Module getting erased?

Programs for HP-41

Module getting erased?

Postby jimwsong » Sat Apr 11, 2020 12:14 am

I have had my HP 41CX for over 30 years. I have not used it for 25 years since I graduated from engineering. I have multiple application pacs I would like to use. One specifically is real estate pac for finance and TVM calculations. I go to execute by pressing XEQ $ (A) key, and it says nonexistent. Is it possible for these modules to get erased over time? Or become demagnetized? I thought they were hard coded into the chips.

Or

Maybe I am not doing something right to initialize the pacs to enable the overlay?

Appreciate any words of advice.

Thank you, Jim
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Re: Module getting erased?

Postby Garth » Sat Apr 11, 2020 12:44 am

I believe all the ones produced by HP are mask-programmed, so there is no way they can be erased, even by age. There might have been EPROM modules programmed by third parties, and EPROMs are generally only guaranteed to hold their data for ten years; but I have never seen an EPROM lose its data even in 30 years, unless light was allowed to reach the UV window (if it even had one). In any case, none of the memory types (except for the old core memories) are bothered by magnetic fields of any strength. Even modern ferroelectric RAM is ferroelectric, not ferromagnetic. And for magnetic media, I have tapes for the intelligent HPIL microcassette drive that all read perfectly, time after time, file after file, even now 30+ years after they were recorded. I also have 60-year-old tapes of Frank Sinatra singing that still sound outstanding.

I don't have the real estate or finance pacs, but I can imagine the TVM program would have to be started similar to how it is started in the Advantage module. If the program counter is not in a program that has a label 'A' for example, you'll get the "NONEXISTENT" message. For the TVM program in the Advantage module, you first XEQ 'TVM' to get into the program so you can get the options like you're talking about.
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Re: Module getting erased?

Postby rprosperi » Sat Apr 11, 2020 2:23 pm

Does the Real Estate module appear when you do a CAT-2 ?

After years of non-use, the contacts (both in he module and the 41's ports) are often oxidized and/or dirty and they don't make contact when the module is inserted. If CAT-2 does not confirm the module is seen by the OS, you can do these things, carefully and gently, to try to ensure the module can be read:

A. Clean the contacts inside the 41's ports using alcohol on a q-tip.
B. Clean the 'finger' contacts in the opening of the module with thin q-tips and alcohol or contact cleaner. If they are heavily dirty or oxidized, an emery board (typically for ladies nails) or folded fine sand paper can be used to clean the raised bump portions of the fingers that make contact inside the 1 ports. If you do use these, be sure to clean any residue before inserting the modules. [BE SURE TO NOT BEND THE FINGERS WHEN CLEANING THEM]

Good luck
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Re: Module getting erased?

Postby jimwsong » Sun Apr 12, 2020 3:21 am

Thank you. I do see the program running. But when I input value and press R/S and go to the next value, it sometimes gives me an error message. I been following the key strokes of the book, exactly. So I will now try to clean the leads with a qtip as prescribed and see if this will allow the program to run consistently.

I am so used to the 41CX keys, even using 12C, which can do things like CFo and CFj, Nj for non conforming payment, I rather use the 41CX if I can fingure out how to get it to run these programs. I think ti may be user issue (me). Because this is flawless HP 41CX. I stored with without battery for close to 30 years. Now I am starting to collect he various pacs from Ebay to use it more frequently.

Also, the manuals on the site is nice, I am going to see if I can turn all fo those independent jpg files to a single PDF file. It was painful down loading each JPG. But better than paper for sure.

Thank you for this awesome forum, who ever is running it.
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Re: Module getting erased?

Postby Garth » Sun Apr 12, 2020 4:28 am

If the program in the module runs at all, I have to think that eliminates the connector as a source of trouble. If there were a problem there, it wouldn't work at all. So I think you should leave the connector alone and not risk damaging it, particularly with anything abrasive. If there's any doubt, you could try plugging the module into a different port; and if there's any problem with the calculator port, this should expose that. That does remind me of another thing that sometimes needs attention to though, which is that some combinations of modules don't want to be plugged in one above the other. I don't know the rules for that though.
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Re: Module getting erased?

Postby rprosperi » Sun Apr 12, 2020 1:20 pm

I totally agree with Garth; if CAT-2 works and the program runs at all, the contacts are very likely OK and I would not mess with them, they are quite delicate.

Are all of the programs noted in the manual listed when you do A CAT-2? If so, then it's possible the problem is the manual's instructions are unclear or incomplete (though that seems unlikely); I've never heard of a module that can be accessed and runs, but not correctly.

As for the manuals, you can only access them page-by-page when accessing from the website, however Warren now allows you to download the entire collection of complete PDF files (and .mod files, etc.) via bit-torrent, the details can be found here:

http://www.hp41.org/Archive.cfm

It is well worth the time to learn to use bit torrent (if this is new) as it's easy to do (though not fast) and having the complete manuals will be very helpful as you expand your exploration of your 41CX.
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Re: Module getting erased?

Postby jimwsong » Wed Apr 15, 2020 3:29 am

Bit torrent won't run on my latest MAC OS. I wonder if there is an updated version?
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Re: Module getting erased?

Postby jimwsong » Wed Apr 15, 2020 3:33 am

All modules show up when I do Cat 2. I found out it is a bit finicky. When I first do Xeq alpha Gold key P ($) alpha, it runs. Then after, I can just do Xeq $ and it runs. $ key is assigned on real estate pac on the first top left key.

But when I execute certain programs and follow the instructions in the manual and R/S to next step, it then gives me some message vs. executing it forward. I am going to try taking out all modules and only use the module with X-Memory pacs (2) and see i that gets rid of these issues. It could be multiple modules may be conflicting. Not sure.
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Re: Module getting erased?

Postby jimwsong » Wed Apr 15, 2020 8:49 pm

Is there a optimal configuration to put in the modules?

Such as X-Memory modules in 1 and 2 slot, and the module i plan to use in 3rd or 4th slow? I use the other slot for IR module. I figure, I can use that module to fill up a space, or maybe leave one of them empty? The module I want to use the most are finance 1 and security modules.

Also, to Garth. Does the HP advantage module come with a template? I do not remember ever getting one when I bought that module.

Thank you
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Re: Module getting erased?

Postby Garth » Thu Apr 16, 2020 12:20 am

The Advantage module did not come with a keyboard overlay.

As for the rules about how the modules are arranged, I don't know. Most combinations will work, but there are a few things to watch out for. I still don't know the rules. I have my 41cx full though, except for a single 4KB block. Here's a CAT 2 listing, using the HP92198 80-column video interface (on HPIL) and a monochrome monitor. I did not have the bar-code wand or card reader plugged in when I took this:

CAT2_12-12-17.jpg
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