with lighter fluid. 2. Carefully adjusted the bezel to make sure it was perfectly flat. It previously had a slight curve upward. 3. Using 5min. epoxy, I carefully re-glued using a toothpick for an applicator. Had to hold it down very carefully for a few minutes but turned out just about perfect.So why, you may ask, did I still give this 5 stars? Because strange as this may sound, I feel that the value of what Swiss Micros is doing is so important that I also feel a sense of committment to "the cause". I really, really, really want them to be successful. Handling a small problem like this myself makes me feel like I am a part of the effort. Maybe I'm crazy or maybe I am a small part of their success. I certainly hope so!There are many other reviews of a technical nature, most of which I agree with. No need for me to repeat them.Overall, I love having something that is a reasonable approximation of my old HP, and maybe in some respects a bit better.
These days there is not much need for a calculator these days more powerful than this. For more sophisticated work I could fire up Mathematica or write in Fortran, or R. However, a scientific calculator from time to time is handy, and this one is a recreation of one of the very best, emulating the HP-15c using the original ROM code. There is no need to liberally use parentheses to get around wrong operator precedence (looking at you, Excel); because in RPN there are no parentheses.The firmware of the DM15L has a little more memory available for data and code than the HP-15c. Externally it is like the original except for a micro-USB port which could be used to update the firmware. It does not take power from that port. Battery access is different; and beware that a violent drop might knock the battery loose.Its keystrokes are little stiffer and a little shorter than on my HP48G, but distinctly positive, and much better than typical rubber dome keys of other brands. The keys are painted. Alas, the days of double-shot injection molded keys are long gone. It is too early for me to tell about battery life, although you can set the CPU speed at either 12 or 48 MHz which I imagine would not have the same battery lives. At 12 MHz it is still faster than the original. The backside, like original, has the “micro-manual”. The contrast of the printing could be improved.The nice thing about the clone is the HP-15c manuals apply, and are freely available. The Advanced Functions Handbook is an education in itself. Because it uses the original HP ROM code, the numerical methods used by the machine remain outstanding. There are no bugs that I can find; typing in examples from the manuals produces matching results in all cases I have tried.The handiest (for me) feature this calculator has is linear regression; so easy to use, so easy to undo mistakes, just right for making calibration curves for [in my case] chemical lab equipment. Need to solve a system of linear equations? No problem (if more than 3x3 typing is tedious enough to want to use something else). Numerical integration? Robust. Root solver? Robust. Complex numbers? Yes.In short, it does anything you’d need out of scientific calculator [not out of a computer] and does it well. It’s handy. If HP wanted to issue the HP-15c for the third time, they could do worse than to go to Swiss Micros to make a production run. 5 stars.