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Calculator blog


Musings and comments about our common interest

 

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HP41CL back in!

 

IMG_0235While performing website maintenance tasks, I discovered that I had the HP41CL as “not available” and therefore it could not be ordered. I have fixed it and now it can be purchased again.

Be aware that we can also perform conversions. That is, if you have a HP41C that has been with you a long time, is in working condition and has square screen corners, you may consider taking it to surgery. This surgery is not cosmetic at all - oftentimes you won’t be able to distinguish one from another, unless you have ordered it with serial cable. We perform that modification for 450 €, or 486 if you want the serial cable and connector fitted too.

We have also a gorgeous unit with original box and manuals. It is more expensive - but you cannot have better.

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More units of HP41CL

 

3 new units of HP41cl

 

We have three decent hp41c calculators and 3 hp41CL circuit ready for assembly. I know that some of you were waiting for the new batch of circuits to arrive - so, you can already order them.

 

These differ from the previous models just in the additional modules Monte has entered since. Let’s be honest - all the important ones were in long ago - the new ones being included are at the very end of the rarities camp.

 

While the HP-produced modules were the most useful models at the beginning, there have been some user-produced modules that I feel are even better. Let’s agree that probably the best module from HP was the Advantage module, which effectively made a new calculator of the HP41c - with all the features that then were missing from the HP 15c.

 

For programmers, though, the most useful one has to be the CCC module. However, this is very heavy in programming and less useful for general users.

 

In my opinion, Angel Martín’s Sandmath modules are the best companions you may have if you have any scientific work to do (among the Sandmath modules, the better the latter). In my HP41CL, I have “plugged” the Advantage module and the Sandmath module. I don’t feel I need more for what I do. And with that power at hand, I don’t need any of the next calculator models.

 

Another issue is when you teach your children. There, a Prime can come handy.

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HP 41CL Appreciation

I take always in my travel bag both an HP41CL and a HP Prime. But when it comes to do calculations at work, it is always the HP41CL that I reach for.

On one side, the legibility of the screen is better in our office - there is higher comfort in reading the 34 year old segment screen than the new LCD computer screen.

Second, most calculations are simple enough to be done without resorting to complex functions. It would be totally different if my job involved lot of vector or matrix use - data management is  couple of orders of magnitude better with the Prime (as it is the case if it was statistics - data fill in is so much better with it)

Third: programming the HP41CL for simple tasks is so much easy and bug free (at least with my current knowledge level). Once you have finished the program, you can assign it to a key. It can be done too with the Prime - it is just a little bit more cumbersome.

Fourth - it is very easy to set up an alarm with the HP41CL - easier even than setting up your iPhone for the task, as I have the XYZALM function assigned to a key.

The power of the resident calculator there (a Prime prototype, with the white back - these will be collector items in EBay in the future) does not make me forget how easy most tasks are with the 41CL (loaded with the Advantage and Sandmath packs). I guess that I will need to devote much more time to learn the Prime in order to get an even playing field. 

It now takes me minutes to make any useful program by using the HP41CL and the additional functions contained in both the Advantage and Sandmath packs. My mind is wired in RPN - which is not necessarily an advantage in these days. It takes me much longer to make a very simple program in Prime; and somehow I manage always to introduce a nasty bug in my first attempt, while most programs in HP41CL RPN work well, first time.

If you always wanted a HP41c and you could not at the time (it was my case), and now you can but you think it’s not worth it anymore, think twice! With a 41CL, you don’t need to buy additional modules and you have an incredibly function-rich calculator, which is still expandable. I bet it is difficult to find a significant scientific application for which there are not programs already recorded in all the modules the HP41CL comes with. 

You can find quite cheap HP3468A/B multimetres, that allow you to record measures at will (and, if you have the time module, program readings in specific time periods). You can print the results with either the infrared printer and a new HP 82240B printer, or an old HP IL printer, and then store them in the enormous memory of the 41CL. And it is still supremely portable. 

In the future, when these are not available anymore, you will hate yourself for not having the calculator of your youth in the best possible format! Order now when it is still available!

 


 

 

 

 

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The HP 41CL is back!

The HP-41CL is back!

There is a new batch of 41cl boards. I have ordered enough to liquidate my stock of hp 41c bodies.

There is even one boxed, with original manuals. It will command a higher price, though. Not decided yet.

For my personal use, I prepared a tall keys, early serial number hp41c, with time module. As I am now commuting between countries, it’s not the best equipment to travel with. That attribute is for the hp 15c LE, that gets in my jacket pocket. So the 41cl stays in Spain. I really miss the sweet keyboard when I'm abroad. The power of the resident calculator there (a Prime prototype, with the white back - these will be collector items in EBay in the future) does not make me forget how easy most tasks are with the 41CL (loaded with the advantage and Sandmath packs)

The boards will arrive early next week - finally.

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A hint for the HP 41CL

If your HP41CL seems to lose the configuration after a low battery sign, or a change of batteries, and you are fearing to go through the whole installation procedure, do not fear! You don't need to do that. If you have assigned some keys using functions from a plugged in port, and you see XROM xx, do not worry: the memory loss has not been so big or so long as to lose the keys assignments, and therefore most likely the whole setting can be reinstated.

You just need to reenable the memory management: XEQ MMUEN. This will make the calculator again aware of the whole memory area. You can now use re-assigned keys and see that they keep the right function name on it.

This method does not work when you receive the dreaded "MEMORY LOST" message (below that of the HP41CL when it was born!)

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Repairing the rusting battery bay of HP41c.

You may have bought an HP-41 in EBay, just to find that the battery bay is utterly rusted. There goes your investment! Maybe you wanted it for CL conversion - maybe it was your first 41c and you wanted to see what’s all the fuss about it!


Whatever the reason, letting the rust inside your calculator is a recipe for later disaster. It will corrode the circuit lines, communicate to other parts of the circuit, destroying your investment (and, in the case of the CL, it IS an investment!)


You can easily buy port covers, even battery cover; but it is much more difficult to find this piece in internet. And with a good reason: it is the first thing that fails in the HP41c, and therefore you can only salvage the other parts.


Well, there is an option: you can buy in our shop the adhesive circuit that adapts to the plastic body of the battery connector. It has an extremely strong bonding, and the shape is perfect for the task. I have to say that it is a little difficult to put it properly: you need a firm hand and some experience to do it. I would not recommend to buy one to repair your only calculator, since it will not work properly the first time. At least it did not work for me the first time, but I got the experience of what failed. The second time went well already. So, my advice is: if you want to repair just one calculator, you’ll be better off buying two. If you’re repairing more, then n+1 - so that you can afford one error. Or you may be more skilled than me - in than case buy just as many units as repairs you need to do.


The circuit comes with clear repair instructions, but I would stress the fact that you need to bend it properly to shape beforehand, using the guidelines, and that you should start in the cavity between both ports.


I have used it to repair a calculator that would not start, and that I bought in internet as “for parts”. Now it is my CL. Today I have just repaired a non-working CV - this time keeping the original board in. This will end up in another CL as soon as I receive the new boards, with Sandmath 2x2, among other new features.


Please take a look at the beautiful finish of the battery once repaired.

IOBLOCK_REB_ITN.jpg

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You can find it here.

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HP41CL and time module

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I have found a time module for the HP41CL and I am now enjoying the facilities it provides.

The most important part, in reality, were the time functions that were already available from the beginning, thanks to the architecture devised by Monte; but it is nice to use your calculator as a machine to keep your appointments. Of course, an smartphone is much better for that purpose, even as a chronometer; but together with the HP IL interface, the HP41CL is able to control many things, like lighting, multimetres, even oscilloscopes.

You may have read my messages about the HP3468A. This is an HP-IL enabled machine. I have two units (one for me, one for the shop), that I have converted to 230v/50hz use. They work flawlessly with the HP41CL.

We have an apartment in a mountain area. We know that the voltage there is not too stable, and the drops have damaged in the past some appliances. But, of course, the local utilities company denies everything (although they have started working to improve the supply with a new transformer house nearby). To prove the point, I have set up the voltage meter of the HP3468A so that it is triggered and read by the HP41cl each 5 minutes. This way I am able to map the whole performance daily. It is a pity that this method does not allow me to see the real peaks and valleys, but at least it gives a good proxy to the real situation. Then you can make some statistical calculations, apart from knowing the waveform (since I am also storing all the points - it is a pleasure to have such a big memory). I have seen voltages as low as 193, which is 16% lower than the European standard at 230.

(By the way, do you know the reason for the 230v? I have been told that the European bureaucrats, faced with different voltages across the English channel (240 and 220v), decided to set the standard at 230 and just enlarge the tolerances. That way, the UK would continue at 240 and the rest of Europe at 220, and everyone would be happy - except the appliances, working with much wider voltage tolerances)

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New products in the web

Today I am beginning to put in the website some of the modules I have. Some of them come with manuals, even a couple of them boxed.

Why?

Now that I have the mighty HP 41CL, there is no need for physical ROM modules. The only modules that may be necessary are the ones that have other utility beyond the ROM itself: the infrared printer module, the HP-IL module (of which I have now 2: one for me, and another to be sold with a HP 3468A multimetre to create a “vintage calc lab”) and the time module. These I will keep.

The modules I will be putting in the accessories part of the web are the following:

  • A CCD module, complete with manual and byte combinations sheet.
  • A Math-Stat module, boxed, with overlays
  • A home management module, boxed, with overlays
  • An Advantage Pac, with manual
  • A couple of X-Memory modules.
  • A couple of X-Functions modules

As soon as I modify it to European voltages, I will put in the web an HP 3468A HP-IL multimeter as well. I am keeping another one for me - it is amazing what can be done with that multimetre, a time module and a HP41c.

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I have lost my HP 15c LE !


I have Lost my HP15cL
This week I was traveling on a business trip to Norway. Many nice things - but somehow I managed to lose my trusty HP15c LE. It belonged to the initial American shipment, with serial number 182. The ones I have been selling were in the 23k range already. 
Now, although I carry the HP15c in my jacket pocket all the time, it is with the HP41CL how I perform most of my financial work. But I had the HP15C LE programmed with all kind of financial programs (you can see previous installments of this blog to see a description of these programs. I have developed a version for the HP41CL for those that happen not to be in one of the zillion modules it comes with.)
The good thing is that I kept 5 units more in reserve. My thought was: “one for me, two for each of my two children”. Maybe they will be more attracted to the new HP Prime… In any case, I will have to spend significant time in writing all the programs back into the machine. But it is worth it: in board meetings, we can compare return rates for projects immediately - much shorter than the time it takes to open excel and test some hypothesis. And there is no way you can come into the boardroom with the whole HP41CL shebang, showing yourself a little bit as a luddite. (if only they knew that they are looking at the best current scientific calculator available…)
I have some hints about where I may have lost it. I will try to find out tomorrow, but the chances are slim...
Fortunately I did not lose my original HP15c, which has the exact same programs in. 
On the other hand, I will have the guilty pleasure of opening again a new calculator - even though I did it already in the past.

I have Lost my HP15cL!!

This week I was traveling on a business trip to Norway. Many nice things - but somehow I managed to lose my trusty HP15c LE. It belonged to the initial American shipment, with serial number 182. The ones I have been selling were in the 23k range already. 

Now, although I carry the HP15c in my jacket pocket all the time, it is with the HP41CL how I perform most of my financial work. But I had the HP15C LE programmed with all kind of financial programs (you can see previous installments of this blog to see a description of these programs. I have developed a version for the HP41CL for those that happen not to be in one of the zillion modules it comes with.)

The good thing is that I kept 5 units more in reserve. My thought was: “one for me, two for each of my two children”. Maybe they will be more attracted to the new HP Prime… In any case, I will have to spend significant time in writing all the programs back into the machine. But it is worth it: in board meetings, we can compare return rates for projects immediately - much shorter than the time it takes to open excel and test some hypothesis. And there is no way you can come into the boardroom with the whole HP41CL shebang, showing yourself a little bit as a luddite. (if only they knew that they are looking at the best current scientific calculator available…)

I have some hints about where I may have lost it. I will try to find out tomorrow, but the chances are slim...

Fortunately I did not lose my original HP15c, which has the exact same programs in. 

On the other hand, I will have the guilty pleasure of opening again a new calculator - even though I did it already in the past.

 

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I have lost my HP 15c LE !

I have Lost my HP15cL
This week I was traveling on a business trip to Norway. Many nice things - but somehow I managed to lose my trusty HP15c LE. It belonged to the initial American shipment, with serial number 182. The ones I have been selling were in the 23k range already. 
Now, although I carry the HP15c in my jacket pocket all the time, it is with the HP41CL how I perform most of my financial work. But I had the HP15C LE programmed with all kind of financial programs (you can see previous installments of this blog to see a description of these programs. I have developed a version for the HP41CL for those that happen not to be in one of the zillion modules it comes with.)
The good thing is that I kept 5 units more in reserve. My thought was: “one for me, two for each of my two children”. Maybe they will be more attracted to the new HP Prime… In any case, I will have to spend significant time in writing all the programs back into the machine. But it is worth it: in board meetings, we can compare return rates for projects immediately - much shorter than the time it takes to open excel and test some hypothesis. And there is no way you can come into the boardroom with the whole HP41CL shebang, showing yourself a little bit as a luddite. (if only they knew that they are looking at the best current scientific calculator available…)
I have some hints about where I may have lost it. I will try to find out tomorrow, but the chances are slim...
Fortunately I did not lose my original HP15c, which has the exact same programs in. 
On the other hand, I will have the guilty pleasure of opening again a new calculator - even though I did it already in the past.

I have Lost my HP15cL!!

This week I was traveling on a business trip to Norway. Many nice things - but somehow I managed to lose my trusty HP15c LE. It belonged to the initial American shipment, with serial number 182. The ones I have been selling were in the 23k range already. 

Now, although I carry the HP15c in my jacket pocket all the time, it is with the HP41CL how I perform most of my financial work. But I had the HP15C LE programmed with all kind of financial programs (you can see previous installments of this blog to see a description of these programs. I have developed a version for the HP41CL for those that happen not to be in one of the zillion modules it comes with.)

The good thing is that I kept 5 units more in reserve. My thought was: “one for me, two for each of my two children”. Maybe they will be more attracted to the new HP Prime… In any case, I will have to spend significant time in writing all the programs back into the machine. But it is worth it: in board meetings, we can compare return rates for projects immediately - much shorter than the time it takes to open excel and test some hypothesis. And there is no way you can come into the boardroom with the whole HP41CL shebang, showing yourself a little bit as a luddite. (if only they knew that they are looking at the best current scientific calculator available…)

I have some hints about where I may have lost it. I will try to find out tomorrow, but the chances are slim...

Fortunately I did not lose my original HP15c, which has the exact same programs in. 

On the other hand, I will have the guilty pleasure of opening again a new calculator - even though I did it already in the past.

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