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Casio-F-91W die-shot

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Re: Casio-F-91W die-shot

#121

Post by shirro »

interfixus wrote: post #112
smackeyacky wrote: post #59

Earlier quoted context omitted.

Get a Casio G-Shock. The 800 models can sync with your phone and the time is auto corrected. I bought a GBA-800 from a pawn broker - out of the dozen or so watches in my box it's the one I reach for if I have to know what time it is accurately.

Absolutely, get a G-Shock. But get one which radiosyncs. Most phones (and PCs), although synced by internet, reliably lag between one and two seconds. My synced G-Shock is always correct to within better than one tenth of a second, that is, to the limit of observability. Solar powered, too, so it's just an utterly reliable black box. My favourite gadget by far.

Radio syncing isn't available in my country (no local transmitter and too remote to pick up other countries) so phone sync is preferable for me.

Re: Casio-F-91W die-shot

#122

Post by ashwinne »

vasqw wrote: post #12

I bought one of those recently and I was surprised by how inaccurate it was. It drifted like 15 seconds every month. From what I've been reading, that is normal, but I was surprised - with all the technological advances that we have it is odd to think that cheap timekeeping is not a solved problem yet! Also: how is the software of these watches without a CPU designed? Is it something like Verilog or whatever?

I was surprised by this inaccuracy too. But was impressed when I learnt that there is no analog wristwatch that can match this accuracy - they are all far far worse. (Isn't it shocking that all those super-expensive Rolexes and whatnot are all going off by minutes per month!) Get one of the Casio watches that syncs to atomic clock radio signals every night - it will be second-accurate all the time.

Re: Casio-F-91W die-shot

#123

Post by lmz »

somat wrote: post #89
vasqw wrote: post #12

I bought one of those recently and I was surprised by how inaccurate it was. It drifted like 15 seconds every month. From what I've been reading, that is normal, but I was surprised - with all the technological advances that we have it is odd to think that cheap timekeeping is not a solved problem yet! Also: how is the software of these watches without a CPU designed? Is it something like Verilog or whatever?

A fair assessment, but I find it funny that 15 seconds per month is considered inaccurate, analog watches would kill for that sort of accuracy, a railroad quality pocket watch for example must loose no more than 30 seconds per week. I would guess that as smartphones are replacement for the pocketwatch, The way their network connected, never drift clock works becomes the new normal. I have to admit, for my day to day…

You mean Mechanical watches, not Analog ones. There are lots of Analog quartz watches with 15s/month accuracy.

Re: Casio-F-91W die-shot

#124

Post by ashwinne »

vasqw wrote: post #33
sn_master wrote: post #22

Earlier quoted context omitted.

> all the technological advances that we have This is 34 years old technology. You can get GPS watches relatively cheap and they'd sync with satellites automatically and always remain accurate.

Yes. I ended up buying a GWM5610 which synchronises through radio. It's cool. But still I would have hoped there would be a better "local" (i.e. self-reliant) solution.

Last year I switched to the GWM5610 after a long search. It perfectly fit my needs - accurate all the time (syncs to atomic clock radio signals), never needs a charge (solar powered) and is indestructible. What more could a nerd want!

Re: Casio-F-91W die-shot

#125

Post by kowbell »

_HMCB_ wrote: post #47

Looks like a city from overhead. Amazing.

Funny timing: I saw Koyaanisqatsi for the first time tonight, and there’s a section where it cuts from satellite images of a city to microchips (https://youtu.be/RSINqSvSVyM?t=402)

It made me want to look up more pics of chips, but after not getting good results searching on my own I gave up and came to HN... only to immediately see this post :)

Re: Casio-F-91W die-shot

#127

Post by Maursault »

somat wrote: post #89
vasqw wrote: post #12

I bought one of those recently and I was surprised by how inaccurate it was. It drifted like 15 seconds every month. From what I've been reading, that is normal, but I was surprised - with all the technological advances that we have it is odd to think that cheap timekeeping is not a solved problem yet! Also: how is the software of these watches without a CPU designed? Is it something like Verilog or whatever?

A fair assessment, but I find it funny that 15 seconds per month is considered inaccurate, analog watches would kill for that sort of accuracy, a railroad quality pocket watch for example must loose no more than 30 seconds per week. I would guess that as smartphones are replacement for the pocketwatch, The way their network connected, never drift clock works becomes the new normal. I have to admit, for my day to day…

> analog watches would kill for that sort of accuracy

Seiko 5 automatics have been reported to lose 30 seconds a month, even as little as 12 seconds a month.

Re: Casio-F-91W die-shot

#128

Post by petodo »

jojobas wrote: post #86

> Casio F-91W is an iconic watch worn (among others) by Barack Obama and Osama bin Laden. This escalated quickly.

it's infamous for being used by terrorists to build IED thanks to its accuracy and durability (same goes for Toyota Hilux), I think it's notoriety went that far that if you worn it at airport you might have been selected for random security check, though not sure if this part is truth or myth

Re: Casio-F-91W die-shot

#129

Post by Maursault »

ashwinne wrote: post #122
vasqw wrote: post #12

I bought one of those recently and I was surprised by how inaccurate it was. It drifted like 15 seconds every month. From what I've been reading, that is normal, but I was surprised - with all the technological advances that we have it is odd to think that cheap timekeeping is not a solved problem yet! Also: how is the software of these watches without a CPU designed? Is it something like Verilog or whatever?

I was surprised by this inaccuracy too. But was impressed when I learnt that there is no analog wristwatch that can match this accuracy - they are all far far worse. (Isn't it shocking that all those super-expensive Rolexes and whatnot are all going off by minutes per month!) Get one of the Casio watches that syncs to atomic clock radio signals every night - it will be second-accurate all the time.

> But was impressed when I learnt that there is no analog wristwatch that can match this accuracy

Seiko 5 automatics apparently[1] can.[2]

[1] https://www.watchuseek.com/threads/seiko-5-is-pretty-accurat...

[2] https://qr.ae/prvf6L

Re: Casio-F-91W die-shot

#130

Post by lmz »

dougSF70 wrote: post #52
jimmyjazz14 wrote: post #48

Earlier quoted context omitted.

I don't really understand your comment about avoiding Seiko (and yes as a Seiko collector I'm a bit triggered). In my experience Seiko makes absolutely great quality watches still with maybe the only issues generally being the occasional misaligned chapter ring though I pretty much only collect Seiko mechanical watches so maybe the situation is different with their quartz watches. Citizen also makes some particularly…

Seiko 5 automatic movement is on a par with the Rolex automatic movement according to my friend who is an official Rolex repairer.

Well they're both Automatic mobements with a Swiss lever escapement design, but the Rolex is finished better and has better balance adjustment (free-sprung balance). It is also factory adjusted as opposed to the Seiko 5 movement.
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