HP 35s Scientific Calculator

Full Description

5 Reviews

1. The thing comes with a “quick start guide” that says press ‘c’ to turn it on. That did not work as had no display. Tried the HP web site and could have saved some time. Then found how to call and that also was a waste of time. Don’t bother entering the model number or the serial number for a calculator on the web site as that just gets you to the error page.

   Then noticed that there were to batteries in the package taped to to the CD. So used the manual to go to page 43 which the index said was “how to replace batteries”. There is nothing about batteries on page 43 or the previous or the next. I then assumed that “made in China” also implied documented in China and some translations got missed.

   Having had an HP calculator since my 35 I think they no longer care a S^%$ about them as no money any more (the 35 and the 45 cost !!!!!!!!!!! compared to this one.).

   So yet to use it but given what has happened so far learning how to do things with this one using a manual with known errors sure looks like a major pain. Guess must learn Chinese to do better.

   Rejoice … the manual is in English … well sort of anyway.

   Solution: Guess as to how to get the thing to work out of the box.

2. bought one of these to replace my trusty HP11C. whereas the HP11C has a very clear liquir chrystal display the HP35s has a pixal formation of the numbers which just is not as clear to read. HP still make the 12C so why not the 11C or 15C that so many people love. its smaller and much nicewr (solid) feel then the plastic China made HP35s. anyway I want a RPN so there are not too mmany choices. fortunatly the 11C did not die so the 20 year old unit is still the first thing I grab.

3. Being a long term HP user I can say without a doubt that the solid and quality feel that old HP calculators use to provide is gone. This calculator looks a little big but weights little, it feels “empty”. The plastic parts are not as good as the old ones. The keyboard feels almost like the old ones, I haven’t missed strokes as other users say. The ON key doesn’t work as it is supposed to (following the shift color logic): Do you need to press the blue shift ket in conjunction with the C key to get it ON?? NO. To turn it OFF any of the colored shift keys do the same thing. Besides, the arrows showed in the shift keys don’t have the correct logic, according to the way the functions are printed, the blue key seems to be upside down. I like the display arrangement, but the old 41 series display was way better and unique. Haven’t used it for long or for complex calculations but it works ok. Finally, one of the additional things that HP users liked was the professional spiral bound manuals, now you need a computer with a cd player (a netbook is not good enough) to read the manual of a calculator!! Absurd. Today’s HP calculators are not above the competition the way they use to be. 20 years ago you could be proud of being the owner of a HP calculator, today is not easy to justify purchasing one. Anyway, for me, there is still NO WAY to use a Casio for the simplest calculation, it has to be an HP because of the fabulous RPN, so having this one is a bitter sweet feeling.

4. A very good Calculator for the price. I have a HP 48S that I used for years. I bought the HP 35 for my PE Review. This is one of two HPs permitted in the exam room.

5. The hp 35s is very worthy update as the at-your-side workhorse math and engineering calculator. Like many old engineers, I’m a little crazy about how good a calculator can be, so this review is a bit long. If you miss your old hp15c and want something to work in RPN mode, this is a good modern rendition. Algebraic mode is ok, but a little less well worked out. While mostly good, there are a couple real flaws in the calculator, described below.

   Good news: the physical aspects are well done: the buttons are good, the display is clear, it’s light and fits well in the hand, and it comes with a good slipcase, and the manual seems pretty good. The 2-line display is great compared to the old 1-line models, often allowing you to see what you keyed in and the answer simultaneously. The feature set is close to the sweet spot for math and engineering. The 35s has the common math functions available with a logical button layout, and it mostly has good support for complex numbers. Simple programming is available — many will never use it, but it’s neat to have it in reserve if you get in a case where it’s really needed.

   Bad news: while most of the interface is fine, there are a few bizarre flaws.

   The most boneheaded design decision relates to how “all” mode, the default display mode, works. Suppose the result is “1.1234567812e-12″ Depending on how many digits there are in the fraction, what appears in the display is “1.123456781e-1″ — instead of showing the full “e-12″ exponent, it just shows what fits, like “e-1″, and there’s a little extra annunciator in the display, telling you that you need to scroll to see the rest of the result. It’s unfortunate that the displayed result looks very much like a final answer, and you need to notice the annunciator and then do these extra key strokes to see the number. Obviously seeing a numeric result is kind of a common case for a calculator! You can see in other reviews how some people are confused by this “why can’t I just see the answer” case, and can’t understand why the calculator makes it so hard. The correct design for progressive disclosure of information is to show the *most important* information first, and allow the user to see the details if they care. In this case the “e-12″ is very important, where the 8th etc. digits of the fraction are the least important. The way it should work is display “1.1234567…e-12″ — showing the information you most care about, and the “…” is the cue that more details are available, and a keystroke in that case can scroll to show the whole result. The reality is that 99% of the time, the user will be happy with what’s displayed, and no extra keystrokes are required. That’s how it should work. The workaround is to run in “fix-6″ mode or whatever, preemptively limiting the digit range available but avoiding the unusable “all” mode.

   There are also flaws in the trigonometric functions where they drop significant precision for cases near 90 degrees, vs. the 10-12 digits expected. For example tan(89.99999) returns 5,729,578.122 which is incorrect beginning at the 8 (google for hpmuseum hp35s bug list). Though unlikely to cause practical problems, this sloppy attitude about precision is not what you want to hear about your calculator. I can’t imagine how they could have thought that being sloppy with arithmetic was a ok idea .. they’re in the *calculator* business for gosh sakes. I’m so sorry if they find it a bit trying to get all those fiddly little digits correct! This is also sad given the amazing reputation for precision of the earlier generations of HP calculators. Or perhaps it’s just irony — William Kahn, a giant in the field of computer science for designing accurate computer arithmetic, was hired by HP to fix problems with transcendental functions in the original HP 35, and he went on to create the extremely accurate arithmetic for which later HP equipment became famous (see Kahn’s wikipedia page). Since the HP 35s commemorates the original HP 35 … perhaps they put some bugs back in to really capture the spirit of the original! (Of course HP fixed the original HP 35.) The 35s bug has been public since 2007, and not a peep out of HP. I can’t imagine how HP got in a situation where fixing their own product is too hard, so they just keep selling it with known flaws. (Organizational tip: don’t fire *everyone* on the engineering team … always keep that one guy just in case!) Nobody should have to think about if they happen to be hitting a case where their calculator is inaccurate. HP pioneered that idea.

   The complex number support, a real core use case for engineers, works pretty well on 90% of the functions. But on 10% it just fails and returns “syntax error”. It kind of takes the fun out of complex number support if you are trying to remember which nicely labeled buttons do and do not work.

   Small feature wishes: I wish STO/RCL were separate buttons, and it’s ok to maybe make MODE and some of the programming buttons a little more buried. I suspect that’s a better fit for the common use pattern. Ultimately, the design team should have a 100 hours of video tape to support what the real use pattern is, or just hand out instrumented calculators to college students. When I enter a number and hit 1/x or SIN in alg mode, it should just do the right thing .. don’t be hidebound to the input paradigm, instead hack the input processing to make the common cases work. In fact I would make a little animation in the display for that case, as it fixes up your input. That would immediately be the most memorable and talked about feature. Also the polar/rect and complex disassembly features are missing, and those are pretty common engineering cases, and the trivial unit conversions maybe don’t need so many dedicated buttons. Don’t add buttons; the size is already good. Just use the existing ones better + use menus for the rare cases. I understand the curb appeal of unit conversions, but let’s get those buttons back for real engineering cases. Finally for hex conversion .. I wish it just knew when I was entering a hex number and let the a-f letters just work. I have a $12 calculator that gets that right. USB or sd card support would be nice, but not vital given that the programs aren’t that big. I don’t think huge programs are that important vs. the core engineering cases, although obviously there’s a vocal group that loves extensive programs. I am the right amount of crazy; those guys are too crazy!

   So in summary: I actually like this calculator. It’s almost very good, but it’s just got a couple baffling flaws. They did a nice job with the physical form and the feature set is near the sweet spot. The flaws just seem like bad decisions or they were in a rush or something — not like it would have been a big added expense to get them right.

   Now here’s some free advice for HP management to make an additional billion dollars each year. I await my pallet of thank you gifts.

   A high school or college student or engineer can bond with their calculator as the instrument at their side that they are using all the time through those hours of problems. That’s why you see so many crazy people like me on the internet commenting on calculator details where any normal person figures .. who cares? Nobody bonds with an HP laptop vs. a dell or whatever. You can’t really tell them apart in reality. But the calculator has a *physicality* … you live with the buttons and the display and the interface so much going through that crucible, if the thing is built with conspicuous high quality and great design, it makes a real impression.

   So here’s the strategy: take $20m a year out of the HP marketing budget, and just spend it every year beefing up the products of the calculator division, and selling them at a premium, but still below cost considering the fantastic quality. It will be a covert form of marketing. Make physical forms that grow famous for indestructibility and 8 year battery life with intermittent use (that would be a neat sticker on the blister pack!). Think Maglite. The display and buttons should just be excellent in a way where a TI or sharp is obviously kind of lame next to the HP. The feature set does not need to be huge or the programmed loops fast, but (as above) the interface should be exhaustively researched and tuned, so the keystroke sequences just feel spot on. As a bonus, once you have the interface design well worked out, you don’t need to change it a ton. The high end will be owned by computers and phones, so stick to the core math/engineering feature set and make it perfect (i.e. the hp50g market is not the future). Figure out an optimal form factor and button plan and stop messing with it. Don’t shortchange the software to save 1000 bits on some chip .. the high quality software and design and its reputation is your expensive long term investment, and the chips will take care of themselves. Steve Jobs understands this.

   Now in 5 years time, what you’ve done is produce this army of former students who have a strong feeling in their bones that HP produces high quality, well designed, jealousy inducing instruments. Imagine that as a holiday giveaway, every HP employee gets a calculator to keep or give to a neighbor or whatever, and they are honestly a little *psyched* about the gift as it is conspicuously and famously top of its class. It’s hard to name an HP product like that today, because they’re all on the economic margin. This trick works for HP, and not for Sharp et al, because HP has this ocean of high end gear to sell, and the little piddly expense of making over-the-top high-quality calculators is nothing compared to enabling a few more high-end sales. As a bonus, it provides the whole company something to be proud of. Windows laptops and printers are not lovable, or even likeable in the same way, but as mentioned above, I’m crazy!