22 replies to this topic

[Hlib2]

An attractive appearance and a convenient, easy-to-read keyboard are important criteria for any calculator. I made an attempt to analyze the evolution of attitudes to this topic among various manufacturers.
1) These are classic representatives of calculators for high-paying consumers of the early 90`s: hp-48gx(~$1000)/ti-85(~$550). Approximate retail prices are given in the modern equivalent for 1993. For such a price, the manufacturer did not spare the paint for the letterings.


2) ti-85/fx-2.0. In 1999, CASIO released the fx-2.0 model(~$300 in modern equivalent). Note the size of the labels for x^2, 10^x and e^x on the left and right. This extravagance on the right did not extend further to arcsin, arccos etc. But in general, the inscriptions are quite satisfactory.


3) fx-2.0/graph25 from CASIO. The quality of the paint above the keys in graph25 is slightly better than in fx-2.0. However, to compensate for the cost, the letterings are either thinner or smaller. Visual perception has deteriorated.


4) graph25/fx-9850gb+. It seems that the price of paint exceeds the price of gold. According to some distributors, modern buyers can`t afford an extra $1 for the beauty in one calculator, so here we see another masterpiece of design thought.


5) ti-83+/ti-83+SE. Texas Instruments took care too of low-income engineers and students, saving on design. In the "Silver Edition"(sic!) the LCD was also "optimized" (by reducing its quality).


6) fx-991 classwiz(brand new)/(used). After several months of using the device in the production room and after a dozen wipes with a dry cloth from dirt, the inscriptions above the keys became unreadable. And then my talent as a graphic designer was awakened ...

[MJim]

Wear and tear of the printing on calculators is something that unfortunately isn't featured in reviews.

 

For myself the Casio fx-991MS 2nd edition has to me the nicest printing for labels I've seen so far in a calculator; but it barely gets any use (and has had it's battery removed and been packed away as of today) so I doubt it would fair much better than your fx-991ex.  What does impress me though is that the printing on the fx-991ex buttons presumably got similar treatment but seem unworn to me, so that is something in it's favour (I have some old fx-82AU Plus's and all of them have some sort of button print wear).

 

LCD displays also deserve to get a decent review as well.  Initially I thought the contrast was decent on the fx-991MS 2nd edition and it was great having the contrast adjustment, but the calculator as I discovered would be very difficult to use without it.  It has one of the worst viewing angles of any calculator I have used, forcing you to lower the contrast if you aren't looking directly at it; it may look dark and contrasty straight on, but once you are at any angle it gets progressively harder to read the digits until they all become "88888888's".  Older single line Casio's and Sharps don't suffer from this problem (I just acquired recently a Sharp El-506P from the mid eighties that has both a great contrast panel and fantastic viewing angles), although most of the modern natural VPAM models have great viewing angles as well....perhaps it is just the 2-line Casio's that have the viewing angle problems?

 

In any case good job putting the labels on...still, I have to ask why do you have such a huge label for the QR button

Edited by MJim, 07 September 2020 - 02:47 AM.

[Hlib2]

Hi, MJim! I agree that "wear and tear of the printing on calculators is something that
unfortunately isn`t featured in reviews", as you`ve mentioned. The size of the labels and the correct color scheme in the design also matter.

I have to ask why do you have such a huge label for the QR button

Oops, I was going to draw a NFC support :-)
The market for scientific calculators today is focused on a huge number of consumers who are poorly versed in the merits of the product.
Scary and incomprehensible letterings (LCM, GCD, log, HEX, List, nPr, Rec) should not be conspicuous, so as not to frighten potential buyers.
Advertising tricks from the last century (64KB RAM/3-colour display/basic-like programming/1.5MB flash memory) now may bring a smile to the smartphone`s user.
Abbreviations like QR, 5G, Gorilla Glass, USB power, SOLVE, COG LCD are modern, cool and attractive, so they should stand out from the general background.

Edited by Hlib2, 10 September 2020 - 05:45 PM.

[MJim]

I was poking fun at the QR verification feature having such a big spot, but I think that you can use the QR function for graphs, so that backfired a little.

 

I picked up a Casio fx-570s quite recently; the first generation VPAM model which doesn't feature a 2-line display, nor does it support implicit multiplication.  It does have an interesting styling choice where it paints an Aluminium front cover with black-paint.  Certain letters like the hexadecimal characters are displayed by removing the black-paint to let the silver aluminium shine through.

 

It has a terrible display though, and interestingly, the internal LCD display is set tilted slightly towards the operator, making it difficult to read while looking perfectly perpendicular to the display.  I don't know what happened with Casio's display quality, but it took me obtaining an old Sharp EL-506P to realize how fantastically vivid 7-segment LCD's actually were from the 1980's.

 

I put 3 old calculators together (all 3 have pretty much brand new batteries) to show how their displays look front on and from a angle.

 

Front:

Spoiler

 

The Contrast on the fx-570s is pretty bad compared to the other older calculators.  Part of it can be explained by the clear plastic window adding to the overall number of reflections, but it is still much harder to read regardless.

 

Side:

Spoiler

 

To be fair the plastic window doesn't help the fx-570s much with reflections, in fact this second picture I tried to use a polarizer to cut down on the reflections (which is hard to do without turning the displays black) to show how at steep angles the fx-570s display becomes unreadable since the other unused segments become dark.

 

I really love the little Sharp EL-506P, but I'm currently attempting an introductory course on probability online, and I am very much missing the nPr & nCr buttons.  I would love to get a hold of the EL-506A (it's successor).

Edited by MJim, 18 September 2020 - 04:44 AM.

[Hlib2]

I don`t know what happened with Casio`s display quality ...

Displays in handheld devices are a separate broad topic. I believe that the quality depends on the customer`s requirements, not on the manufacturer. Here is a typical example:

On the left - a LCD with good contrast and large viewing angles (1995).
On the right is a terrible display in CASIO products made for another region a year later (1996)
Next picture: the two same TI`s calcs. Left is made in 2004, the right one is from 2000.

Here the differences are not very noticeable, but there are cases much worse.

[MJim]

Thanks Hlib2 for providing some examples of display quality. 

 

When talking about Casio's display quality I was more referring to the segment display versions, but perhaps I'm being a bit unfair; as I do have an old fx-82LB which has pretty poor contrast compared to it's successor the fx-82SX.  However, while the fx-82SX has better contrast for the most part, it also suffers from problems with a narrow viewing angle (the same problem I see with the modern fx-991MS 2nd edition), while the fx-82LB maintains it readability through a much wider angle.

[Hlib2]

... perhaps I`m being a bit unfair; as I do have an old fx-82LB which has pretty poor contrast ...

fx-82lb was my first scientific calculator from CASIO, which I bought back in 1995 in its advanced reincarnation (on the right). I don`t have this calculator at the moment, so the image is borrowed from Google.

The new fx-82lb had the DEL key (➝) and the BASE-N mode.

[MJim]

fx-82lb was my first scientific calculator from CASIO, which I bought back in 1995 in its advanced reincarnation (on the right). I don`t have this calculator at the moment, so the image is borrowed from Google.

The new fx-82lb had the DEL key (➝) and the BASE-N mode.

Hey!, the one on the right which says it is a casio looks to be another Sharp EL-506P clone; compare it to the one I posted above, same keys and functions.  The one on the left is the one is the fx-82LB I have.

 

I decided to post both the fx-82SX and fx-82LB to show the contrast problems with the fx-82SX at wider angles (apologize for the drunken looking angled shot):

 

Front

Spoiler

 

Angled

Spoiler

As can be seen all the unused segments become visible at steep viewing angles for the fx-82SX and that also seems to be a big problem with the 2-line series from Casio.  In saying that, the fx-991W (probably my favorite of all the Casio's I've used so far outside the graphing ones) is subject to the same problems, though now the display cable is disconnected and in need of a new one, so it's more or less out of order for good.

[Hlib2]

A logical question arises: why couldn`t the manufactorers of El-506P clones add a few useful features to their product (nPr or nCr at least)? Answer: the original developer and the project`s sponsor is unknown to us. We only see the end result under different brands. Here is an example of three calculators. Guess three times - who is the two excess players in the market? Yes, those are customers for the CITIZEN and HP brands.

I have never seen a better keyboard and lettering in calculators than in the SRP-325. In addition, the weight of the srp-325 is 85g (against 125g for HP). But CITIZEN didn`t have enough money for a good display, they even made a decimal point half a pixel in size. As for HP - they saved as paint for inscriptions as for the normal design of the case.
CASIO probably still wins. Junk like the fx-82sx is bought by 90% of calculator consumers.
Following picture: dark gray pixels in some batches hp-50g instead of real black pixels as in hp-48gii and rejection of the Japanese style in the design in favor of a terrible black body. I don`t understand all the nuances of big business.

[MJim]

I would love to know the origin story about EL-506P clones, since even today you can still purchase them in one form or another; the give away being those "a" and "b" buttons, which are used for complex number (a + bi) calculations (although it is used for rectangular to polar conversions as well).

 

Looks like in the case of the SRP-325G some extra effort was put into rearranging the keyboard.  Don't think I like having the number keys sandwiched between other functions, as on the HP 9g, and the number placement is a lot more normal on the SRP-325G.  I think I can see that the SRP-325G has nice easy to read labels, but, and this is a purely subjective opinion, it is very ugly to me (alright, I admit I'm not a fan of blue as well, so that doesn't help), and I'm also not a fan of that navigation button, though it is just as bad on the HP 9g.  I also prefer the colours for the labels on the HP 9g, even though the size isn't quite as good (maybe orange and green paints cost more than white and blue?), and I also like that the HP 9g uses a dimmer blue color for their letters, as on the SRP-325G the number keys looks cluttered by having both white numbers and letters on them.

 

The HP-50G and HP-48GII comparison is interesting; I started up my old HP-49G+ (same as HP-50G+ except for colour and keyboard) to check out the display, but without the HP 48GII to compare I can't really comment on the level of black, although it does seem that I can't really make the HP-49G+ contrast darker without the whole screen being overdriven.  I noticed that there is a fairly big gap between pixels on the HP-49G+, which might be part of the problem as the light escaping between the pixels does mean that you cant really get a pure black.

 

The reflector, though seems to be better on the HP-50G than the HP-48GII, which is also a pretty important part in contributing to the overall contrast of the display with most black only LCD's. 

[aidswidjaja]

In Australia, the CASIO line of calculators has always been the most dominant and commercially successfully (which tends to be the trend in Asia) - at least in middle and high school. Generally I'm pretty happy with the layout, placement, etc mostly because the alternatives are worse. Other than that, the only real advantage for current calculator designs is that it's easy to produce and it's pretty sturdy.

 

However, I would definietly buy a pimped-out calculator with a backlit display and cherry mx blue keyswitches - could be a fun engineering project actually.

 

I actually have a HP financial calculator - 17bll+ - has some really well printed (though bare) keys with even an in-built beep speaker but most importantly - a very good tactile build quality to the keys (and it generally looks pretty nice)

[MJim]

NZ here, so I know about the Casio indoctrination, but I do have some love for Sharp.

 

The Sharp EL-W516X is awesome for the 4 formula memory storage, 4 custom key shortcuts (can be also used to assign functions from the MATH menu as well), separate store and recall buttons and of course it's best feature, persistent memory on power off.  It is however let down by terrible integration (speed and accuracy) and a fairly limited complex mode, ie storing variables in complex mode is limited to M memory, so you can't really write equations easily in complex mode on the Sharp, while it was pretty nice to work with on my Casio fx-991W (when it was working). 

 

I have my eye on the fx-991EX, but the memory loss on power off combined with an unadjustable auto-power off feature locked in at 10 minutes really bothers me (the German version (fx-991DEX) allows you to at least set this to 60 minutes; who knows what kind of reasoning was used to justify the absence of this convenience feature in the english version).

 

I have recently obtained 3 older Casio's (fx-50f, fx-550S and fx-3600PV), which happen to be the first rubber keyboard based Casio's that I own. 

 

The fx-50f seems to be a bit harder to press than the other two, with the fx-550S being very light and rather responsive.  The fx-3600PV is also a light touch rubber keyboard, and visually, I prefer the grey to the black keys with the blue coloured [RUN] button.  I also prefer the separate [Kin] & [Kout] and [x^y] buttons on the fx-3600PV, though having the [1/x], and [x^2] buttons become shifted was a mistake IMO.  The [DEC], [HEX] buttons were a waste, since they only work in Base-n mode, so I think these should of been the [ENG] buttons, which would free up another button for [x^2].  Finally [P1] and [P2] could of been moved to a single button allowing us to make [1/x] a primary function.

 

Spoiler

 

Spoiler

 

I used two pictures, since the readability of the fx-550S is greatly affected by the direction light hits it (something to do with it's polarizer at a guess, but it does make for some cool visual effects when you rotate the calculator under light), so these were taken at 90 degrees to eachother; to show how much the readability of the fx-550S LCD improves.  The fx-50f fluroescent orange printing on the calculator does appear too bright and hard to read from the photos, but does better than the fx-3600PV in more subdued lighting conditions.

 

It's pretty neat to see how much the fonts vary between all 3 of these models which all were introduced in the latter half of the eighties (1986 for fx-550S, 1987 for the fx-50F and 1989/1990 for the fx-3600PV).

Edited by MJim, 13 October 2020 - 03:22 AM.

[KamimuraCal]

However, I would definietly buy a pimped-out calculator with a backlit display and cherry mx blue keyswitches - could be a fun engineering project actually.

 

Hi, I think Casio already has something similar in its range. They advertise it as a Heavy Duty Calculator, especially the model JS-40B should meet the highest standards. It is a desktop calculator with anti-fade keys so that the labelling remains legible even after a long time. However, there is no background lighting, otherwise the energy consumption would be higher and the ecological standard would no longer be complied with.

[Hlib2]

Compared the design of the popular fx-991 series: ES and CLASSWIZ. First, we test the keyboard.

In 991ES, the main keys have optimal concavity, and their shape improves interaction under pressure. In CLASSWIZ, the concavity of the keys is reduced, the outline is made rectangular, and the bottom row of keys has a flat surface (i.e. [0] and [=] should not be as comfortable as [+] and DEL?). The ergonomics of the calculator is degraded – this is a fact.
The following image shows the quality of the labels and an abnormal design for the front surface of the gadget. Usually the relief pattern is placed on the back of the case.

I wiped the labels with an alcohol solution (never do this with calculators!) on CLASSWIZ and on the back of the case of a cheap Indian LENOVO gadget. The result is visible in the photo. The CASIO lost the test here to a little-known manufacturer.
The last photo shows the keys of an old calculator. This old technology guaranteed the readability of inscriptions for 50 years and was relatively cheap.

[MJim]

I didn't notice that the fx-991EX had flat keys for the bottom row...interesting, I wonder why they designed just that bottom row keys that way?

 

All the function keys in the top row are convex as well which I also didn't notice until now...but overall I liked the feel of the keys more than the fx-115ES Plus I used to have (though that may be more due to how loose the keys appeared to be in the case rather than the actual feel).

 

The fx-991EX has some of the worst labeling I've seen for Casio (despite how much I like it), so it doesn't improve my opinion to see how easy the labels are to wipe off with simple Alcohol.  I do appreciate the warning, as it could be something I would try myself in the future only to find I damage/destroy the labels after the fact, so thanks!

 

I have a few fx-82AU Plus calculators and they all suffer from label wear on the keys themselves.  It seems a bit cheeky that Casio is talking about key wear resistance for their newer 2nd edition series as a way to identify fakes, when they had the same problem themselves.  The plastic molded keys as you showed above have fantastic wear resistance and is something I saw on the teardown of my old Casio fx-102, but that was from 1976, so I'm not sure when this practice stopped with Casio.

 

Thanks for the post and pictures!

[Hlib2]

I compared the design of afx-2.0+ and graph100+. It is clearly visible that the case for graph100+ loses in beauty to the appearance of the
afx-2.0+. The internal circuit board with electronic components has been changed, but the other technical characteristics are absolutely the
same. In the recently purchased graph100+, a backup battery "Hitachi Maxell" of 1998 was installed. It did not leak at all, although it was 99%
discharged. This is a quality from a real company. The graphic display in graph100+ is made in the best traditions of technologies of the
mid-90s, there are no complaints about it. The quality of the keyboard is rated 4+ on a five-point scale. The chemical composition and
mechanical properties of the plastic housing are ideal, and much better than in the hp-50g, for example. IMO, this is the best calculator for both
school students and engineers, it could be produced for another 20 years in an unchanged state.

Edited by Hlib2, 05 August 2021 - 08:00 PM.

[MJim]

I'm not all that familiar with the AFX-2.0+, but from your photos I do think I prefer the colour choice for the AFX-2.0+ over the graph100+.  I think that bright yellow ink on the graph100+ wasn't a great idea and the light blue labels on the top of the function buttons are difficult to see.

 

For the display and from your photos, it looks like I would also prefer the darker black pixels of the Graph100+ over the fx-9860GII.  I'm not a fan of bluish pixels, as I like them as black as can be (though I admit that I don't mind the purplish pixels on the Sharp EL-W516XBSL, while I strongly disliked the Casio fx-115ES Plus's bluish pixels).  LCD contrast and quality is probably far more important to me then any other attribute of cosmetic design, though button feel and spacing is pretty important as well.  Something I noticed while using the Sharp EL-506P is that the smaller spacing between numbers and functions tends to speed up input time (only slightly) so it feels faster and more responsive to use even if it is only an illusion.

 

I thing out of the Graphing calculators I have, the fx-CG50 is probably the nicest looking, though the AFX-2.0+ probably has a better quality keyboard that doesn't suffer from the occasional miss or double type.

 

As for the batteries, I would think that Lithiums in general wouldn't leak, and calculators that have come into my possession that have used CR20XX type batteries seem to show no sign of leakage.  Funny enough I just got myself a Sharp EL-546 which has a nearly completely flat (several hundred millivolts I think) Hitachi Maxell CR2016 which should be from around 1987 (battery may of been replaced since then) which is also without any sign of leakage.  I've stocked up on some Maxell Silver Oxide and Maxell CR2032 Lithium batteries as I'm quite fond of the brand.

Edited by MJim, 05 August 2021 - 05:03 AM.

[Hlib2]

@ MJim

For the display and from your photos, it looks like I would also prefer the darker black pixels of the Graph100+ over the fx-9860GII.

The image of the display in the photo depends on the spectrum of the radiation source, on the quality of the camera and on some other factors. The displays in the fx-9860gii and in the graph100+ are equally good, except for the fact that the 9860gii has a parasitic backlight of off pixels when adding a contrast level (which I wanted to show in the photo).
Here are the images of the disassembled graph100+.

You may pay attention to "Datalight". This company has implemented the most stable scheme for protecting and storing data in calculators. I was convinced of this after 15 years of intensive work on afx-2.0+ calculator.

[Hlib2]

Some modern CASIO calculators (for example, fx-9860GII, graph-100+), on the one hand, have become much more reliable in terms of manufacturing quality and installation in the main circuit. On the other hand, the keyboard is made in them in the style of cheap gadgets for $5. Having disassembled the TI-v200 into its component parts, I was pleasantly surprised by the fact that these calculators do not use a cheap conductive compound for the keyboard, as, for example, in fx-2.0+ (since 2001) and in other modern CASIO calculators.

The quality of the LCD in the ti-v200 is excellent, much better than in HP calculators and in most modern classic CASIO calculators.

Otherwise, TI/HP/CASIO calculators lag behind the industry of branded devices by at least fifteen years in terms of technology. Not to mention the reliability of these supercalculators outside of office use. Even an inexpensive smartphone wins in computing tasks here in all respects, at least in terms of continuous battery life (30...50 hours) at full load. This is a very big failure in modern realities. Partly for this reason, some top-level engineers I know prefer applications in smartphones, rather than calculators with color displays such as CP400, NSpire CX or HP-Prime.

Edited by Hlib2, 22 September 2021 - 07:05 PM.

[ijabbott63]

Having disassembled the TI-v200 into its component parts, I was pleasantly surprised by the fact that these calculators do not use a cheap conductive compound for the keyboard, as, for example, in fx-2.0+ (since 2001) and in other modern CASIO calculators.

 

Yes, but they do use a cheap conductive compound on the rubber domes. I have had to repair a few with special conductive paint (that is supposedly designed not to flake off from the rubber pads).

[Hlib2]

@ ijabbott63

Yes, but they [TI-v200] do use a cheap conductive compound on the rubber domes.

I very rarely, but also encountered this problem in TI-83+/v200, FX-2.0/2.0+/9860GII, SF-5580/5780. The rubber keyboard partially lost its conductivity after a few years, even if the NIB device was not in use. This defect is absent in my TI-v200. In the electronic organizers SF-4600/4900/4980/5300/6500 etc, the rubber keyboard has been functioning flawlessly for more than 20 years, as in TI-85, FX-2.0.

I have a list of calculators
which this margin is too small
to contain.

I had a whole bag of calculators from TI, SHARP, HP, CITIZEN and CASIO. In most cases, it is either garbage or unsuccessful technical solutions. I have no regrets about the FX-6300g/4500/3600PV, SRP-175/320g/325g/400g, TI-82/92/95, HP-39gs/39gII/49g, EL-9400/9450 and several other models of calculators. They are not worth analyzing in detail their shortcomings. Tell us about some of the best calculators that you are well versed in. Personally, I am not interested in reading a long tape of models that have no meaning either for modern engineers or for students.

[Hlib2]

This is a kit with a branded "power bank" (not Li-ion or Li-polymer technologies, I have not yet studied this battery in detail). The battery charge for the calculator is enough for more than one year. The full capacity of each power bank is 12 000/20 000 mA×h respectivly, the actual operating capacity according to the manufacturer`s specifications is 6 300/12 300 mA×h at 1A. The lower the current consumption of a device, the greater the actual battery capacity for this discharge mode. And vice versa.
For example, at a discharge current of 0.2 A, the batteries produce a capacity of approximately 8 500/16 000 mA×h at +20°C during one discharge cycle at a constant temperature accordingly. The permissible temperature range for the battery: -25°C ...+20°C ...+65°C. Self-discharge losses: 5% ... 15% ... 40% per year, depending on the temperature.

I intentionally removed the logo on the device body. The reputable company can order its own product with specific technical requirements under any beautiful name in China (for example, a primitive scientific calculator with an alarm clock called "Super Math plus / sound-2 silver edition" :-) ) etc.
EDIT : specification of the technical characteristics of the cheap "power bank".

Edited by Hlib2, 29 September 2021 - 06:02 PM.