11 ms·
Casio-F-91W die-shot
- Ecco 4y agoDumb question: is it legal to share a die shot like this one? What does copyright law say about this? I mean, yes, the author took the photo himself but what about the underlying material? Can I share a photo of an entire book? Do I own the copyright to a photo of a painting?
- petodo 4y agowhy not? you are free to disassemble your computer and take photo of motherboard or whatever hardware you have, I don't see how is taking photo of die different you can have copyright to your own photo, but not to pictured design
- Ecco 4y agoWell a die design, just like code, is definitely some form of intellectual property and covered by copyright law. So I think a more fair comparison would be a photo of an entire book.
- rwmj 4y agoIt might be a problem if the photo was reverse engineered into a schematic, which would also imply much more detail, but in this case it's just a photo of something cool.
- ekianjo 4y ago> Well a die design, just like code, is definitely some form of intellectual property and covered by copyright law. you can consume a book just by looking at it. You can't "read" a die-shot as easily.
- squarefoot 4y agoThe die design tells what parts are there, not their values or characteristics; cloning a chip just by looking at the die would require a lot more research.
- addaon 4y ago> is definitely some form of intellectual property and covered by copyright law I'm not sure if you meant to suggest that "some form of intellectual property" implies "covered by copyright law", but this is untrue in general, and untrue in this specific case. Copyright does not cover mask works; see [1] for discussion, from which quote: "Copyright law ONLY protects an original work of authorship IF the work is non-functional. But the etching designs on computer chips ARE functional." [1] https://revisionlegal.com/copyright/mask-works-101-copyright-protections-for-semiconductor-chip-products/ https://revisionlegal.com/copyright/mask-works-101-copyright...
- Taniwha 4y agoChip dies are covered by a special mask copyright law - you can actually see the M with a circle round it in this die photo (rather than the more traditional C with a circle)
- jonatron 4y ago"Can I share a photo of an entire book?" No is the short answer to that one.
- MonkeyClub 4y agoActually you can share a photo of an entire book - it's only that you can't share photos of all its individual pages as well... (Sorry, tried hard to resist, and failed.)
- bmurray7jhu 4y agoIn the US, semiconductor mask layouts are not eligible for copyright. Instead, the mask layout is protected under the Semiconductor Chip Protection Act of 1984. The Act grants rights similar to traditional copyright, but with a shorter period of protection and a more permissive framework for derivative works.
- userbinator 4y agoNotably, the "shorter period" is only 10 years.
- foota 4y agoInteresting, I imagine under normal copyright this would fall under fair use, does that exist for this as well?
- schemester 4y agoIf the layout had copyright protection, this would still be fair use.
- Ekaros 4y agoI don't think it is any different than taking a photo of your car engine or gearbox or any such component. Issues comes when you start to make copies.
- BarsMonster 4y agoYep, this is my understanding. Also, world practice shows that noone ever got into troubles for posting chip pictures, and in 10 years noone ever contacted me to remove any photos. But companies do get intro troubles for trying to do copycat chip production, although it is not always easy to prosecute.
- deleted 4y ago[deleted]
- diydsp 4y agoSeems like two large similar rectangular logic areas.... maybe one is state machine and one is display? Or maybe one is clock/date and one is UI?
- kens 4y agoI think it's one blob of standard-cell logic on the left with power routing through the middle. I don't think there is any visible partitioning into functionality in this logic. The large amount of analog circuitry in the right half is a bit of a puzzle. It looks like some large capacitors, maybe a charge pump for something?
- addaon 4y agoThis is outside my wheelhouse, but I assumed that the large capacitor area was a (trimmable) capacitor bank that could be put in parallel with the load capacitor on the (external) quartz oscillator, allowing calibration to counter some unit-to-unit variant in crystal frequency.
- kens 4y agoThat's a possibility, but I don't see any laser-trimming marks on the big capacitor. Another option would be selecting capacitors with fuses, but I don't see any fuses or capacitors with powers-of-two sizing. With the complexity of the circuitry in the right hand side, I think there are a bunch of analog things going on.
- makomk 4y agoThe calibration for quartz crystal variance in these watches is done much, much later in the manufacturing process using solder bridges on the PCB - people have reverse engineered it. I think there are watch oscillator chips out there with one-time programmable calibration (particularly for analog watches) though.
- vasqw 4y agoI 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?
- serf 4y ago>yet I mean, we have accurate electric timepieces now, and the F91-W came out in 1989; we had accurate electric timepieces then, too. it's a cost versus value thing.
- teraflop 4y agoIt's easy to make a digital circuit that counts clock cycles with perfect accuracy. But for any clock, the actual length of each cycle is dependent on analog processes, and it's impossible to completely eliminate errors. 15 seconds per month is about 6 parts per million, which is already better than the manufacturing tolerances of a typical cheap quartz crystal. There are very few objects of any kind that you can obtain cheaply with that kind of accuracy. That suggests that, as this article says, Casio is trimming the frequency for each watch to compensate for component variations.
- faisalhackshah 4y ago15 seconds per month is about 6.7ppm. That's well within typical crystal oscillator accuracy. If you need more than that (without external time correction such as gps or radio/internet), you need expensive oscillators with temperature compensation or even ovenized units.
- sn_master 4y ago> 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.
- 4y ago
- MonkeyClub 4y agoIs that a Swiss flag on the lower-left corner, or some kind of pads?
- faefox 4y agoMaybe a fiducial marker?
- lightedman 4y agoCorrect, this is an alignment fiducial for doping to ensure everything is in proper rotational alignment before masking and doping.
- qwezxcrty 4y agoMaybe an alignment marker for layer stacking.
- sweetjuly 4y agoYup! These sorts of crosses are used to align photolithography masks. Here's a similar example: https://www.seas.upenn.edu/~nanosop/images/alignmentmarks2.png https://www.seas.upenn.edu/~nanosop/images/alignmentmarks2.p... There are a lot of other structures used to characterize the alignment and other fancy structures which support machine alignment for newer (than like the 90s) processes.
- MayeulC 4y agoPossibly a (coarse, as it's the topmost) mask alignment target.
- mmaunder 4y agoI'm a big fan of the F105W which is basically the same watch with a vastly improved backlight that lights up the whole LCD. It makes a great watch extremely usable at night. I'd also recommend the Casio G-Shock GWM5610 which admittedly is about 5 times more expensive at $111 but it has UTC time and is absolutely bulletproof, along with radio sync and solar with solar charge indicator. It's currently my favorite among my modest under $200 collection of watches because it's so practical. I love unconnected watches because they tell the time and have a few other basic features without vendors competing for your eyeballs in constantly evolving ways. Side note: I'd avoid Seiko even though they kicked off the quartz crisis by launching the world's first quartz watch in 1969, their product quality is crappy these days with missing features on some nice looking watches, and some bugs in their mechanical movements. On a separate note, I find the luxury watch market to be quite hilarious (especially the pretentiously eloquent way a customer will describe their "acquisition") but I do keep an eye on it for fun and classics like the Rolex Sub Date have dropped by over 20% in price on the used market in the past 10 months (source is Chrono24 which charts prices). My guess is we'll see the used luxury market flooded in 2023/24 as extravagant purchases made during boom times are liquidated for cash.
- haunter 4y ago>radio sync Such and underrated feature! There is a good list of Multiband watches that works across multiple continents that way https://shockbase.org/function_page_dyn.php?function=multi_band_6 https://shockbase.org/function_page_dyn.php?function=multi_b...
- TedDoesntTalk 4y ago> F105W which is basically the same watch with a vastly improved backlight Can’t stress this enough. The F-91W is useless at night because the backlight brightness is terrible. The F105W has an indiglo-style “EL” light that is very effective. The two watches are nearly identical from an aesthetic perspective. The functions are identical as are the buttons.
- 3pac 4y agoIndiglo has good looks and function. What I dislike is that it requires a high-voltage driver. As tiny and low-current as that may be, it is electrically and even slightly acoustically noisy, and not something that belongs in a low-voltage wristwatch.
- aliljet 4y agoThis is a remarkably interesting image. How do these guys even get these shots? I'd love to do this on all kinds of things at home..
- sweetjuly 4y agoI really like this one Defcon talk on chip decapping [1]. It's a pretty nasty process but absolutely one you can do on your driveway (poor man's fume hood, don't tell the EPA) at home. You can then just use a standard front lit microscope to take die shots. [1] https://youtu.be/0Z4aF-qiziM https://youtu.be/0Z4aF-qiziM
- kens 4y agoFor die photos, you want a metallurgical microscope, one that shines light down through the lens. A typical microscope shines the light from underneath, which works well for biological samples, but not so well for chips. The tricky part is decapping the chip. The easy way is to get a ceramic package, which you can decap with a chisel. Or a metal can, which you can open with a hacksaw. With a standard epoxy package, you can heat it with a hot air gun and twist it, and you have maybe 50% chance of the die separating from a package. The best way for epoxy packages is boiling sulfuric and/or nitric acid, which has obvious issues. The other aspect is that you need to stitch together a bunch of images to get a high-resolution photo. I use Hugin, which lets just say that it has a learning curve.
- einpoklum 4y agoF-91W is the watch I wear today. Actually, my favorite wristwatch - or rather the one I wore for 25 years or so - was a W-71. Unfortunately, you can't buy these except as vintage second-hand. I still don't understand why that is... I always felt it a more "aesthetically-balanced" version of the F-91W; plus it had 4 buttons rather than 3, which makes sense given the structure both watches. But I lost my W-71 while moving out of my last apartment, so... now I've had to settle on the F-91W. Ah well.
- deleted 4y ago[deleted]
- tejohnso 4y agoI don't wear watches as I'm always either at my computer or have my phone with me, but if I did wear a watch, I would probably go with something like the F-91W. Images of it bring on a nice retro nostalgia, and I appreciate its blatant function over flair aesthetic.
- einpoklum 4y agoUmm, perhaps you haven't seen the W-71: https://duckduckgo.com/?q=casio+W-71&t=ffab&iax=images&ia=images https://duckduckgo.com/?q=casio+W-71&t=ffab&iax=images&ia=im... not exactly flair aesthetic.
- _HMCB_ 4y agoLooks like a city from overhead. Amazing.
- once_inc 4y ago"The Grid. A digital frontier. I tried to picture clusters of information as they traveled through the computer. Ships, motorcycles. With the circuits like freeways. I kept dreaming of a world I thought I'd never see. And then, one day... i got in."
- ckocagil 4y agoI guess you'll enjoy this one too: https://zeptobars.com/en/read/AD9361-SDR-Analog-Devices-DAC-ADC-65nm https://zeptobars.com/en/read/AD9361-SDR-Analog-Devices-DAC-...
- int_19h 4y agoThere's a reason why "circuit as a city" used to be a common visual metaphor in pop culture when computers came up. E.g. this scene from the Hackers: https://youtu.be/IESEcsjDcmM?t=135 https://youtu.be/IESEcsjDcmM?t=135
- kowbell 4y agoFunny 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 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 :)
- nickdothutton 4y agoCasio is an under leveraged brand. One of the few that could, I think, be taken into more product areas than it is currently. There's brand equity there they are not fully leveraging.
- daviddaviddavid 4y agoThough not a move into a completely different product area, it's been interesting to see them step up their digital piano game. For a long time it seemed like Casio had a reputation for not making serious keyboards that you could gig on. But they have been churning out really nice keyboards recently - most notably, the Privia line. The ones I've played have a really nice feeling action, pro-level sounds and they're visually quite slick.
- leetrout 4y agoI was shopping around for a digital piano and the Privia does look really nice. I haven't experienced one in person yet and I am a bit scared to buy any keyboard or digital piano without trying the action.
- daviddaviddavid 4y agoI like the action on the Privias (and the similar CDP360s, which I played recently). My only complaint about the action is that if you're playing at low/practice volumes, you tend to hear a lot of mechanical plastic sound as the keys spring back up. I'm a big fan of Roland's actions. I'd check out the FP30. I also used to practice on a Yamaha P125B and they are great.
- leetrout 4y agoThank you very much for the additional info!
- kube-system 4y agoI am always attracted to the design of Casio keyboards when I see one at a store somewhere. Then I play them, and realize that many of them (the low end models) still often lack velocity sensing. Both the best and the worst thing about Casio is that they’re stuck in the 90s.
- daedalus2027 4y agoDoes it run Doom?
- deleted 4y ago[deleted]
- BarsMonster 4y agoNot... yet :-)
- apricot 4y agoMaybe eventually: https://www.geeky-gadgets.com/casio-smartwatch-22-07-2022/ https://www.geeky-gadgets.com/casio-smartwatch-22-07-2022/ Gonna need some creative solutions for graphics rendering, though.
- libpcap 4y agoIs the F91W still manufactured in Japan?
- zichy 4y agoIt is made in China afaik.
- BarsMonster 4y agoI've seen some made in Thailand. I would expect chip itself & quartz oscillator made in Japan.
- deleted 4y ago[deleted]
- jojobas 4y ago> Casio F-91W is an iconic watch worn (among others) by Barack Obama and Osama bin Laden. This escalated quickly.
- petodo 4y agoit'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
- low_tech_punk 4y agoFrom the business/design/technology POV, why is this watch so successful and so iconic?
- panza 4y agoIt's durable, keeps good time, battery lasts 7-10 years, clear display, thin and light. It's incredible value for $15-25. Deserves to be as popular as it is.
- wkat4242 4y agoThe only real drawback is the terrible backlight which is fixed by the F-105W which has a soft blue EL backlight <3. Much preferable to the 91 IMO. Functionally both watches are the same.
- peter303 4y agoI have probably ten- not precisely the same model- in the past thirty years. Most common failure is strap breaks after taking the watch off for swimming every other day. Second most failure is to shatter a corner due sports- hit my wrist on something. Third is a humidity leak when I visit the US South in the summer.
- stoppingin 4y agoApologies for a silly question, what exactly are we looking at here? I've seen the inside of an F-91W, and I always imagined that under the black epoxy blob was some kind of off-the-shelf microprocessor (most likely 4-bit) with a mask ROM containing the watch's logic. Is the entire watch run from this IC, with no processor? If so that's really interesting.
- SnowHill9902 4y agoIf you are making millions of units for a RT application you definitely want custom silicon.
- stoppingin 4y agoIs this on account of cost, or simplifying verification? I was under the impression that minimising the overall risk of a design was a major consideration. I'd love to know more about how these design decisions were made.
- BarsMonster 4y agoPower consumption and cost. 10 years on a battery is very hard to achieve for microcontroller. https://sorwatch.net https://sorwatch.net shows that : with much more advanced microcontroller (much more modern tech.node, low power features) - it only works for 1-2 years on a single battery after extensive power optimizations. In custom silicon when seconds tick - it's maybe 100 transistors change their state. In microcontroller - it's roughly 10'000-100'000 transistors changing state to handle interrupt and update display content...
- deleted 4y ago[deleted]
- deleted 4y ago[deleted]
- t7s 4y agobest watch ever!
- henriquegogo 4y agoA piece of art.
- kreelman 4y agoHave a look at this. Joey built a whole swathe of sensors to plug in to a f-91W like circuit. https://hackaday.com/2022/02/24/remoticon-2021-joey-castillo-teaches-old-lcds-new-tricks/ https://hackaday.com/2022/02/24/remoticon-2021-joey-castillo...
- neilv 4y agoAlso non-sensor applications: https://blog.singleton.io/posts/2022-10-17-otp-on-wrist/ https://blog.singleton.io/posts/2022-10-17-otp-on-wrist/