Hah, what a coincidence this post is.
Just last week I had to open first time alarm clock with green 7-segment display. Because I accidentally dropped it while vacuuming and antenna cord broke as it was so firmly under picture frame holding nail. And while open cleaned interior from dust, used greasy PRF to lubricate pots, switches and tuning wheel. If I recall correctly it did have that LM8560 chip in int and with display looked almost exactly what was in subject article inside.
Label on bottom claims: -----------------------------
Luxor CR 9016
NOKIA Consumer Electronics
International S.A
(FI)(N)(S)[x] 230V ~ 50Hz
Battery 9 V
MADE FOR NOKIA IN CHINA
-----------------------------
SERIAL NO.
9302-00106
Q: But why the device is branded Luxor and it's made for NOKIA? A: Because NOKIA bought bit earlier that year (1985) Swedish Luxor consumer electronics. And I guess they did not had yet time redo chassis with NOKIA printed on and this was a still products transition period.
NOKIA was still at that time making also TV sets and was about to bring two years later its first completely new way of implementing analog TV using digital processing chips, which allowed quite nice fieatures like PIP which was great help making VHS recording without ads. I had one of those TV-sets (M-model) and used it about 10 years.
But that alarmclock radio from -85 is still going strong, good shape and it definitely was good purchase about 40 years ago.
e: Sorry about formatting, I tried to find how to format literally, but couldn't find. OK, good enough now.
Great passion for the subject, definitely doesn't get discouraged by their less than perfect command of English and didn't use an LLM to butcher the text's authentic character.
I find that in my own writing I no longer strive for perfect grammar and polish since nowadays it actually cheapens the end result, everybody has perfect grammar today.
This summer I've made indoor (no direct sunlight) solar powered kitchen timer and I used STM32L011, it's winter and it's still working and voltage is stable. The power consumption is 100-150uA (28uA for display, 80uA for mcu, the rest is 1.2-to-3V boost). But it's only on when I cook (maybe 1h a day).
> Moving from Italy to Germany, I noticed that my clock radio with the LM8560 is considerably more accurate in Germany than Italy. Here, I never need to adjust it.
The interesting thing is that both countries are part of the Continental Europe Synchronous Area, so they are by definition running on the same frequency.
There must be a different explanation for the change in accuracy, but I wonder what?
I was excited to see the features of the chip that most clock manufacturers left undocumented described. There were a few I wasn't aware of and I'm going to try them on a vintage clock. I remember doing the hour/minute while holding alarm to reset the alarm to 0:00. I found that when I was a kid and thought it was so cool to discover a feature.
The article bringing up flip-flop clocks reminded me of another mechanical digital clock that I can not quite remember the name of. It was from roughly the same time period as the flip-flop alarm/radio clocks but the numbers were wire grids or cutouts in wire grids and as the numbers changed they sort of faded from one digit to the next. I can't quite remember how the mechanism worked and the only clock of this sort I have ever seen was the one I bought ~20 years ago just to take apart and see how it worked. Anyone know what I am talking about?
The mechanism was surprisingly simple once I got it opened and saw how it worked but from the outside made no sense, I probably stared at that clock for an hour trying to figure out how it worked before I finally opened it up to see what was inside. I might still have the clock mechanism in a box out in the garage.
Edit: I suspect these clocks were actually from the time period at the end of flip-flops, showed up too late to become common, LEDs/LCDs killed them. The digits were on the dim side, perfectly fine for a bedside alarm clock and quite good for that situation but you had to be fairly close to clock to read it in a well lit room. Better than a flip-flop in a dark room but worse than an LCD in the light.
A retro red LED clock actually adds to the calm atmosphere of my bedroom. I can’t really sleep without one now.
On the other hand, the only saving grace about my bright green and blue LED router is that someone whose hand should be shaken thought to allow software disabling or even a scheduled disabling of the LEDs.
One of the most interesting aspects it that it's all state machines and logic, with no CPU. This explains the weird glitches, e.g. having to not release one button while pressing another to avoid erroneous time setting. It shows what we take for granted that's trivial to do in software.
In high school I had one of the mechanical "flip" clocks. Then later an LED clock which almost certainly used the LM8560 (a Sony, which lasted far longer than I expected. Back when products were built with quality in mind). And as the article says, the chip depends on the AC frequency (50/60 Hz) to keep accurate time. For the US market, that input was likely hardwired to 60 Hz via a jumper. Japan must have used a switch, given it's mixed 50/60 Hz national power standard.
These days I have an LCD clock that does not use the LM8560 but instead gets it's time from the Radio Data System values embedded in the FM broadcast. Possibly using the Sanyo LC72723 to decode them. The CT (clock Time & Date) data field is accurate to within 100ms according to wikipedia:
On that note. I tried to make candle replacement out of yellow LEDs in the 1980-years. To read books in de tent. But no matter how many leds I added it just was not enough.
> “Digital” doesn’t mean necessarily “electronic”. It means that the time is show actively by digits and not by hands.
Kind of weird since digitus means finger.
I remember how badly these radios would drift off-time when running on the battery backup! He explains in the article about how the back-up oscillator is a simple R-C circuit because the power line reference is absent.
It would also kill the backup battery in a couple of hours. If you're in an area with prolonged, frequent backups it wasn't worth installing the battery. It was only good for occasional, short blackouts of a few seconds or less.
Then in the late 90's and early 00's you almost got alarm clock at "Dollar Stores" for $15, and for really cheap pocket FM radios, you could get them as prizes with sodas and such, as a marketing scheme, with the soda logo printed in the device.
With no internet, often you were in $REMOTE_FORGOTTEN_RURAL_VILLAGE and the TV antenna didn't have tons of nearly TV repeaters/relays, you would love some FM/AM radio with cool stations reaching over 100 and 200 kms in case of AM ( I remember to listen heavy metal/gothic metal stations from Portugal in Spain within 100 kms from the border ). In Spain, either boring national and international pop radioformula, or soccer past dinner everywhere.
Oh, btw, one thing I hated from these clocks it's having to reset the time because it was misconfigured on a power cut. Nowadays they could just put some firmware and flash it for 0.0001 euros per device, if not less.
Being not a programmed micro controller, the LM8560 is also a virtually eternal component. Many modern micro controllers incorporate a flash memory to store the software that let the controller work and execute the desired functions. Flash memories retain their content not for an unlimited lifespan. It may be several decades, but before or later it comes the day when they begin to lose their content, and the micro controller stops to work. This can’t happen to LM8560, because it doesn’t contain any flash memory.
As an electronics experimenter I would have to say the REAL eternal chip is the 555 introduced in 1972. It's become a bit of a meme: You could have used a 555 for that!
https://en.wikipedia.org/wiki/555_timer_IC