I have a hp 39G and wish to enable Cas. Does any one have or know where can get the enabling applet?


AFAIK that is not possible. If there is an IR port CAS is disabled. That would be a "big big easter egg" if I am wrong.



I think Jordi did write an applet that enables the CAS on the 39G. I seem to remember it does not work on the 39G+.
I guess hp would not be very happy if this applet was distributed.



Speaking about the Hp40G to clarify.

CAS allows you to have the Eq Writer, which is not active on the Hp39G.

But you can do symbolic manipulation with the Hp39G without enabling the CAS. You work with variables S1-S6 and use them in place of a normal a-z variable.

CAS does give you an Eq Writer which is one of the best features of the HP40, 48 or 49. You do get to show your eq on the screen of a 38/39, but you need to enter it in correct format on line entry, then show. It will then display the work in textbook format.

The Hp39G is certainly at bargain rates on ebay. And it is a big step up from a Ti-83/84 for math features. Unfortunately, it is algebraic only and has the infamous RUBBER keys. Still a good number cruncher though at a great price.

AND if anyone ever develops an RPN applet for the 38/39 series, it may add another good quality RPN basic calculator to the mix (the Hp38G anyway, kinda ugly, but a true Hp quality keyboard).


Mike is right: one cannot have both IR and CAS at the same time. That's why my aplet works as a toggle. (BTW, the correct spelling, however odd it may seem, is indeed 'APLET' which stands for Animated Personal LEarning Tool. See Datafile V14N2p6). My aplet is not the only way of enabling the CAS, though.

Ron, "CAS" allows you to have the EQW and about 200 CAS commands, many of which are not usable in the EQW.

Now that the 39G has been discontinued, I guess it's only a matter of time before it all comes out. Exactly how much time is needed depends on how soon the 39G, which is still widely used in WA, will be replaced by the 39G+.

Anyway, I've always found it a banal secret. ;-)



Hi Jordi!

An other question: I have 3 different ROM files here that work well in Emu48, two of them are 4MB in size. Is there somewhere a note published about the differences?



There's only one production 39/40G ROM version ("A1.40" --
the ROM can be uploaded using this aplet by Christoph Giesselink). An earlier beta version was released for evaluation. I think it's the one in this file (for the YorkeM emulator) and this one (for Emu48). IIRC, there were few bug reports, so there can't be many differences (all betas released after March 29th, 2000 share the same supported entry point list). And see also this post. Remember that there's also a flash file for the 49G to emulate the 39/40G. Hope this helps!

Regarding the CAS enabler aplet, it seems that the aplet (or at least its existence) is now becoming public knowledge in Western Australia, despite the precautions taken. In fact, a copy of the aplet was handed out (!!) at the State Conference MAWA 2004 (page 3) ... May I remind them that it is postcardware :-) Here are some reactions to the aplet: see page 10 of this PDF, page 3 of this one, and page 2 of this other paper. And see also http://members.iinet.net.au/~ccroft/faqs_70-79.htm#79. Fortunately, the aplet can be easily detected (it can't be renamed) and deleted from the calculators of
cheating students ;-)



Hi Jordi,

What is this about a 39g and a 40G? Are they actually the same machine but different? (Because they were not RPN I did not look at them in the past...but I am now a changed man, and I will even look at algebraic machines :^). Was the 39G sold in Austrailia only? What is this CAS controversy---you mean Austrailian academia (prudently) believes that high school students should practice their algebra skills at all opportunities, while US academics believe in machines? What's going on? (I am getting too old to be in the loop, but my 7 year old is getting older all the time...).




Jordi developed an enabler that is rumored to make the Hp39G into an Hp40G. And since Jordi is now providing proof positive of his excellent work, you used to be able to get a copy of his enabler by sending him a postcard with your email address and he used to graciously send a working version of his enabler (I suspect he still does, but I don't want to make commitments for him).

This has been a behind the scenes secret that Hp did not want to leak out and probably unfairly got Jordi to agree to keep silent about. Now that the new 39G+ is in reality an 39G - (they cut something off err out). Hp did not want their Hp39G banned from exams (ACT banned it already and SAT doesn't care).

That said, you can buy an Hp39G off of ebay for peanuts and get a CAS enabler that effectively makes the 39G rival the Casio FX 2.0. Mathematically, it makes it on par with even the Ti-89 (there is more to a graphics than math horsepower, and the Ti-89 will blow an Hp39/40G away in all else).

But the Hp40G (or 39G with enabler) is a very simple calculator to use as flag settings aren't there to mess up. The screen is cleaner with no clutter and with only 27 variables, any variables are instantly assumed to be implied multiplication. And only with the CAS do you get the Eq Writer vs doing without on the standard Hp39G.

Sadly, the Hp39G has the rubber keyboard and no RPN aplet available. It suffers from the same afflictions as the Hp49G.


Yes, Sir, this helped a lot!!!



Hi all!

If you like the HP-40G you probably like it's emulation on a PC too. Maybe you find my skins colored in grape-green and peach flesh usefull, see http://ourworld.compuserve.com/homepages/nutem/pioneer.htm

Well. I just saw that the "queezed HP-40G" skin is too dark on a CRT, on a laptop's LCD the black keys show clear on the dark blue surface. I'll fix that ASAP <G>



i think the cas enabler applet should be aloud to be downloaded off the net. If Jordi says its easy to detect on the calculator then there should be no problem with cheating student. I am currently studying mechanical engineering and have been looking for a CAS enabler applet for a couple of weeks now because i don't want to have to by a new calculator (ie hp49g). so is there anyware i can get this applet from?


From my point of view, you ask for something illegal. If I sell you a gun that has a security mechanism ("Stolpersteine") to use only blank cartridges to make some noise and you remove that security measures and aim on people with real ammunition -- I would not like you to do so.

Well, Jordi's aplet is postcard-ware, I don't need it as I have an HP40G (which is not an advantageous tool in my hands, too often I had to do a reset, but it was great fun to do the back-up on my HP200LX). What I want to say: why don't you use an emulated HP40G and test if you _realy_ need that CAS. (Maybe CAS was the wrong tool in my hands anyway <G>)



"From my point of view, you ask for something illegal."

How is it possibly illegal? He owns the hardware.

Ethically it may be a different story. The problem is students could use it to cheat in exams. This could have hurt sales in the past - even though if HP was stupid enough to include a CAS that could be easily activated, it's their own dumb fault.

The 39g isn't sold anymore. I hope one day this aplet is released.

"If I sell you a gun that has a security mechanism ("Stolpersteine") to use only blank cartridges to make some noise and you remove that security measures and aim on people with real ammunition -- I would not like you to do so."

This is a bad analogy, because this kind of menacing with firearms is illegal. What if you sold him a special computer, and he figured out that by flipping a switch, he could double the speed? Would that be illegal?




Hello "."!

You are right, it is a bad analogy. But there is a little bit of truth in it: if Adam might use CAS in the exam he uses his knowledge against the other students, so the HP39 is the "boum" and the HP40 is the "PANG!" The aim is to learn to cheat w/o to be caught.


BTW: With your logic I might be senteced for adultery or gang bang, at least I own the hardware for it <VBG>


I can't beleive this subject about CAS is so damn sensitive. I just thought finding this aplet would be just like finding any other hp aplet. I understand that for students studying for there University Entrance Examinations it should be banned. But CAS is alloud in engineering exams in fact it's advised that you should have a calculator with CAS on it. It becomes a realy good tool when your doing thermodynamics, beams stress calculations etc. For someone like me who is allways short on money and cant exactly afford a new calculator this CAS aplet would be great thats why I ask any of you out there to please send me a copy.


p.s. email is adam.francki@gmail.com


Hi Adam!

It's only my bad analogy that makes the CAS-enabler look like an issue. On the other side I suppose you found following hint at http://members.iinet.net.au/~ccroft/faqs_70-79.htm#79

Anyway: I do not have more knowledge about the aplet that this: http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/forum.cgi?read=63737



It is an applet that is not mine to give. It is post card ware and you should send a postcard to Jordi with your Email address and then, magically, one day, you will see a nice attached file in your email. If he still does this. As to why he doesn't just post it somewhere, is because Hp approached him with the horror story of folding up shop if CAS was ever discovered to be available to the Hp39G. He is probably honor bound by his agreement.

About his method of distribution, well it is HIS software and his pricing stratagy (???). His price is as cheap as anyone could ask. Now your asking us to undercut him???

Just send the postcard and your email address.


To say that one used to be able to get a copy of my aplet by sending me a postcard is an overstatement, Ron. Let me explain. Yes, all the people who sent me a postcard initially (about a dozen) got the aplet, but that's because they were either fellow members of the club (even though they don't really need it), regular posters or well-known enthusiasts, and I made them promise a couple of things, as you can tell.



What did they have to promise? 10 pushup, abstain from using 4-letter-words, and never smoke in public? <VBG>



Just an additional word about "sensitive subjects": Last year in Allschwil (a suburb of Basle) at the "Emulator programmers Meeting" (alas not all could join) it was a topic of a long discussion, where is the limit to something illegal? IMHO, it's not only question of felony and jurisdiction, an other aspect is the respect for the work of art programming the 12k OS of an HP-41 for instance. Today HP itself offers emulators for educators and I am sure this decision will pay off.


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