9 ms·

Introducing the GoodWatch

604 points by limmeau 9y ago

codinghorror 9y ago
Oh my gosh this is amazing, such a labor of love. Everyone clearly needs a reverse engineered disassembler on their wrist.
- passwordqq2 9y ago
  I was going to leave a snarky comment about "reverse engineered disassembler" but then accidentally saw the username. What do you mean by that?
  - tazard 9y ago
    I would assume he's referring to the MSP430 disassembler built into the watch so you can reverse engineer the watches hardware, as it says in the article.
    - unwind 9y ago
      That was awesome but that is a reverse engineering disassembler (a bit redundant when the GoodWatch guy wrote the code to begin with but ...). A reverse engineered disassembler would be a disassembler that has been reverse engineered itself, which was not what the article said. It confused me, too.
  - mistermann 9y ago
    You might want to be more mindful of snarkiness, with Google's help you'll know why, I'd hope.
    - passwordqq2 9y ago
      Read unwinds's reply Mr smartass
limmeau 9y ago
At first I thought this was a firmware mod for those calculator watches, but it's a new circuit board. Comparable in power to those TI msp430 developer watches, but with better UI possibilities.
omn1 9y ago
I miss posts like this on HN.
- bastijn 9y ago
  Came here to reply: “this is why I read HN.”. Glad to see more people feel like that. @author (if here). Thanks, fantastic read and an even better gadget. You made me feel “O my, I need this!”.
  - ZenoArrow 9y ago
    If this why you read HN, I'd suggest checking out Hackaday, which gives you new content along these lines pretty much every day. Would recommend checking out both the Hackaday blog and Hackaday.io. The blog covers news articles about hacks, and Hackaday.io is a place where a community of hackers share their own projects: https://hackaday.com/blog/ https://hackaday.com/blog/ https://hackaday.io/ https://hackaday.io/ The main negatives I could say about Hackaday is the comment section on the blog is frequently a waste of time, and the UI of Hackaday.io could do with some improvements (IMO), but there's plenty of interesting projects to check out, and it's easy to ignore the comments section.
    - throwanem 9y ago
      Hackaday is indeed great for finding out about neat projects. Don't read the comments, though. Everyone is hobbying wrong and they need to know it right now.
      - ZenoArrow 9y ago
        Agreed, the comments sections on the blog probably the worst part of HaD. Very low signal to noise ratio. The main content makes up for it IMO.
      - sowbug 9y ago
        Post more Hackaday articles here.
j7ake 9y ago
So it will be possible to buy one ? It looks cool
- exikyut 9y ago
  It would be pretty cool for someone to step up and make a few of these, but they would need to be prepared to be mildly inundated with orders. Someone should tell Casio about this, and forward them http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv018.cgi?read=139415 http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv018.cg... as an example of what can happen when insiders successfully pull strings. In this particular case the poster in the linked thread worked deep inside HP and lobbied hard to get an SDK released and manufacture the calculator with a nondescript set of pins inside the battery compartment that permitted reflashing. The result was the "WP 34s" firmware: https://commerce.hpcalc.org/34s.php https://commerce.hpcalc.org/34s.php is a basic overview (unknown if clicking Order works, email first) and https://sourceforge.net/projects/wp34s/ https://sourceforge.net/projects/wp34s/ has full source code, details - and emulators for Linux/Windows/macOS that Just Work™, I might add. This firmware was written from scratch - the SDK provided a functioning compiler and basic architectural info about the calculator, but no sample code. The above firmware was thus written entirely from scratch. It implements all standard functionality (re-implements, heh) as well as a number of advanced fan-built features (more info at the SF link above). IIUC, the HP-20b is sadly no longer in active production, so getting one's hands on this interesting bit of kit is tricky. But despite the fact that this never really made headline news the whole venture worked perfectly. Thought I'd mention it. As for what I think Casio should do: the TL;DR is that it's really, really hard to do things that are offensive or damaging from a business standpoint with a 8-char 7-segment LCD and a tiny keypad. This isn't a smartwatch with a full-color LCD. So there's that. The real problem is that, well, what little market demand is left for wrist calculator watches is now split between the option of purchasing a smartwatch instead. So demand would be probably within the <2%-of-entire-market range. But if there happen to have any active production lines still producing these calculator watches, I can totally see Casio being able to very cheaply swap in a PCB with something like what OP has created. NB. Since I have no idea how far this comment could reach - by all means copypasta.
- mathgeek 9y ago
kelu124 9y ago
Superb!
vr46 9y ago
Wow. Everything about this is amazing, including the nostalgia from leafing through KMart catalogues of the 1980s for all the Casio watches.
- bringtheaction 9y ago
  Casio Wrist Camera digital watch Casio digital watch with built-in infrared remote for your TV Good times. Actually not very useful but they looked so hot back then and I remember just laying on the floor looking at the pictures of such watches.
  - Belphemur 9y ago
    It was quite useful to drive your teacher crazy when changing the volume randomly of the TV. That was so fun when I was a teenager.
jacquesm 9y ago
I absolutely love the work and the tone of this article. Very neat hack.
yoodenvranx 9y ago
This is one of those articles/projects where I really miss an established universal web-wide donation system. I just want to click a button on that page and send the author a few bucks as a Thank You for doing amazing things. (And no, a Paypal link is not an answer to this problem)
- bruncun 9y ago
  Have you considered the browser, Brave? Built-in micropayments. Https://brave.com
- sorenjan 9y ago
  Flattr tries to be that.
  - mistermann 9y ago
    Anyone know why it isn't more successful?
    - manigandham 9y ago
      People don't really care about (micro)payments and paypal actually does work just fine for one time events. Easier for people to list an email then signup for another service to get a few dollars. Also Flattr is owned by the Adblock Plus company now which has questionable history.
    - freeone3000 9y ago
      Their main business case got taken by Patreon, which is more popular due to more reliable income on the creator side.
- Aloha 9y ago
  I really want to build a micropayments system for stuff like this.
  - georgespencer 9y ago
ctkrohn 9y ago
Does anyone know what the apparently pocket-sized notebook computer is? The one in the picture about halfway through the post, with the watches draped over it.
- detaro 9y ago
  GPD Pocket: http://www.gpd.hk/pocket.asp http://www.gpd.hk/pocket.asp
  - craftyguy 9y ago
    well that's fucking sexy. now I want one.
    - sowbug 9y ago
      It delivers what it promises -- an unbelievably small Windows PC -- but there are four annoying things about it. First, the fan runs when it's charging. Every other device on Earth can charge silently when turned off. Second, the keyboard is not just small but also oddly arranged. Maybe some people can adjust to it, but for me, dear lord do I despise the letter Q when I'm using it. Third, there's something odd in the I/O that makes USB drives incredibly slow. The first thing I did was make a Windows 10 recovery drive on it (because I wanted to wipe it and run Linux). I kid you not, the operation took about 24 straight hours to complete. I haven't bothered profiling the system so I don't know where the bottleneck is. But it was a USB3 name-brand USB drive that I know is fast. Fourth, they claim Ubuntu runs on it, but they took the typical Shenzhen approach of putting a modified binary on Mega -- in this case an Ubuntu ISO -- rather than upstreaming their changes or publishing source code. No way in hell am I installing a binary download like that as my OS. Maybe they are in the process of upstreaming and a future pristine Ubuntu distro will run on it. Meanwhile I'm stuck with Windows 10 (and no, I'm not happy with that, either -- I have no way of knowing it's not rooted, either).
      - craftyguy 9y ago
        > Fourth, they claim Ubuntu runs on it, but they took the typical Shenzhen approach of putting a modified binary on Mega -- in this case an Ubuntu ISO -- rather than upstreaming their changes or publishing source code. Well, that makes this a no-go for me. Thanks for the info, seriously! > No way in hell am I installing a binary download like that as my OS Um, if you run windows 10 and install drivers from them, then you're running binary crap. (not to mention windows 10 is binary crap, but I digress)
larrydag 9y ago
You are the Q for Dick Tracy.
estevaovix 9y ago
This is neat!
brncsk 9y ago
So what's going on with those Hungarian words on the disassembler pic? :)
- sly010 9y ago
  I want to know the answer to that as well. Judging from travis's callsign (and name) he is based in the US.
VectorLock 9y ago
>What if you’re stuck in an hour-long SCRUM meeting and need to reverse engineer your watch’s firmware with pen and paper to retain your own sanity?” The worst of the worst meetings.
alunaryak 9y ago
This is a bit orthogonal, but if you're interested in the watch form factor, TI makes a really neat watch dev board for the MSP430 that has a built-in accelerometer and support for wireless sensors. http://processors.wiki.ti.com/index.php/EZ430-Chronos http://processors.wiki.ti.com/index.php/EZ430-Chronos
- dfox 9y ago
  I'm not sure whether Chronos is still in production. In comparison to this chronos is large (it is significantly larger that you would expect from the pictures) and it's radio capabilities are limited (not to mention that it does not have keyboard ;)) TI also for a short time made more advanced version with bluetooth, sane industrial design and certified radio which was quite similar to Pebble.
  - alunaryak 9y ago
    It's definitely getting long in the tooth, but I believe a few places still stock them. Mouser & Digikey both have a handful in stock. Mouser: https://www.mouser.com/search/refine.aspx?Ntk=P_MarCom&Ntt=182587955 https://www.mouser.com/search/refine.aspx?Ntk=P_MarCom&Ntt=1... Digikey: https://www.digikey.com/en/product-highlight/t/texas-instruments/ez430-chronos https://www.digikey.com/en/product-highlight/t/texas-instrum...
andrenotgiant 9y ago
Mirror: https://web.archive.org/web/20171216140013/https://goodwatch.org/posts/introducing-the-goodwatch/ https://web.archive.org/web/20171216140013/https://goodwatch... (can't find a mirror w/photos)
pmarreck 9y ago
This is definitely the geekiest, most awesome thing I will see today. Fantastic.
hexmiles 9y ago
That's pretty cool, I plan to do something similar but with a cheap smartwatch, a lot o Chinese smartwatch are based on the same soc family, and usualy are pretty hackable.
coupdejarnac 9y ago
Awesome project. I'm surprised we don't see more msp430-based watch projects. Bonus points for ham radio functionality. I'd be all over this if I didn't hate wearing a watch.
zoom6628 9y ago
I am sooo jealous of this. What an amazing project. Yes it would be front page on Hackaday but pleased it appeared here because HN is all about (IMHO) inventive and creative technology and its possibilities and applications. These sort of projects illuminate for the rest of us on what might be possible. Has inspired me to break open the boxes of parts i have and build something that works (useful or not remains to be seen), just to explore the possible. By day i work on Enterprise software, but ive had more inspiration moments when working on IoT wireless stuff at home than ever had in meetings, workgroups, or sitting in an office. To the author and creator, a huge thank you for the inspiration, education. Like one other poster mentioned i too would like a quick donate button for this. I do use for other projects because i think its important to acknowledge people who make stuff like this. Whether is code or hardware, or sometimes even just ideas on KS, give a few bucks if you can to share the fun and inspiration and reward others.
AlliedEnvy 9y ago
See also https://github.com/carrotIndustries/pluto https://github.com/carrotIndustries/pluto , a replacement board for the ubiquitous Casio F-91W, also using a TI microcontroller.
- zokier 9y ago
  That's pretty incredible, considering that f91w has such a small body.
wepple 9y ago
In case anyone loves this type of thing but hasn’t heard of PoC||GTFO, I encourage you to take a look: https://www.alchemistowl.org/pocorgtfo/ https://www.alchemistowl.org/pocorgtfo/
mmjaa 9y ago
I really wish the Oscilloscope Watch had made it through the hassle of production: http://www.gabotronics.com/oscilloscopes/oscilloscope-watch.htm http://www.gabotronics.com/oscilloscopes/oscilloscope-watch.... (Disclaimer: I'm one of the disappointed backers of his kickstarter campaign, which went nowhere...) If there were another attempt at making a watch like this one, I'd definitely be a backer. I think this is really an ideal time for someone to start up an open-source, powerful watch platform ..
dessant 9y ago
> It also has a hex editor, because no proper lady or gentleman should be caught in public without one on the wrist. I'll hold this thought dear for the rest of my life, thanks for sharing this amazing project.
tzs 9y ago
> It has ~5 years of battery life, knows days of the week for the next two thousand years, and has a handy RPN calculator. I wonder why two thousand years? All the common day of the week algorithms should work as long as the current leap year pattern [1] continues. [1] (year % 4 == 0) && ((year % 100 != 0) || (year % 400 == 0)

604 points by limmeau 9y ago

Oh my gosh this is amazing, such a labor of love. Everyone clearly needs a reverse engineered disassembler on their wrist.

passwordqq2 9y ago
I was going to leave a snarky comment about "reverse engineered disassembler" but then accidentally saw the username. What do you mean by that?
- tazard 9y ago
  I would assume he's referring to the MSP430 disassembler built into the watch so you can reverse engineer the watches hardware, as it says in the article.
  - unwind 9y ago
    That was awesome but that is a reverse engineering disassembler (a bit redundant when the GoodWatch guy wrote the code to begin with but ...). A reverse engineered disassembler would be a disassembler that has been reverse engineered itself, which was not what the article said. It confused me, too.
- mistermann 9y ago
  You might want to be more mindful of snarkiness, with Google's help you'll know why, I'd hope.
  - passwordqq2 9y ago
    Read unwinds's reply Mr smartass

limmeau 9y ago

At first I thought this was a firmware mod for those calculator watches, but it's a new circuit board. Comparable in power to those TI msp430 developer watches, but with better UI possibilities.

omn1 9y ago

I miss posts like this on HN.

bastijn 9y ago
Came here to reply: “this is why I read HN.”. Glad to see more people feel like that. @author (if here). Thanks, fantastic read and an even better gadget. You made me feel “O my, I need this!”.
- ZenoArrow 9y ago
  If this why you read HN, I'd suggest checking out Hackaday, which gives you new content along these lines pretty much every day. Would recommend checking out both the Hackaday blog and Hackaday.io. The blog covers news articles about hacks, and Hackaday.io is a place where a community of hackers share their own projects: https://hackaday.com/blog/ https://hackaday.com/blog/ https://hackaday.io/ https://hackaday.io/ The main negatives I could say about Hackaday is the comment section on the blog is frequently a waste of time, and the UI of Hackaday.io could do with some improvements (IMO), but there's plenty of interesting projects to check out, and it's easy to ignore the comments section.
  - throwanem 9y ago
    Hackaday is indeed great for finding out about neat projects. Don't read the comments, though. Everyone is hobbying wrong and they need to know it right now.
    - ZenoArrow 9y ago
      Agreed, the comments sections on the blog probably the worst part of HaD. Very low signal to noise ratio. The main content makes up for it IMO.
    - sowbug 9y ago
      Post more Hackaday articles here.

j7ake 9y ago

So it will be possible to buy one ? It looks cool

exikyut 9y ago
It would be pretty cool for someone to step up and make a few of these, but they would need to be prepared to be mildly inundated with orders. Someone should tell Casio about this, and forward them http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv018.cgi?read=139415 http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv018.cg... as an example of what can happen when insiders successfully pull strings. In this particular case the poster in the linked thread worked deep inside HP and lobbied hard to get an SDK released and manufacture the calculator with a nondescript set of pins inside the battery compartment that permitted reflashing. The result was the "WP 34s" firmware: https://commerce.hpcalc.org/34s.php https://commerce.hpcalc.org/34s.php is a basic overview (unknown if clicking Order works, email first) and https://sourceforge.net/projects/wp34s/ https://sourceforge.net/projects/wp34s/ has full source code, details - and emulators for Linux/Windows/macOS that Just Work™, I might add. This firmware was written from scratch - the SDK provided a functioning compiler and basic architectural info about the calculator, but no sample code. The above firmware was thus written entirely from scratch. It implements all standard functionality (re-implements, heh) as well as a number of advanced fan-built features (more info at the SF link above). IIUC, the HP-20b is sadly no longer in active production, so getting one's hands on this interesting bit of kit is tricky. But despite the fact that this never really made headline news the whole venture worked perfectly. Thought I'd mention it. As for what I think Casio should do: the TL;DR is that it's really, really hard to do things that are offensive or damaging from a business standpoint with a 8-char 7-segment LCD and a tiny keypad. This isn't a smartwatch with a full-color LCD. So there's that. The real problem is that, well, what little market demand is left for wrist calculator watches is now split between the option of purchasing a smartwatch instead. So demand would be probably within the <2%-of-entire-market range. But if there happen to have any active production lines still producing these calculator watches, I can totally see Casio being able to very cheaply swap in a PCB with something like what OP has created. NB. Since I have no idea how far this comment could reach - by all means copypasta.
mathgeek 9y ago

kelu124 9y ago

Superb!

vr46 9y ago

Wow. Everything about this is amazing, including the nostalgia from leafing through KMart catalogues of the 1980s for all the Casio watches.

bringtheaction 9y ago
Casio Wrist Camera digital watch Casio digital watch with built-in infrared remote for your TV Good times. Actually not very useful but they looked so hot back then and I remember just laying on the floor looking at the pictures of such watches.
- Belphemur 9y ago
  It was quite useful to drive your teacher crazy when changing the volume randomly of the TV. That was so fun when I was a teenager.

jacquesm 9y ago

I absolutely love the work and the tone of this article. Very neat hack.

yoodenvranx 9y ago

This is one of those articles/projects where I really miss an established universal web-wide donation system. I just want to click a button on that page and send the author a few bucks as a Thank You for doing amazing things. (And no, a Paypal link is not an answer to this problem)

bruncun 9y ago
Have you considered the browser, Brave? Built-in micropayments. Https://brave.com
sorenjan 9y ago
Flattr tries to be that.
- mistermann 9y ago
  Anyone know why it isn't more successful?
  - manigandham 9y ago
    People don't really care about (micro)payments and paypal actually does work just fine for one time events. Easier for people to list an email then signup for another service to get a few dollars. Also Flattr is owned by the Adblock Plus company now which has questionable history.
  - freeone3000 9y ago
    Their main business case got taken by Patreon, which is more popular due to more reliable income on the creator side.
Aloha 9y ago
I really want to build a micropayments system for stuff like this.
- georgespencer 9y ago

ctkrohn 9y ago

Does anyone know what the apparently pocket-sized notebook computer is? The one in the picture about halfway through the post, with the watches draped over it.

detaro 9y ago
GPD Pocket: http://www.gpd.hk/pocket.asp http://www.gpd.hk/pocket.asp
- craftyguy 9y ago
  well that's fucking sexy. now I want one.
  - sowbug 9y ago
    It delivers what it promises -- an unbelievably small Windows PC -- but there are four annoying things about it. First, the fan runs when it's charging. Every other device on Earth can charge silently when turned off. Second, the keyboard is not just small but also oddly arranged. Maybe some people can adjust to it, but for me, dear lord do I despise the letter Q when I'm using it. Third, there's something odd in the I/O that makes USB drives incredibly slow. The first thing I did was make a Windows 10 recovery drive on it (because I wanted to wipe it and run Linux). I kid you not, the operation took about 24 straight hours to complete. I haven't bothered profiling the system so I don't know where the bottleneck is. But it was a USB3 name-brand USB drive that I know is fast. Fourth, they claim Ubuntu runs on it, but they took the typical Shenzhen approach of putting a modified binary on Mega -- in this case an Ubuntu ISO -- rather than upstreaming their changes or publishing source code. No way in hell am I installing a binary download like that as my OS. Maybe they are in the process of upstreaming and a future pristine Ubuntu distro will run on it. Meanwhile I'm stuck with Windows 10 (and no, I'm not happy with that, either -- I have no way of knowing it's not rooted, either).
    - craftyguy 9y ago
      > Fourth, they claim Ubuntu runs on it, but they took the typical Shenzhen approach of putting a modified binary on Mega -- in this case an Ubuntu ISO -- rather than upstreaming their changes or publishing source code. Well, that makes this a no-go for me. Thanks for the info, seriously! > No way in hell am I installing a binary download like that as my OS Um, if you run windows 10 and install drivers from them, then you're running binary crap. (not to mention windows 10 is binary crap, but I digress)

larrydag 9y ago

You are the Q for Dick Tracy.

estevaovix 9y ago

This is neat!

brncsk 9y ago

So what's going on with those Hungarian words on the disassembler pic? :)

sly010 9y ago
I want to know the answer to that as well. Judging from travis's callsign (and name) he is based in the US.

VectorLock 9y ago

>What if you’re stuck in an hour-long SCRUM meeting and need to reverse engineer your watch’s firmware with pen and paper to retain your own sanity?” The worst of the worst meetings.

alunaryak 9y ago

This is a bit orthogonal, but if you're interested in the watch form factor, TI makes a really neat watch dev board for the MSP430 that has a built-in accelerometer and support for wireless sensors. http://processors.wiki.ti.com/index.php/EZ430-Chronos http://processors.wiki.ti.com/index.php/EZ430-Chronos

dfox 9y ago
I'm not sure whether Chronos is still in production. In comparison to this chronos is large (it is significantly larger that you would expect from the pictures) and it's radio capabilities are limited (not to mention that it does not have keyboard ;)) TI also for a short time made more advanced version with bluetooth, sane industrial design and certified radio which was quite similar to Pebble.
- alunaryak 9y ago
  It's definitely getting long in the tooth, but I believe a few places still stock them. Mouser & Digikey both have a handful in stock. Mouser: https://www.mouser.com/search/refine.aspx?Ntk=P_MarCom&Ntt=182587955 https://www.mouser.com/search/refine.aspx?Ntk=P_MarCom&Ntt=1... Digikey: https://www.digikey.com/en/product-highlight/t/texas-instruments/ez430-chronos https://www.digikey.com/en/product-highlight/t/texas-instrum...

andrenotgiant 9y ago

Mirror: https://web.archive.org/web/20171216140013/https://goodwatch.org/posts/introducing-the-goodwatch/ https://web.archive.org/web/20171216140013/https://goodwatch... (can't find a mirror w/photos)

pmarreck 9y ago

This is definitely the geekiest, most awesome thing I will see today. Fantastic.

hexmiles 9y ago

That's pretty cool, I plan to do something similar but with a cheap smartwatch, a lot o Chinese smartwatch are based on the same soc family, and usualy are pretty hackable.

coupdejarnac 9y ago

Awesome project. I'm surprised we don't see more msp430-based watch projects. Bonus points for ham radio functionality. I'd be all over this if I didn't hate wearing a watch.

zoom6628 9y ago

I am sooo jealous of this. What an amazing project. Yes it would be front page on Hackaday but pleased it appeared here because HN is all about (IMHO) inventive and creative technology and its possibilities and applications. These sort of projects illuminate for the rest of us on what might be possible. Has inspired me to break open the boxes of parts i have and build something that works (useful or not remains to be seen), just to explore the possible. By day i work on Enterprise software, but ive had more inspiration moments when working on IoT wireless stuff at home than ever had in meetings, workgroups, or sitting in an office. To the author and creator, a huge thank you for the inspiration, education. Like one other poster mentioned i too would like a quick donate button for this. I do use for other projects because i think its important to acknowledge people who make stuff like this. Whether is code or hardware, or sometimes even just ideas on KS, give a few bucks if you can to share the fun and inspiration and reward others.

AlliedEnvy 9y ago

See also https://github.com/carrotIndustries/pluto https://github.com/carrotIndustries/pluto , a replacement board for the ubiquitous Casio F-91W, also using a TI microcontroller.

zokier 9y ago
That's pretty incredible, considering that f91w has such a small body.

wepple 9y ago

In case anyone loves this type of thing but hasn’t heard of PoC||GTFO, I encourage you to take a look: https://www.alchemistowl.org/pocorgtfo/ https://www.alchemistowl.org/pocorgtfo/

mmjaa 9y ago

I really wish the Oscilloscope Watch had made it through the hassle of production: http://www.gabotronics.com/oscilloscopes/oscilloscope-watch.htm http://www.gabotronics.com/oscilloscopes/oscilloscope-watch.... (Disclaimer: I'm one of the disappointed backers of his kickstarter campaign, which went nowhere...) If there were another attempt at making a watch like this one, I'd definitely be a backer. I think this is really an ideal time for someone to start up an open-source, powerful watch platform ..

dessant 9y ago

> It also has a hex editor, because no proper lady or gentleman should be caught in public without one on the wrist. I'll hold this thought dear for the rest of my life, thanks for sharing this amazing project.

tzs 9y ago

> It has ~5 years of battery life, knows days of the week for the next two thousand years, and has a handy RPN calculator. I wonder why two thousand years? All the common day of the week algorithms should work as long as the current leap year pattern [1] continues. [1] (year % 4 == 0) && ((year % 100 != 0) || (year % 400 == 0)