Muxcard, a dyi credit card size computer (github.com)

194 points by sargstuff 3 days ago

46 comments:

by realo 11 minutes ago

Very cool! Love it...

But...

The battery is likely to be squeezed quite a bit after this is put in my wallet, and in my pocket.

Lithium batteries do not like to be squeezed. They tend to signal their distress with some type of heat, usually accompanied with a small fire and probable smoke as well.

A distressed battery is very insistent upon everyone to see it's state of mind...

by mabster 2 hours ago

I went to the page expecting to rant about how it's not actually credit card size because of the thickness and was for once pleasantly surprised! Kudos to the author! It looks great!

by cbdevidal 5 hours ago

What fun!

I’d love to also go the opposite direction, a full-sized laptop with an ESP32 running tiny386 and Windows 95 ^_^

https://www.hackster.io/news/he-chunhui-s-tiny386-turns-the-...

by asdefghyk 7 hours ago

This post - the title made me remember ... ( as a credit card is about the same size as a business card )

A Linux Business Card CD is a miniature, credit-card-sized optical disc containing a stripped-down, bootable Linux operating system. They hold around 50MB to 100MB of data and were highly popular in the early-to-mid 2000s

More info at https://en.wikipedia.org/wiki/Bootable_business_card

by hantusk 6 hours ago
by WillAdams 3 hours ago

Or the Rex 6000 or other PCMCIA cards:

https://en.wikipedia.org/wiki/REX_6000

by devmor 2 hours ago

These things were cool! I believe I had some drivers installed via some of them, and a Kubuntu livecd.

by mmmehulll 5 hours ago

this is really cool. I didn't know we had these

by lxgr 3 hours ago

> A fully working computer that is literally the size of a credit card.

Nit: A (chip) credit card is already a fully working computer :)

by ZiiS 2 hours ago

Only if it is inside a specially designed radio field and with no independent IO. Feels like a battery and IO justify the 'fully working' differentiation.

by deckar01 33 minutes ago

Prologium is screen printing solid state batteries onto flexible ceramic insulators. They have some demos of single cells that appear to be thinner than 1mm continuing to operate after bending in half.

https://prologium.com/tech/core-technology/

by krauseler 4 hours ago

Developer here :)

Just saw this and love how I got the 100th or so "Does it run DOOM?". Even now officially an issue on GitHub. Does that mean I now have to deliver?

by Muhammad523 4 hours ago

> Does that mean I now have to deliver? Well, if you'd like to, you're free to do so! If not, somebody else could do it. You're not your audience's slave

I know it was intended as a joke but still..

by IAmBroom 2 hours ago

So... it's not DOOM-complete?

Teenage Alan T. would be so disappointed... :D

by gnabgib 3 days ago

Last week (87 points, 7 comments) https://news.ycombinator.com/item?id=48251528

by z3ugma 3 hours ago

Hidden in here is the coolest part, that the author made flex PCBs at home

by firesteelrain 3 hours ago

Just in time for DEFCON. We built many of these types of badges

by acrophiliac 14 minutes ago

dyi = Do Yourself It?

by inflam52 3 hours ago

I love these kind of projects. M5Stack Cardputer Zero launched on Kickstarter last week and already hit their goal

https://www.kickstarter.com/projects/m5stack/cardputerzero

by WithinReason 4 hours ago

Coincidentally, the xteink x4 has the same CPU, an e-paper screen and is close to credit card sized.

by zb3 an hour ago

__This__ is where all those trusted app parts should go - a smart card with e-ink display that can provide high security assurance level and where I won't mind that it's locked down because it has only one purpose.

__Not__ to my smartphone, effectively preventing me from modifying the system in the name of security. A banking app can use a card like this and on the display I could for example see where a transaction would go and then I could accept it, possibly even with a biometric identification.

This would enable me to keep my smartphone customizable and banking apps secure at the same time.

[apologies for the rant]

by rbanffy 6 hours ago

I would love if the screen could take up more space, even at the expense of a little extra thickness.

by WithinReason 4 hours ago

That actually exists, with even the same CPU but no NFC: https://www.xteink.com/products/xteink-x4

by jansan 6 hours ago

I think that there could be a wider screen if such formats are available. Once we have betavoltaic batteries, the entire card can be screen.

by mmmehulll 5 hours ago

love this. would be cool if we can see and perform all kinds of banking txns on this. Think ledger but all in one card. Super cool. Even cooler would be card to card money transfer without use of swipe machines

by resonious 5 hours ago

If "ledger on card" interests you, then you might enjoy Japan's FeliCa cards. They store balance locally on the card so you can pay very quickly, no network required.

by frankest 3 hours ago

Try NGK EnerCera for battery.

by fph 5 hours ago

How do you recharge it? Do you have to swap the battery?

by krauseler 4 hours ago

Hey, developer here :)

I used an ultra thin LiPo, so you can actually charge it. USB is obviously not an option but it uses magnetic pogo pins on the back side ^^

by stavros 4 hours ago

This is great, and I love it, and I hate to be saying this, but it's not literally the size of a credit card, it's 0.2mm thicker.

by krauseler 2 hours ago

Fair enough, but I acknowledged that and it's 0.24mm thicker if we want to be exact. Here's a quote from my Git Repo:

"Official ISO7816 smartcards are specified at 0.76mm thickness, but many real-world cards slightly exceed this in practice. The target for this project was simple: Stay around ~1mm total thickness and preserve the illusion of a normal card."

by voidUpdate 7 hours ago

It seems like it might be a little expensive for a business card...

by bird0861 4 hours ago

Let's see Paul Allen's card.

by ohlookcake 6 hours ago

Can it run DOOM?

by krauseler 4 hours ago

I've got the question like 100 times easily, and I love it.

And yes, if you accept ~0.7FPS

by iberator 5 hours ago

Run Unix v6 on it :) 16 bit and works with like 80kb of ram

by mrbluecoat 4 hours ago

First thought: cool! Second thought: e-waste

(same reaction as single-serve coffee pods, circa 2023)

by krauseler 4 hours ago

Good point. Ideally it would be the opposite of waste if it can save you from several cards. But banks would never certify such a multi-card system unless a big company pushes it forward.

Otherwise I'm sure people might use this to hack some terminals :P

by thenthenthen 5 hours ago

Do yourself it!

by aa-jv 5 hours ago

I want this, but only for one thing: email.

I already use an pwnagotchi, and it works great for this - but its a bit bulky.

If I can get this set up and working, it'll be my main interface to email.

by suzukivenom 6 hours ago

legendary

by goodpoint 5 hours ago

It's not a computer.

by bigfishrunning 3 hours ago

In what way is it not a computer?

by cbdevidal 5 hours ago

It’s got more horsepower than my first desktop computer

by krauseler 4 hours ago

Right, it doesn't compute. Apologies for the lie.

by antonvs 3 hours ago

Your definition of "computer" is incorrect.

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