Talk:HP 35s

Left and Right Shift Keys
Is it just me, or are the arrows on the left/right shift keys pointing the wrong way? The blue key has an up-then-right arrow, but the blue labels on the keys are down and to the left. The gold key has an up-then-left arrow, but the gold labels on the keys are all either straight up or down and to the right. Guy Macon 19:13, 29 September 2010 (UTC)


 * The HP-50G has a white up/left arrow pointing to the white labels on the upper left of each key, and a red up/right arrow pointing to the red labels on the upper right of each key. See


 * http://www.geocalc.com.au/files/2011760/uploaded/HP50G-SDcard2.jpg


 * The HP-15C,which the HP-35S keys are clearly modeled after, has a gold "f" key that selects the gold labels above each key and a blue "g" key that selects the blue labels on the lower face of each key.


 * http://www.thimet.de/calccollection/calculators/hp-15c/HP-15C-M.JPG


 * Clearly the designers of the HP-5S copied the shift keys from a HP-50G (or an earlier member of that series) without thinking about what the arrows are supposed to mean. Guy Macon  10:54, 3 October 2010 (UTC)

Trig errors
Here are some results of math done on a HP 35S compared with what the displayed result should be. I am presenting it here so that other editors can use it as a guide when doing research to find citations.

sin(1E-1): 1.74532836590E-3 Answer SB: 1.74532836590E-3 (correct) sin(1E-2): 1.74532924306E-4 Answer SB: 1.74532924313E-4 ^^ sin(1E-3): 1.74532925091E-5 Answer SB: 1.74532925191E-5 ^^^ sin(1E-4): 1.74532925000E-6 Answer SB: 1.74532925199E-6 ^^^ sin(1E-5): 1.74532920000E-7 Answer SB: 1.74532925199E-7 ^^^^ sin(1E-6): 1.74532900000E-8 Answer SB: 1.74532925199E-8 ^^^^^ sin(1E-7): 1.74532000000E-9 Answer SB: 1.74532925199E-9 ^^^^^^ sin(1E-8): 1.74532925199E-10 Answer SB: 1.74532925199E-10 (correct) sin(1E-9): 1.74532925199E-11 Answer SB: 1.74532925199E-11 (correct)

Quote:

"'The [original] HP-35 had numerical algorithms that exceeded the precision of most mainframe computers at the time. During development, Dave Cochran, who was in charge of the algorithms, tried to use a Burroughs B5500 to validate the results of the HP-35 but instead found too little precision in the former to continue. IBM mainframes also didn't measure up. This forced time-consuming manual comparisons of results to mathematical tables. A few bugs got through this process. For example: 2.02 ln ex resulted in 2 rather than 2.02. When the bug was discovered, HP had already sold 25,000 units which was a huge volume for the company. In a meeting, Dave Packard asked what they were going to do about the units already in the field and someone in the crowd said 'Don't tell?' At this Packard's pencil snapped and he said: 'Who said that? We're going to tell everyone and offer them a replacement. It would be better to never make a dime of profit than to have a product out there with a problem.''"

Source: http://www.hpmuseum.org/hp35.htm

Guy Macon 21:09, 13 November 2010 (UTC)

File:Hp35s Calculator.jpg Nominated for speedy Deletion
I just emailed the author of the web page and asked him for permission.

Here is what I wrote:

"Hi! I am an editor over on Wikipedia.

Our article on the HP-35S ( http://en.wikipedia.org/wiki/HP_35s ) has an image that appears to be from your website.

See http://commons.wikimedia.org/wiki/File:Hp35s_Calculator.jpg for details.

We are about to remove the image for copyright violations.

Is this what you want, or would you prefer to give permission to use it?

If you decide to allow Wikipedia to use it, you can either say that you are making it public domain or that the image is licensed under the Creative Commons Attribution ShareAlike 3.0 License (See http://creativecommons.org/licenses/by-sa/3.0/ for details).

If you decide not to give permission, we will remove the image at once, and I apologize that someone uploaded it to Wikipedia without permission.

You can view my Wikipedia pages at http://en.wikipedia.org/wiki/User:Guymacon and http://en.wikipedia.org/wiki/User_talk:Guymacon "

--Guy Macon (talk) 22:34, 26 July 2011 (UTC)
 * Good move. Hope it works, because it's a nice picture. Rwxrwxrwx (talk) 23:02, 26 July 2011 (UTC)


 * I received two email replies from the author (Stefan Vorkoetter). They said:


 * "Hi, thanks for writing. Yes, by all means, use it. As a matter of fact, I'm pretty sure it was I who uploaded it in the first place a few years ago (I might have forgotten to log on). Perhaps I forgot to mark it as free for use. The Creative Commons license sounds like a good idea."


 * and


 * "Hi again. Looks like it wasn't me that uploaded it, if I'm interpreting the history correctly, but yes, please put it under the CC license.


 * I'm curious, how did this copyright violation get discovered? Did some automated tool find it, or did someone report it?"


 * Does anyone know how this was discovered? Guy Macon (talk) 01:31, 27 July 2011 (UTC)


 * I discovered it (look at the page's history). The author's site is linked from this article and when reading it I thought the picture looked very similar and it turned out identical. The site has a note at the bottom expressly forbidding unauthorised use of content, and it was created before the file was uploaded here, and the uploader seemed to have a history (at that time) of uploading copyrighted content. The author appears to be running the site as a hobby, and his photos are the highest quality, and people are not entitled to simply lift his content at will, so I followed what seems to be the standard procedure. Well done on taking the initiative, which has turned out well. Rwxrwxrwx (talk) 09:28, 27 July 2011 (UTC)


 * RESOLVED: OTRS permission confirmed as of 17:23, 2 August 2011. Guy Macon (talk) 09:07, 3 August 2011 (UTC)

Indirect branching
The article says that
 * Indirect branching, which allows the contents of a memory register to be used as the target of a branching instruction (GTO or XEQ) is available in the HP 33s, but was omitted from the HP 35s.

However, in the user guide http://h10010.www1.hp.com/wwpc/pscmisc/vac/us/product_pdfs/user_guide.pdf on page 14-20 it is mentioned. Does it behave differently on the 33s from the 35s ? I don't quite agree with the term "omitted". --Bram4 (talk) 20:19, 11 December 2011 (UTC)


 * Good catch! I just put a citation Needed tag on that statement.


 * I am soooo tempted to pull out my HP 35s and do some original research, but I am going to be a good boy and look for citations instead.


 * http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv017.cgi?read=119634 says that the manual is in error.


 * http://www.freak-search.com/en/thread/874150/hp-35s_indirect_branching agrees that the manual is in error.


 * ...but those are blogs / discussion groups, which are nor reliable sources. But here is a reliable source:


 * http://h20331.www2.hp.com/Hpsub/downloads/35_08_Using_index_registers.pdf


 * With a section titled "differences from the 33S." I haven't read it in detail yet, but it looks liken it might have our answer. --Guy Macon (talk) 00:00, 12 December 2011 (UTC)

Square roots of negative numbers
Among the calculator's idiosyncrasies with complex numbers, the article mentions:

"For example, directly taking the square root of a negative real number results in an error message instead of a complex number. This is strictly correct given that a nonnegative real number a has a unique nonnegative square root and this is called the principal square root which is denoted by √a."

I think this is bending over backwards to supply excuses. While the statement doesn't finish spelling out its argument, implicitly the writer seems to regard something as indeterminate about the roots of negative or complex numbers -- but the second sentence would appear to undercut the argument, by needing to qualify (with "nonnegative") the uniqueness of a root for a nonnegative number as well.

That is, any number -- complex, or positive real either -- has two square roots and you have to say which one you'll regard as principal -- but given that, it's common to define a unique principal square root for negative and complex numbers too. (The convention being about the same one as above, actually: the root with the nonnegative real component. See Wikipedia's article on "principal square root," for example.)

What a calculator's for is to get work done, not to split hairs about number theory. If there were a bona fide practical ambiguity, then one should be careful, but there isn't. And the HP42s, and Hp48g, have no trouble responding with the principal value of roots for complex numbers, including directly taking the square root of a negative real number. 64.222.209.201 (talk) 19:41, 16 February 2019 (UTC) 64.222.209.201 (talk) 19:46, 16 February 2019 (UTC)


 * I think 64.222.209.201 makes a good point. Does anyone object to me removing the "This is strictly correct..." language and adding "this behavior is not found in other HP calculators"? --Guy Macon (talk) 21:23, 16 February 2019 (UTC)