Would the HP-15C Limited Edition Firmware Age Away?

[Dan Grelinger]

In a conversation that I am having with an Asian HP collector, he said he put an HP-15C Limited Edition away with batteries removed for 5 years and recently took it out to test it. After an initial "Pr Error", the calculator would not operate. He called HP and they said they do indeed recommend storing the calculator without batteries, and secondly, that after a long period of time, the firmware would fail and the calculator would not longer be usable and could not be repaired. I don't know if the two statements are related.

I assume that the HP-15C Firmware is in flash memory. From what I know about flash, it does have a limited storage life (10 years, 50 years?), but that this period is not influenced by power being applied or not.

Is there any danger of an accelerated firmware loss if the calculator is stored for an extended period of time without batteries installed?

[Gene]

Really should not be a problem to store this without the batteries for 5-10-15 years.

Your friend may have been speaking with a less than informed Support Person. That does happen.

I suspect it is simply bad luck of the draw on his unit rather than a real issue here.

[BartDB]

The problem described is typical of low batteries. Did he try new batteries or the ones that originally came with the calculator (which may be low due to 5 years of self-discharge)? Suggest to him to try good batteries from a decent brand purchased at a reputable store.

[teenix]

(03-13-2018 09:08 PM)Dan Grelinger Wrote:  In a conversation that I am having with an Asian HP collector, he said he put an HP-15C Limited Edition away with batteries removed for 5 years and recently took it out to test it. After an initial "Pr Error", the calculator would not operate.

I think the fact that "Pr Error" appeared proved the hardware worked. Maybe faulty batteries, dirty battery terminals?

cheers

Tony

[rprosperi]

I think Tony hit the nail right on the head. Ironically, seeing "PR ERROR" is a sign that the machine (and f/w) actually are intact, and it's likely a simpler issue as noted. How weird is that, that an "error message" confirms the unit is good... lol ?

[Dan Grelinger]

Yeah, I thought about the low batteries possibility and suggested he try new batteries. Thanks for the suggestion/confirmation.

Dan

[jjohnson873]

(03-13-2018 09:08 PM)Dan Grelinger Wrote:  I assume that the HP-15C Firmware is in flash memory. From what I know about flash, it does have a limited storage life (10 years, 50 years?), but that this period is not influenced by power being applied or not.

Is there any danger of an accelerated firmware loss if the calculator is stored for an extended period of time without batteries installed?

Flash memory storage for most embedded microcontrollers is designed for +100 years before the charge on the memory cell will leak enough to flip a bit. It can be accelerated by high temperature, well above normal room temperatures. Normal operating voltages should not affect the flash memory cells. Of course if they took the calculator into outer space, a random alpha particle could have caused a single event upset and flipped a bit in the flash memory. ;-)

[teenix]

(03-14-2018 03:17 AM)jjohnson873 Wrote:  Of course if they took the calculator into outer space, a random alpha particle could have caused a single event upset and flipped a bit in the flash memory. ;-)

There must be a lot of those floating around my PC when I'm coding ;-)

cheers

Tony

[cyrille de brébisson]

Hello,

First, the support person is definitely at fault here. Disseminating bad information.
Second, I woudl agree that the battery should be verified and that the PrError is a sign that things are actually pretty good.
Thrid, I have have not looked at the CPU doc, but I am prety sure that the ATMEL chip has a flash life which is longer than 5 to 10 years. These chips are designed to last decades, not years.

Cyrille

[Dan Grelinger]

Thanks for all the help. I have passed it along and if I hear the result of trying new batteries, I will let you all know 'the rest of the story'.

[TheKaneB]

My 15C (the original model) would randomly crash and lockup while using dead batteries. I'm not sure about the 15C LE though, since it is a very different machine. If the system gives you a Pr Error most definitely the chip is working but something could be off. I wouldn't dismiss a corrupted memory with 100% certainty. I'm not talking about flash cells discharging themselves but electrostatic discharge could in theory fry those chips (I know, they have ESD protection most of the time, but you never know).

Anyway, let us know how it goes.

(03-14-2018 05:29 AM)teenix Wrote:  

(03-14-2018 03:17 AM)jjohnson873 Wrote:  Of course if they took the calculator into outer space, a random alpha particle could have caused a single event upset and flipped a bit in the flash memory. ;-)

There must be a lot of those floating around my PC when I'm coding ;-)

cheers

Tony

You must have a lot of "alpha" software there

(bad pun, I know, shame on me)

[Dan Grelinger]

It turns out my Asian acquaintance has two HP-15C LEs that he has squirrelled away, and they both stopped working. However, he was able to get one of them working by switching batteries around. The same set of batteries won't get the other calc working. I have asked him to confirm that he is using a brand new set of batteries, as I suspect that the batteries that work in one calculator are marginal and won't work in the other.

[Greg]

One of the more interesting errors I saw come out of the HP firmware was for a HP-29C.

It wasn't a real calculator, just an emulator, but the first time I tested it; it said "Error". Not surprising for a new bit of software but actually getting that far meant that a lot was actually working. Now in a twist that might be more relevant to this thread, the actual problem it was complaining about was the "continuous memory" was empty.

It had never been switched on before and all of the RAM contained zeroes. That caused the "Error" display. If a 15C has been sitting without batteries for 5 years, there's a good chance that the CMOS has zeroed itself. In that case, applying batteries and doing a switch off / switch on should initialize the memory and all will be well. I don't know if this applies to the 15C - it was really after my time. With the emulator, I only saw the "Error" once. After that the simulated CMOS always came up fine.

This may be of some use - or a total red herring. Hopefully the former.

[rprosperi]

(03-18-2018 04:53 AM)Greg Wrote:  One of the more interesting errors I saw come out of the HP firmware was for a HP-29C. It wasn't a real calculator, just an emulator...

Where did you see an HP-29C Emulator? That would be of interest to a lot of folks here.

On the 15C, such a condition at power-on produces a display of "PR ERROR" which is exactly what the OP reported was seen, so yes, simply dead batteries seems to be the case here as well.

[SlideRule]

(03-18-2018 01:09 PM)rprosperi Wrote:  … Where did you see an HP-29C Emulator? That would be of interest to a lot of folks here…

Rob - PM sent.

BEST!
SlideRule

[rprosperi]

(03-18-2018 02:33 PM)Mike (Stgt) Wrote:  You find one from Bernhard, and another one from Tony (updated today). If there are more around in public please tell me publicly.

Ciao.....Mike

Mike, I should have mentioned those 2, clearly well-known to folks here. I presumed the OP was referring to some other not well-known emulator, though it seems unlikely, in the same hope as you, to find out more about it. I fear it's either one of these 2, or in fact a simulator.

[SlideRule]

(03-18-2018 02:47 PM)rprosperi Wrote:  … referring to some other not well-known emulator, though it seems unlikely, in the same hope as you, to find out more about it. I fear it's either one of these 2, or in fact a simulator …

Rob, my prior post refers to one which toggles between a 29c & a 19c, however, I seem to no longer have any accompanying documentation.

BEST!
SlideRule

[Greg]

The HP-29C emulator was one of my collection, the hp29u

Bernard's and Tony's are also excellent but the goal for mine was to run on anything.

[rprosperi]

(03-18-2018 08:11 PM)Greg Wrote:  The HP-29C emulator was one of my collection, the hp29u

Thanks Greg, will definitely check it out. Nice feature to provide a local use (disconnected) option. Wish more online html-based apps did this.

Update: The "Install it" option is not working, I get (in NY) a 404 error.

[Greg]

Sorry Bob. It's not a NY thing. It is an error on the page. I've fixed the page.

If caches give you the earlier version it now says:
http://www.sydneysmith.com/products/hp29u/run/app.html