Data retention - lifetime prediction of modern calculators

[sasa]

Data retention issue is mentioned several times at this forum as side note (at least what I found), however this issue deserve separated thread.

While very old calculators may still works fine after 45+ years, nowadays calculators (including any electronic today) may have a very short life. According to the most problematic lifetime component (capacitors), the lifetime of general electronic are usually the same as a warranty not exceed 3 or 5 years.

Aside of that, the datasheet of nowadays MCUs used flash memory typically state retention times of 20 years at 85 °C and 100 years at 25 °C (in this case former ATMEL MCUs, in specific controlled environment). SRAM have much shorter lifetime (up to 5 years, IIRC). And as well humidity may influence moderately. Of course, these figures are given for ideal conditions tested - I hope there is many EE here which may elaborate with more precise information.

What then we can expect for the real lifetime of quite expensive modern CAS capable graphic calculators? At least I briefly noted, HP Prime, HP-50g and similar (ARM based) have basic warranty of only 1 year.

It would be interesting to hear about experience of modern HP calculator users: duration and frequency of usage, probably defect due warranty period and similar.

[Maximilian Hohmann]

Hello!

(07-12-2018 08:57 AM)sasa Wrote:  While very old calculators may still works fine after 45+ years, nowadays calculators (including any electronic today) may have a very short life. According to the most problematic lifetime component (capacitors), the lifetime of general electronic are usually the same as a warranty not exceed 3 or 5 years.

This is absolutely not my personal experience. Especially older electronic devices used large electrolytic capacitors which have a tendency to dry out and fail while newer devices rather use small tantalum capacitors which have an almost infinite lifespan. In my collection of calculators (1000+ strong) there are very few post 1990 unit which do not work. All my mobile phones, the first one dating back to ca. 1994, still work - apart from weak batteries. All my notebook computers still work, the oldest one being from 1990. My iPad which is now 6 1/2 years old and sees daily use still works without a fault. My car just turned 19 and is full of electronics (digital engine control, antiskid braking, CD radio), and despite not spending a single night under a roof still works flawlessly. The same for cameras - still and video - and TV and audio devices (the only thing in my late 1980ies dolby surround amplifier that has failed is the motorised volume control which means that I have to get up from the couch if I need to adjust the TV sound - something that keeps me young and fit which is why I never tried to repair it ;-) )

So no, I would not fear about the life span of present day electronic devices. It is just the industry which keeps telling us that only the very latest gadget is good enough and needs to be bought instantly and everything older than a year can only be used as landfill.

[Don Shepherd]

I agree with Max.

I have two HP-65's from around 1974, 44 years old, and both still work, the only problem (in the past) being the gummy wheel in the card reader which is a well-known flaw. I have an original Pulsar digital watch from 1973 that still works fine. All things considered, items that were well-made tend to last as long as the owner takes care of them.

I have a PC I no longer use that still works after about 15 years. I had to replace the power supply once.

I have two tablet computers that still work after five or six years. The batteries in my Chromebook failed after less than a year; they were replaced under warranty. I do not like the fact that these batteries are not user-changeable; I would have to take them to an electronics store to replace them now and I'm sure it would not be cheap.

[Gamo]

The only one thing I worry the most about post modern calculator is the LCD screen.
To me this is the most fragile part of all calculator using the LCD.
My HP OmniGo 100 the screen start to get some light black spot in the center of the display.

Gamo

[Leviset]

I have an almost vintage 1970s Citizen Quartz Chronograph still chugging along.
It's so old (Serial Number 91003821) and also says (4-098111K on back case) ) that when setting the date the year only goes up to 2009! You have to find a year below (<2009) which for 2018 is 2007 to match days/numbers of the week/month. It's lost its winder but the stem is still there to move and change the analogue hands.

I also have 2 1960s Bulova Accutrons in perfect running condition
Dennis

[Thomas Okken]

I think the last time I got rid of a piece of electronics because it was starting to fail was in 1984, when I gave away my 1969 Blaupunkt color TV.

Oh, wait, and CD players. My first CD player was a Philips CD-100, which lasted 13 years before it started to go flaky and I gave it away to a Philips fan. None of the CD players I've owned since them have lasted anywhere near as long, except for the ones in my cars. Fortunately the issue is moot nowadays because I don't play CDs any more; after buying them, I rip them, and then listen to them on my phone...

When it comes to calculators and computers, I haven't had anything break on me except three Commodore 64s. (Love the 64, but the hardware was fragile and could be killed really easily by static discharge, and living in a house with wall-to-wall carpeting and central heating, static buildup is a fact of life.) Everything else lasted until I replaced it with something nicer, I think the record is shared by a PC (DIY model) and two laptops (Fujitsu and Lenovo), each of which I used for over a decade until deciding I needed something faster.

[Albert Chan]

My 20+ years old Dell OptiPlex refuse to die.

I only paid $200 for it, with a nice 19" CRT monitor for free.
It was a company close-out sale, which means not cheapy "home" computer.

The monitor alone cost more than $200 at the time.

The keyboard(s), however, does not last long.
I think my coffee spills probably kill them ...

My laptop keyboard also died. This time, for no reason at all, is totally dead.
I just pulled out the laptop keyboard connector, and use a USB keyboard instead.

By the time the laptop itself die, I can re-use USB keyboard somewhere else.

Instead of predicting when stuff died, it is probably best to enjoy it while alive.

[ijabbott]

I've only had two calculators die on me so far. One was a Sharp EL-506R, which I don't really care about. The other was a Casio FX-502P which I threw out during a house move a few years ago as it had become faulty after 25 years or so. I wish I'd kept it now, as it was probably repairable, and I'd had it since 1979.

[Steve Simpkin]

(07-12-2018 08:57 AM)sasa Wrote:  While very old calculators may still works fine after 45+ years, nowadays calculators (including any electronic today) may have a very short life. According to the most problematic lifetime component (capacitors), the lifetime of general electronic are usually the same as a warranty not exceed 3 or 5 years.

Aside of that, the datasheet of nowadays MCUs used flash memory typically state retention times of 20 years at 85 °C and 100 years at 25 °C (in this case former ATMEL MCUs, in specific controlled environment). SRAM have much shorter lifetime (up to 5 years, IIRC). And as well humidity may influence moderately. Of course, these figures are given for ideal conditions tested - I hope there is many EE here which may elaborate with more precise information.

Modern surface mount electrolytic capacitors usually only have a short lifespan only if they are constantly exposed to high temperatures. At normal room temperatures, they will typically last for decades (assuming they are not of poor quality or defective).

The same is true of Flash memory. If not constantly exposed to high temperatures, they will retain their data for decades.

I have never heard of endurance issues with SRAM.

One potential item to be concerned with is the use of lead-free solder in modern (since 2006) electronics. There have been reported cases where "whiskers" have formed between soldered component leads that have resulted in device failures. I believe the potential for this problem has been largely mitigated through the use of additives to the tin used in the component soldering process.
More information on this subject:
https://www.maximintegrated.com/en/app-n...vp/id/5250
https://nepp.nasa.gov/WHISKER/background/

[pier4r]

(07-12-2018 03:22 PM)Gamo Wrote:  The only one thing I worry the most about post modern calculator is the LCD screen.
To me this is the most fragile part of all calculator using the LCD.
My HP OmniGo 100 the screen start to get some light black spot in the center of the display.

Gamo

It is impressive how I wouldn't ever doubted a LCD screen, but this forum taught me otherwise. Although I presume that used LCD will somehow last longer.

[Garth Wilson]

I have a lot of LCDs from the late 1980's and 90's and they all work like new (even if their bezels are kind of corroded and no longer shiny). LCDs' greatest enemies seem to be UV, and heat and moisture, especially the combination of these two. Impacts might be in the list too. It is my impression that if these are avoided, and LCD should last indefinitely.

[factor]

I have a Casio Data-Cal DC850 for more than 10 years, or 20 maybe. Even it is a credit card size calculator it supports dual coin battery for data retention. The quality is so good it is still working perfectly today. Every key is functioning, and the LCD screen is perfect.

I'd say the engineers of this product did an excellent job for both design and manufacturing quality.

https://gmgolem.wordpress.com/tag/dc-850/