Yes, calculators are made from plastic ^^

[Stefan]

Here is a PCB shot of the Casio fx-991DE-Plus I took a while ago.
(I am actually not sure whether this is the DE-Plus or the ES-Plus, because the PCBs are the same.) I guess they only differ in the chip under the black resin. Gosh, I would love to know whether there is a hidden JTAG port or similar under the resin and whether they used some rewritable program memory :-D
The PCB in the Casio is also fixed with these molten plastic domes to the front. I removed them with a knife, but there is nothing interesting on the front side of the PCB.

One thing which would interest me: Does the HP-300s+ also gets rather unresponsive with big expression? For example hit 10 times the sqrt key and then type 111111 (or any other digit) rather fast, then the casio only catches 111 or so. I find that extremely annoying, and can be uncomfortable in exams when time is short.

The 300s+ PCB looks much more clean than the one in the Casio. It's funny, because the 300s+ is actually ~5$ (or ~25%) cheaper than the Casio. Also the HP has large ground (or VCC)planes everywhere, whereas the Casio has just empty space. Also look at the vias on the casio: On the casio they are made from the same black resistive material as the button sensing areas on the front of its PCB
The HP uses metal vias and metal sensing areas for the buttons (as one can see at the reset button which is on the back of the HP)

[jebem]

Nice photo of the Casio, Stefan.

1) Concerning the Casio missing key entries:
On my HP-300s+ I just took now the sqrt of sqrt of sqrt of sqrt of sqrt of sqrt of sqrt of sqrt of sqrt of sqrt of 11111 and after about 5 seconds the cal gave the result = 1.009138861.
Tried several times and never lost a single key entry.
Oh, and I'm not using the cell battery, just the solar panel for that.

2) On my HP-Prime, i did the same calculation as above (10 x sqrt of 11111, and the answer was immediate with the result = 1.00913886108.
This is really a beast of a calculator, no matter what others can tell. Buggy and picky maybe, but still an amazing machine.

3) Concerning where HP is sub-contracting the manufacturing of their calculators, let me add one more observation:
- Looking to the HP-300s+ PCB we see the reference "Juniper EA-631".
- Looking to the HP-Prime Logic PCB we see the reference "EA656 MB"
- Looking to the HP-Prime Diagnostic menu, we see EA656 in the title...
So this "EA" prefix in both HP calculators PCB is not a coincidence.
Now, both of them has a print in the back saying "Made in China".
And it seems that both were made by the same Chinese manufacturer.
And everybody says it is Kinpo Electronics, but there is no proof of that.

I have here a Casio Algebra FX 2.0 Plus and it says "Made in China" as well.
So Casio Japan doesn't make calculators anymore, they do the same as HP, just sub-contract one expert elsewhere to do the job.

[Steve Simpkin]

Did the same multiple 10 x sqrt of 11111 test (quick presses) on a Casio fx-115ESPlus and a Sharp EL-W535X. Neither calculator lost any keystrokes. Interestingly the cheaper Sharp model ($10US) took about 1 second to come up with the answer vs 3 seconds on the more capable and expensive ($17US) Casio model.

[Stefan]

After reading in one of the previous posts about Kinpo I found this "Calculator forensics" website pretty interesting.
I did the calculation on my calculators:
Casio fx-991DE+ (same result as the ES+): 9.000 000 007 333 38
Casio fx-991MS: 8.999 998 637 04
Sharp EL-W506: 9.000 000 015 012 4
TI NSpire CAS (approx): 8.999 999 981 769 1
HP Prime (Home Mode): 8.999 998 642 67
HP Prime (CAS Mode, approx): 9.000 000 005 914 387 202 210 498 285 469(...?)

Maybe you can do the same on the HP300s+. If its the same result as for the 991DE+, then this coul be a hint that they are made by the same manufacturer (Or that the developers learned the CORDIC algorithm from the same professor ;-) )

Good to know that the HP doesn't have the problems with the slowliness of the entry. So then I would say the HP300s+ and the Sharp EL-W506 are the best 15...20$ scientific calculators out there. Too bad that the HP doesn't have these user programmable keys like the Sharp does. I really love this feature. But therefore it has gcd, lcm and prime factoring functions. I wonder whether there will ever be "the perfect calculator"? :-D Can't be that hard, right?

[Stefan]

(02-23-2014 12:57 AM)Steve Simpkin Wrote:  Did the same multiple 10 x sqrt of 11111 test (quick presses) on a Casio fx-115ESPlus and a Sharp EL-W535X. Neither calculator lost any keystrokes.

Did you have it in "Math2D" mode (this "natural display" mode)? My 991ES-Plus does definitly loose keypresses. This key-press-loosing is also frequently mentioned in reviews about the calc.
Maybe use even more sqrts to produce the lag.

Edit: My Sharp EL-W506 also gets somewhat slower when I enter a *lot* of sqrts, but it is far from being a real problem. The Casios however show this behaviour even with relatively few sqrts so that it can be a real problem.
(Note that this problem is not only with sqrts, I just use them as an example because they are easy to type. The problem occurs with every expression which is "graphically intense", because the calc has to recalculate the entire screen (that is the official answer from the Casio support).

[jebem]

Done.
The savage test on the HP-300s+ gives = 9.000 000 001 nice result, but different from the Casios...

[Stefan]

Can you also find out the Guard digits, as described here?: http://www.rskey.org/~mwsebastian/miscpr...digits.htm
(Basically by subtracting 9 from the result and multiplying by 1000000. This pushes the guard digits to the front). You can look in the list on the linked webpage which (or if) calc produces the same results.

[jebem]

done.
entry: (sin^1(cos^1(tan^1(tan(cos(sin(9))))))-9)*1000000
result: 0.000881497

[Stefan]

Hehe, this even beats the Prime by one digit ^^.

[Steve Simpkin]

(02-23-2014 01:09 AM)Stefan Wrote:  Did you have it in "Math2D" mode (this "natural display" mode)? My 991ES-Plus does definitly loose keypresses. This key-press-loosing is also frequently mentioned in reviews about the calc.
Maybe use even more sqrts to produce the lag.

Yes and the 115ES Plus did a good job of updating the display while I was quickly pressing the sqrt key. With a bit more testing I found it did miss key presses but only if I pressed them really quickly. I did not see any missed key presses when I pressed 10 sqrt's, 5 ones and "=" (16 keys) in about 5 seconds. When I sped up and pressed them within approximately 4-4.5 seconds it would sometimes only register 3 or 4 of the ones instead of 5. This seems very responsive to me, at least with this sequence.

[Joe Horn]

(02-23-2014 01:02 AM)Stefan Wrote:  HP Prime (CAS Mode, approx): 9.000 000 005 914 387 202 210 498 285 469(...?)

To be precise, Prime's CAS returns exactly 9.00000000591438720221049152314662933349609375
which is stored internally as exactly 1.200000032CDEp+3
which is also representable exactly as 158329674503791 / 2^44

I know that you were just dying to know that.

[Thomas Radtke]

(02-23-2014 12:23 AM)jebem Wrote:  I have here a Casio Algebra FX 2.0 Plus and it says "Made in China" as well.
So Casio Japan doesn't make calculators anymore, they do the same as HP, just sub-contract one expert elsewhere to do the job.

I think it makes a difference to what degree a particular calculator design has been outsourced. Especially the firmware should be done by the company selling the calculator (like in the Prime, unlike in the 35s), else one could quickly come to a point where the basic stuff is more or less the same in all products, including bugs. In the extreme, the manufacturer can only be told by the label on the package (e.g. HP-30S).

There's one interesting observation: Kinpo calculators work like early Casio calculators in terms of user interface and labelling. They also produce (musical) keyboards for Casio and probably other devices, too. Do Kinpo belong to the Casio group of companies? I'd really like to know more about this topic.

Edit: Ha, there's the Google translator! According to the history page of Kinpo (http://www.kinpo.com.tw/English/about_history.html), their calculators are made since 1996.

[HP67]

I note most of the middle to high-end calculators today regardless of brand seem to have the same physical layout with shift and arrow keys all in the same place. Look at the 50g and then look at the TI-84 and 89 and some Casios. Kinpo sure does make a good business out of selling the same stuff over and over again under different labels! What do calculators and anti-freeze have in common? ;-)

[Steve Simpkin]

There is a good comparison between the SHARP EL-W516 and the CASIO fx-115ES calculators at:
http://members.bex.net/jtcullen515/Math8.htm

More than a simple comparison, the two volumes presented here (175 pages) are also a good tutorial on how to use these models. The information is usable for newer Casio and Sharp scientific calculator models as well.

[HP67]

Thanks for the links!

[Lonewolf]

   

(02-23-2014 01:02 AM)Stefan Wrote:  After reading in one of the previous posts about Kinpo I found this "Calculator forensics" website pretty interesting.
I did the calculation on my calculators:
Casio fx-991DE+ (same result as the ES+): 9.000 000 007 333 38
Casio fx-991MS: 8.999 998 637 04
Sharp EL-W506: 9.000 000 015 012 4
TI NSpire CAS (approx): 8.999 999 981 769 1
HP Prime (Home Mode): 8.999 998 642 67
HP Prime (CAS Mode, approx): 9.000 000 005 914 387 202 210 498 285 469(...?)

Maybe you can do the same on the HP300s+. If its the same result as for the 991DE+, then this coul be a hint that they are made by the same manufacturer (Or that the developers learned the CORDIC algorithm from the same professor ;-) )

Good to know that the HP doesn't have the problems with the slowliness of the entry. So then I would say the HP300s+ and the Sharp EL-W506 are the best 15...20$ scientific calculators out there. Too bad that the HP doesn't have these user programmable keys like the Sharp does. I really love this feature. But therefore it has gcd, lcm and prime factoring functions. I wonder whether there will ever be "the perfect calculator"? :-D Can't be that hard, right?

Can I ask, what would be your idea for a 'perfect' scientific calculator? One of my pet peeves is that not only do all Casio scientific calcs place pi as a second function key, Casio places it at the very bottom of the keypad; very irritating. . . My TI-36X II has pi (and EE) as a first-function key, as God intended.
/Silicon Valley Regards

[walter b]

(08-25-2014 08:38 AM)Lonewolf Wrote:  Can I ask, what would be your idea for a 'perfect' scientific calculator?

Well, perfect scientific calculators (PSC) are a long story. Not as easy to agree on as on a perfect wheel. Please just let me point you to the fact that we offer 2.5 approximations to a PSC: The WP 31S (featuring a primary pi), the WP 34S, and the 43S. You find plenty of information about them on this very forum. Enjoy!

d:-)

[Bill Zimmerly]

(08-25-2014 08:38 AM)Lonewolf Wrote:  Can I ask, what would be your idea for a 'perfect' scientific calculator?

The body of the HP-Prime and the soul of the HP-50G (RPL).

(Body == hardware, Soul == software)

[Lonewolf]

(08-25-2014 09:18 AM)walter b Wrote:  

(08-25-2014 08:38 AM)Lonewolf Wrote:  Can I ask, what would be your idea for a 'perfect' scientific calculator?

Well, perfect scientific calculators (PSC) are a long story. Not as easy to agree on as on a perfect wheel. Please just let me point you to the fact that we offer 2.5 approximations to a PSC: The WP 31S (featuring a primary pi), the WP 34S, and the 43S. You find plenty of information about them on this very forum. Enjoy!

d:-)

I appreciate your reference to the WP-series of scientific calculators; I want to be more specific. . . Whether RPN or algebraic, a 'perfectly' designed scientific calculator for the non-professional (since it's doubtful manufacturers will ever create them again as in the days of the 1970s and 1980s) would be one that would have all of the first-functions, as space allows, that are very important to non-professional scientific use:

1. 1/X; pi; DMS; EE; ENG; DRG; sqrt; x^2; sin; cos; tan; log; ln; y^x; STO; RCL; Ab/c; Rec>Pol

Relegating the trigonometric HYP button to a second-function would free up a first-function button.

And all of this would be in a package no longer than 5-3/4". You would pick up this handy, elegant scientific calculator with an organized keypad, efficiently perform common calculations with minimum keystrokes, and it would have soundness in its mechanical design.

Do you share similar concerns in scientific calculators?
/Silicon Valley Regards

[Lonewolf]

(08-25-2014 12:25 PM)Bill Zimmerly Wrote:  

(08-25-2014 08:38 AM)Lonewolf Wrote:  Can I ask, what would be your idea for a 'perfect' scientific calculator?

The body of the HP-Prime and the soul of the HP-50G (RPL).

(Body == hardware, Soul == software)

Are you thinking of, for professional use?

/Silicon Valley Regards