Casio’s blunder? Or not?

[Matt Agajanian]

Hi.

Has anyone seen this:

Casio’s apology

Yes, I know it’s been decades. What has progressed since this?

[Steve Simpkin]

I wonder what “calculation mistakes” they found?

[Albert Chan]

There is no legal recourse even if serious bugs exist.
It is in all Casio manual. (not liable for any claim of any kind, whatsoever ...)

Apology is just a save face response, nothing more.

Anyway, "fix" is to revise user manual ... bug should not be serious.

[Alder Statesman]

(06-08-2024 11:49 PM)Steve Simpkin Wrote:  I wonder what “calculation mistakes” they found?

Interesting as per the article the error was discovered and reported in 1996 for calculators manufactured in 1998. Flux capacitor issue?

[Matt Agajanian]

(06-09-2024 01:51 AM)Alder Statesman Wrote:  

(06-08-2024 11:49 PM)Steve Simpkin Wrote:  I wonder what “calculation mistakes” they found?

Interesting as per the article the error was discovered and reported in 1996 for calculators manufactured in 1998. Flux capacitor issue?

Maybe it couldn’t handle 1.21 ‘jiggawats’ of power.

[EdS2]

Interesting... the article says that an update to documentation would suffice.

So we can check the documentation we find, presume it to be the corrected version, and see what looks suspicious...

There's a PDF manual here. I see a few notes in the section on integration which might be relevant

Quote:Note:
For a function f(x) whose variable x cannot take the zero value, input an appropriate number in between steps 1) and 2) above
Do not use constant registers, KAC, ENT, and HLT during expressing a function (step 4).

Also a couple of pages later some Remarks

Quote:Remarks for execution of integrals
- If you press AC during execution of integral (nothing is displayed). the execution will be aborted and the state selected by the depression of MODE 1 entered.
- If no function f(x) is defined (written in), the calculator will carry out integral for f(x) = x.
- It is normal to set the angular mode to R when executing integral of trigonometrics.
- Integral approximated by the Simpson’s rule may take much execution time to raise the accuracy of result. Error may be large even when much execution time has been consumed. If the number of significant digits of result is smaller than one, error termination occurs ("-E-" displayed)
In such cases, dividing the integral interval will reduce execution time and raise accuracy:
1. If the result varies greatly when the integral interval is moved slightly: Divide the interval into sections and sum up the results obtained in the sections.
2. For a periodic function or if the value of integral becomes positive or negative depending on the interval: Calculate for each period or separately for the sections where the result of integral is positive from where the result is negative, and sum up the results obtained.
3. If long execution time is due to the form of the function defined:
Divide the function, if possible, into terms, execute integral for each term separately, and sum up the results.

[xerxes]

(06-08-2024 11:49 PM)Steve Simpkin Wrote:  I wonder what “calculation mistakes” they found?

One of those "calculation mistakes" on the FX-3900PV regards the power function:

2^31 gives 2147483647
2^32 gives 4294967295
2^33 gives 8589934589

[Thomas Klemm]

(06-09-2024 07:12 PM)xerxes Wrote:  2^33 gives 8589934589

(08-13-2018 03:58 PM)Thomas Klemm Wrote:  So I tried to maximise the duration by using \(2^{33}=8,589,934,592\) but was slightly disappointed by the result:
Only disk 5?
Whereas I've expected 34.

Turned out the given result was \(8,589,934,605\) which is off by \(13\).
So I've entered the correct value manually.

Thus, in the years since the advent of the HP-25 they managed to bring the error down to 3.

[thenozone]

As a matter of interest, my Casio fx140 , was getting 2^23 calculated incorrectly in 1978 ( or was that 1976), but not by much. see photo.

[toml_12953]

(06-08-2024 11:22 PM)Matt Agajanian Wrote:  Hi.

Has anyone seen this:

Casio’s apology

Yes, I know it’s been decades. What has progressed since this?

Bill and Dave would've replaced all the defective calculators for free. In fact, they did make that offer for one bug in the HP-35.

[Matt Agajanian]

(06-12-2024 05:06 PM)toml_12953 Wrote:  

(06-08-2024 11:22 PM)Matt Agajanian Wrote:  Hi.

Has anyone seen this:

Casio’s apology

Yes, I know it’s been decades. What has progressed since this?

Bill and Dave would've replaced all the defective calculators for free. In fact, they did make that offer for one bug in the HP-35.

Yes. I remember that. Although only a few were returned, though.

[Steve Simpkin]

(06-12-2024 05:06 PM)toml_12953 Wrote:  

(06-08-2024 11:22 PM)Matt Agajanian Wrote:  Hi.

Has anyone seen this:

Casio’s apology

Yes, I know it’s been decades. What has progressed since this?

Bill and Dave would've replaced all the defective calculators for free. In fact, they did make that offer for one bug in the HP-35.

Dave would have also pulled new calculators out of the warehouse, pulled them out of their sealed retail box and fixed them before selling them to the public if there was even a relatively small bug in them. This is exactly what happened with the first production run of the HP-27.

Professor William Kahan recalls his role in this small part of HP history and gives yet another example of why HP (and particularly Bill Packard) were so highly regarded back then.

"The first calculator that was doing what I said they should do was the HP-27, and they sent me a prototype that I could play with to see whether things were working out the way I said. Things were working out the way I said they would. The functions really did look a lot better. In fact, Dennis Harms actually wrote a little paper, I think, that got published in The HP Journal somewhere. But I was puzzled because on the top row of the calculator’s keyboard, they had these five keys: n, i, PV, PMT, and FV. I said, “And what do they do?” “Oh,” they said, “you don’t have to know that.” It was on a need-to-know basis, you see. So I looked at these things, and I finally figured out what they were doing. These for calculating the relationship among the interest rate, the initial loan value, a regular payment, like payment on a mortgage—the balloon payment, and the number of payments all totaled. That’s what it was supposed to do. It didn’t take me long to figure that out. I mean, after all, I had attended an actuarial science course in which such things were discussed, even if I had read in the back of the class. Then I said, “You know, if they’re going to compute the interest rate, that’s a non-trivial computation. I wonder if they can get it right.” And, of course, they couldn’t. So there were cases where I could see that, although it’s a ten-figure calculator, they’ve only got six figures correct of the interest rate. It didn’t take me long to find that.

And I phoned my contact at Hewlett-Packard. I said, “Listen, I figured out what you’re doing here, but I’ve got to tell you, you’re losing digits. I’ve got this very simple example. It took me only a few moments to construct, and your interest rate is good to only six figures.” And the guy said, “Well, that’s okay; all we need is six figures.” I said, “Look, you’re going to lose more.” I found an example, and I called him up, and I said, “Look, here’s an example where you’ve lost all but four of your figures, and if you want to give me longer, I’ll find some where you lose them all.” But the fact that he had only four figures correct, that started to worry him. And I could hear the tone of his voice change—there were pauses. Then I said, “But you know, there is a way to do this that’ll get it right. And furthermore, it will liberate you from one of the constraints that you’ve put on the input data I see. That’s an unnecessary constraint.” And I described the algorithm to him, and then I sent him something.

Yes, he microcoded it up, and he found the calculator worked faster for these interest rate calculations. The answer was just fine, right out to the last digit. And it didn’t have this unnecessary restriction, and everything about this was just marvelous except for one thing: they already had a warehouse full of these calculators in cartons with their manuals, ready to hit the Christmas market. What should they do? I was invited to a meeting, and David Packard was at the head of the table of this meeting. I didn’t have much to say. I didn’t have to because my views were being represented by one of these guys who said, “Our consultant found a bug. The bug appears to be serious. We found a way to repair the bug; the consultant provided that. All we have to do is replace ROMs. Unfortunately, that means we have to unsolder the old ROMs and solder new ROMs in. You can’t just do a plug-in, but we’ve got tools for doing that. What are we going to do with the thousands of boxes? Should we put them out on the market and insert a little slip into each one saying, ‘Sorry, there’s a little glitch, and if you send your calculator back, we’ll fix it’?”

And David Packard said, “No, we’re not going to sell a defective product. It’s one thing to put them out on the market when we didn’t know there was a defect, and then later we have to chase down people. It’s something else to sell something when we know it’s defective.” And he said, “We will withdraw the calculators from the warehouse. We’ll make the necessary fix, change the ROMs, and so on. So we won’t make the Christmas market. We’ll have to go for the Easter market,” so to speak, or some other subsequent market. That shot my respect for David Packard up several notches. Now I knew he was a good guy. I knew he was technically competent. I knew that he ran a company based on what I would have to call humane principles. It wasn’t just good business. It was broadly humane. But he didn’t delay in that decision. It wasn’t as if it was an agonizing decision. It was clearly the proper decision. He made it there in my hearing, and I have to tell this story because there aren’t very many people who know it. And if you wonder why David Packard had earned the respect of so many of the people who knew him, this is another one of those stories. But in the meantime, I was in. From now on, I was participating in these calculators. That was all being done down in Cupertino. The next big task was going to be the HP-92."

Professor William Kahan's full oral history PDF document can be found at the following link. His history with HP starts on page 144. The story regarding the HP-27 starts on page 147.
https://drive.google.com/file/d/1Jlg9EWQ...sp=sharing

[Matt Agajanian]

Hi. Too easy that the little buggy calculator mentioned in the article was the HP-35 (that nasty ln 2.02 rascal). The later point that William Kahan found the HP-27 glitch and the calc was delayed raises the question—if the 27 was in the hands of an outside user who then found the financial glitch, why wasn’t the 35 given the same testing or an outsider willing to test the 35 before it went to market? Or was the 35 tested and used by an outsider before it was commercially available?

[Steve Simpkin]

(06-12-2024 11:44 PM)Matt Agajanian Wrote:  Hi. Too easy that the little buggy calculator mentioned in the article was the HP-35 (that nasty ln 2.02 rascal). The later point that William Kahan found the HP-27 glitch and the calc was delayed raises the question—if the 27 was in the hands of an outside user who then found the financial glitch, why wasn’t the 35 given the same testing or an outsider willing to test the 35 before it went to market? Or was the 35 tested and used by an outsider before it was commercially available?

Remember that William Kahan was a consultant for HP so he was, for all intensive purposes, a part time employee of HP. He was also an exceptional mathematician with an incredible talent for finding bugs. HP hired his services for this purpose (and more).

I recall reading that HP showed prototype HP-35 models to individuals but I don't know if they ever had "beta testers" outside of HP employees. The general reaction to seeing the prototype HP-35 was similar to this.

“I remember when Fred Terman got his sample HP 35, we made about six prototypes, he just couldn't believe it, kept looking for the cable. Louie Alvarez called it the ‘eighth wonder of the world.’ Having an HP 35 in the early days meant you could attract attention without having to know how to play the piano, but mostly you got all the men hanging around you at cocktail parties.”

The HP-35 Story, From "Inside HP,"

[Matt Agajanian]

Thanks, Steve for that flashback! Truly mesmerizing and fascinating. Good thing I got a copy from the link. I’m glad I could add it to my library!

Much appreciated.