11 ms·

System Bus Radio

499 points by sssilver 11y ago

xlayn 11y ago
I wonder if deployed around the world there is a network of radios sync by GPS to receive time encoded encrypted communications signals of every electrical powered devices configured to transmit according to the same principle and all the things about security are just a curtain behind the capability of capturing everything that has already been deployed. Given that this is CPU and subsystems related doesn't have anything to do with software running... it could be capture and executed by a routine in the CPU out of every possible observance by dedicated circuitry, this would fall under all the requisites mentioned by the poster Be emitted by the computer processor and other subsystems Escape the computer shielding Pass through the air or other obstructions Be accepted by the antenna Be selected by the receiver Neurosis off... Edit: Neurosis on You know what escapes computer shielding? cables... like the ones with cpus that are used for connecting to external devices... Neurosis off.
- exDM69 11y ago
  I recall seeing a cryptographic side channel attack based on radio frequency interference from the victim computer. I don't have a source for this but I'm sure someone will find a link soon enough.
  - mtreis86 11y ago
    I remember this being done with microphones, listening to the clicks of the coils. Related? http://www.cs.tau.ac.il/~tromer/acoustic/ http://www.cs.tau.ac.il/~tromer/acoustic/ Edit, found in one of the links on that page, seems this is the same group http://www.cs.tau.ac.il/~tromer/ecdh/ http://www.cs.tau.ac.il/~tromer/ecdh/
- lost_name 11y ago
  Is what you're looking to be paranoid about? https://en.wikipedia.org/wiki/Tempest_(codename) https://en.wikipedia.org/wiki/Tempest_(codename)
  - j_s 11y ago
    Also https://en.wikipedia.org/wiki/Van_Eck_phreaking https://en.wikipedia.org/wiki/Van_Eck_phreaking
    - Arubis 11y ago
      And thus, it's obligatory that someone recommend Neal Stephenson's _Cryptonomicon_, in which this features quite heavily.
      - ibmthrowaway218 11y ago
        And, within 24 hours or so someone will submit the Van Eck Phreaking Wikipedia page link as a standalone submission on HN.
        fabulist 11y ago
        As long as we're making tangential recommendations and expecting to be reintroduced to things within 24 hours, I'd like to throw John Dies at the End into the ring.
        raddad 11y ago
        RF leaks are an old tune, NSA was using it back in the 60's I believe. There was an article in Wired about this topic in 2008[0] Gene Hackman and Will Smith in a movie Enemy Of The State (2009)[1] hinted at this technology. [0] http://www.wired.com/2008/04/nsa-releases-se/ http://www.wired.com/2008/04/nsa-releases-se/ [1] http://www.imdb.com/title/tt0120660/?ref_=nm_flmg_act_10 http://www.imdb.com/title/tt0120660/?ref_=nm_flmg_act_10 (edit for formatting)
        adenner 11y ago
        it was already done ~86 days ago, so it won't be back for a bit longer https://news.ycombinator.com/item?id=10684447 https://news.ycombinator.com/item?id=10684447
        11y ago
- lallysingh 11y ago
  I feel like you've just written half of the script for the next Transformers movie.
- WillKirkby 11y ago
  There's this DEFCON talk that (among other things) covers how an unshielded display cable can potentially leak screen contents over RF. Well worth a watch if you've got the time. https://www.youtube.com/watch?v=_g9yUiAHiFo https://www.youtube.com/watch?v=_g9yUiAHiFo
- ikeboy 11y ago
  If this was true, you'd expect hobbyist radio operators to notice, right? That increases the required conspiracy size by orders of magnitudes.
  - xlayn 11y ago
    Out of the Neurosis joke area and in line with your hobbyist radio operator comment, probably the person who most know about how to perform radio transmissions using a component by re-purposing them are those who work shielding sensible components away from it. For example power bricks that contains every day more and more circuitry could implement a protocol of communication by de-modulating a message sent by AC and then sending via radio to the computer the message; process that's even easier with power cables with data lines.... like the usb cable.
pierrec 11y ago
"Different results will be achievable with different equipment. Please send your results to sbr@phor.net" I think the barrier to entry for this is raised by the fact that most people don't have AM receivers anymore. If I find one lying around though, I will certainly give this a try. Ah, and apparently this proof-of-concept works exclusively on OSX for now.
- croddin 11y ago
  Almost all cars still have them, just bring a laptop into a car.
  - devy 11y ago
    BMW i3 has the AM hardware builtin but disabled it in firmware [1] due to the exact same reason: electromagnetic interferences caused poor quality of the AM reception. Obviously, AM radio on i3s can be re-enabled by firmware hacking - called "coding". [2] Even with the full metal body/frame, AM radio noise caused by EMI emitted from EV motor/circuits was still significant. I guess it's still VERY HARD to shield these EMIs. Full disclosure: I've owned BMW ActiveE and BMW i3. [1] http://www.greencarreports.com/news/1098893_bmw-i3-electric-car-quirk-no-am-radio--but-why http://www.greencarreports.com/news/1098893_bmw-i3-electric-... [2] http://www.greencarreports.com/news/1099782_bmw-i3-rex-electric-car-coding-unlocks-features-owners-want-and-may-void-warranty http://www.greencarreports.com/news/1099782_bmw-i3-rex-elect...
    - mikeash 11y ago
      The Tesla Model S has AM. It's fun to tune the radio to an unused frequency and drive around. The radio picks up a ton of noise that sort of emulates just a little bit how a loud gasoline engine would sound. I hear that they've removed AM from the Model X.
      - devy 11y ago
        The radio picks up a ton of noise that sort of emulates just a little bit how a loud gasoline engine would sound. It's the same behavior in BMW EVs(i3/i8/ActiveE/MiniE). It's not a constant noise on AM radio but really when you press the accelerator pedal hard on a quiet street could you hear the interference. BMW consider that unacceptable based on their "standards". Apparently a lot ofTesla Model S owners agree with BMW on the subpar AM radio reception and complaint on their forum[1], which was probably why AM radio removed from Model X. I do consider that a surprise feature (of emulating engine revs) albeit it's a bit annoying sometimes. [1] https://forums.teslamotors.com/forum/forums/am-radio-stations-make-whir-sound-car-accellerates-and-slows https://forums.teslamotors.com/forum/forums/am-radio-station...
dwyerm 11y ago
This is probably the wrong reaction to this article, but it is mostly making me nostalgic for the distinctive musical RF interference that comes from a C64 while it is in a FOR delay loop.
- amyjess 11y ago
  That's not the only part of the C64 you could make music out of. My co-worker told me of a program he downloaded from a BBS back in the day called "Drive Music" that turned his C64's floppy drive heads into a musical instrument.
  - threeio 11y ago
    https://www.youtube.com/watch?v=5gnMgmlKi_o https://www.youtube.com/watch?v=5gnMgmlKi_o
    - beamatronic 11y ago
      I had this! It was amazing but IIRC it came with a disclaimer that you may need to re-align your drive heads afterwards.
TerryADavis 11y ago
The longer you fight God, the worse it gets, silly nigger. God says... entourages Regina's doggoning functions adjudicate Getty righteously hoarseness's winterizes czars flyleaf justness's impromptu's collectibles servitude rinse averages sympathize inquest McGowan's grandeur's Richelieu's scooting ostensible boggiest exhibitor rockers nostrils blooms saddle's piddle cavalry
jmount 11y ago
Neat. In the 1970s there was a program that triggered the S100 bus of the time and played Flight of the Bumble Bee on a nearby radio.
- dbcurtis 11y ago
  Ha Ha! Yes. I was thinking the same thing. My old college roomie had an old 8080 system (Cromemco??? I can't remember.. it was the pre-Apple II days...) and used to run that program and similar radio noise makers. I think there was some space game that used bus noise for weapon effects.
  - jmount 11y ago
    Mine was IMSAI 8080. But I had forgotten- I think one of the Star Trek games did the phasers on the radio.
calebm 11y ago
Wow, if this works, that is awesome!
calebm 11y ago
Just tested on a MacBook Pro (Retina, 15-inch, Late 2013) and it didn't work. (Although I see in the README it says to run it on an Apple MacBook Air 13-inch, Early 2015). Anyone else get it to work?
- fulldecent 11y ago
  Thanks for your feedback. Even different models of the same computer will have different results. But I suspect that the MBPR you have will likely still work. Please check different AM channels and put the antenna directly on the computer to get started. If you find another frequency that works please let me know (email on the project page).
- thought_alarm 11y ago
  Works for me on an Early 2014 MacBook Air and Mid 2011 iMac, although the iMac signal is very, very weak.
- klagermkii 11y ago
  Works here on a Retina 15-inch mid-2012 MacBook Pro. You've got to have the antenna real close to the machine (talking 10 cm here), turn the dial pretty much to the end of the AM band and then you can hear the tune through loads of AM static.
- calebm 11y ago
  UPDATE: This DID work for me on my MacBook Pro (Retina, 13-inch, Late 2013). Nicely done @fulldecent!
- whyleyc 11y ago
  Works fine on my MacBook Pro Retina, 13-inch, Early 2015. Quite a lot of static, but an amazing moment when you do pick out the tune for the first time !
- ultrafez 11y ago
  Working on a mid-2012 15" non-retina MBP. I was able to pick up the tune on various frequencies, starting around 650khz and on various other bands right up to around 1500khz (my radio's upper limit).
FreeFull 11y ago
There also used to be a program that would transmit audio over radio waves using a CRT monitor.
- FreeFull 11y ago
  Here it is: http://www.erikyyy.de/tempest/ http://www.erikyyy.de/tempest/
throwaway21816 11y ago
RIP Airgap
deleted 11y ago
[deleted]
- voctor 11y ago
  Replacing _mm_stream_si128 with a simple x++ will work too.
corysama 11y ago
Somewhere out there is the story of the guy who brought his Alto computer and electric guitar to the infamous Computer Club. He set the guitar on the computer and the speaker started playing Mary Had A Little Lamb. He had written a program to set and unset registers at specific frequencies.
- eliteraspberrie 11y ago
  This is how we got sound to play on the TI graphing calculators. It sounded bad and drained the batteries but it was fun. Another fun thing was getting grayscale graphics on those screens. They had only black and white pixels but flipping them on and off at different frequencies made them gray.
- stevetrewick 11y ago
  According to Steven Levy's 'Hackers'[0] it was Steve Dompier's Altair, it was a radio not a speaker, and the tune was the Beatles' Fool on the Hill. [0] Which it turns out is online at http://www.gutenberg.org/cache/epub/729/pg729.html http://www.gutenberg.org/cache/epub/729/pg729.html
  - GFK_of_xmaspast 11y ago
    Question to Radio Yerevan: "Is it correct that Grigori Grigorievich Grigoriev won a luxury car at the All-Union Championship in Moscow?" Radio Yerevan answered: "In principle, yes. But first of all it was not Grigori Grigorievich Grigoriev, but Vassili Vassilievich Vassiliev; second, it was not at the All-Union Championship in Moscow, but at a Collective Farm Sports Festival in Smolensk; third, it was not a car, but a bicycle; and fourth he didn't win it, but rather it was stolen from him."
    - nine_k 11y ago
      (The canonical version says something like "The information is generally correct, but subject to four adjustments".)
jpalomaki 11y ago
What about receiving these communications using computer without special hardware? Could this interfere with audio, wifi or some other component in away that could be detected by software? Quite certainly decent bit rates would be out of question, but would it be possible to pass any information between two computers using this?
- mafuyu 11y ago
  It would certainly be very difficult. If you could get the bus noise near the 2.4GHz freq range (unlikely), you could use the wifi of the other computer to potentially receive. Another thing people have experimented with is using the speaker/microphone at above human hearing range. This method usually falls flat because crappy laptop speakers have a hard time going above 20kHz. One thing I could potentially see working is a laptop with a hard drive generating vibrations with the motor. Then, a smartphone or laptop with an accelerometer could pick up the signal using the coupling through a table.
  - simcop2387 11y ago
    Wifi being so high bandwidth it'd be very difficult. Bluetooth Low Energy supports very small bandwidths and would be significantly easier to generate in the end. You generally don't get good enough control over the motors or voice coil in a hard drive to be able to make vibrations like that. I'd probably look at controlling the fans instead to get a similar effect and use the microphone to listen for the noise from them.
    - mafuyu 11y ago
      I was thinking along the lines of hard drive spin down/spin up due to power state configurations. The fans would probably be easier, though, provided you could pick up on it.
    - 21 11y ago
      There are videos on youtube with people making hard drives "sing" by carefully computed seek actions.
Kinnard 11y ago
Fascinating!!!
y04nn 11y ago
It's what have been done in 1977 on the MITS Altair 8800 by Steve Dompier at the Homebrew Computer Club. The beginning of the personal computer history.
- kw71 11y ago
  We did this on the zx81 too. I think there was a game that used an AM radio for sound. It was certainly written up in the contemporary computer magazines. I guess this will be rediscovered every time someone happens to figure out timing loops while they have a radio nearby.
hookshot 11y ago
Worked great on my MacBook Air (13-inch, Early 2015) with an old panasonic boombox. Very cool!
ramgorur 11y ago
I am in kind of dark here, where is the antenna? the wires on the system bus? or the copper coil in the speaker? could someone please explain it a little bit more?
- jhallenworld 11y ago
  It's just leakage. Any high power component which can be controlled by the program is likely to do it. Remember that the radio receiver's gain is essentially infinite- the limit is the noise floor. If there is any leakage above the noise floor, you are going to pick it up. There are lots of related tricks: tune a communications receiver to 455 KHz, and you will pick up the station that a nearby radio is receiving (because it's picking up IF leakage). Also the inverse works: the IF amp is where all the gain is, so if you transmit on 455 KHz, you can jam nearby AM radios no matter what they are tuned to. My dad did this when he was a kid in the 40s with a single tube transmitter.
- slug_tro_AWAY 11y ago
  Any oscillating electric current transmits magnetic waves of a certain strength. Certain oscillations at particular frequencies represent radio waves. At lower frequencies, one might merely act directly upon the magnetic transducers of a poorly-shielded audio speaker, creating sounds at volumes and within ranges audible to humans. Any segment of electric wire, carrying a current that can change direction, might be used to this effect. Stronger electrical activity over a bigger, better wire has higher chance of sending a signal that can be detected.
hansjorg 11y ago
Very interesting. Reminds me of a similar project from Fabrice Bellard, using a VGA card to broadcast a DVB-T digital television signal: http://bellard.org/dvbt/ http://bellard.org/dvbt/
- Swannie 11y ago
  Thanks, this was at the edge of my memory, but I was struggling to recall :-) I think Fabrice's demo is much more interesting, as it's significantly denser information.
soheil 11y ago
I did something similar back in the day using CRT monitors that displayed the right image at the right time to produce desired radio waves. The range was very limited, however, and lots of background noise but you could certainly hear the music that was playing if you tuned your radio and brought it real close to the monitor.
kens 11y ago
Generating music via radio interference goes way, way back. The IBM 1401 (1960's era) could do this:https://www.youtube.com/watch?v=EPk8MVEmiTI https://www.youtube.com/watch?v=EPk8MVEmiTI It could also play music on the line printer by banging out the right sequence of characters. http://mail.computerhistory.org/pipermail/1401_software/2009-February/000289.html http://mail.computerhistory.org/pipermail/1401_software/2009... Strangely, the 1401 radio music was later set to orchestra and released as a CD by an Icelandic composer: http://www.npr.org/templates/story/story.php?storyId=7408766 http://www.npr.org/templates/story/story.php?storyId=7408766
- RachelF 11y ago
  Back in the early 1980's this was the standard way to produce sound on the (Timex) Sinclair ZX80.
- semi-extrinsic 11y ago
  Old HP scanners used to have a music-making easter egg: http://youtu.be/8JwU5mcIwDw http://youtu.be/8JwU5mcIwDw
- alanh 11y ago
  In the vein of old hardware playing music, you should absolutely check out this cover of Radiohead’s “Nude,” if this sort of thing interests you. I find it strangely moving. http://alanhogan.com/big-ideas-dont-get-any http://alanhogan.com/big-ideas-dont-get-any (direct link http://www.vimeo.com/1109226?pg=embed&sec=1109226 http://www.vimeo.com/1109226?pg=embed&sec=1109226)
chrischen 11y ago
Can this read other data in the system bus?
peterwwillis 11y ago
Andrews Airforce Base's Emission Security Information Guide https://web.archive.org/web/20011117002220/http://www.andrews.af.mil/89cg/89cs/scbsi/emsecguide.doc https://web.archive.org/web/20011117002220/http://www.andrew...
jventura 11y ago
For those that do not have a Mac or AM radio, I made a small video for you: https://youtu.be/oXAeGZaka7o https://youtu.be/oXAeGZaka7o It's a Macbook Pro late 2013 and a pretty stock FM/AM radio.
- JetSpiegel 11y ago
  https://www.youtube.com/watch?v=Nroc2BtO6NU https://www.youtube.com/watch?v=Nroc2BtO6NU There's already a PR with Linux support, it works! There's another PR to play the Super Mario theme, that also works.
  - kefka 11y ago
    I won't be one of the cool kids and make a video but; Thinkpad T61 works with the Linux branch.
  - jventura 11y ago
    Couldn't make the PR with the Super Mario theme play on my Macbook. It played only the first two notes than it got stuck there.
moyix 11y ago
Another bit of prior work was Tempest For Eliza [1], which generated patterns on old CRT screens to play music (arbitrary MP3 files!) on nearby AM radios. Edit: And here's another one that transmits data over radio by toggling GPIO pins and the UART on a cheap laser printer: http://www.funtenna.org/ http://www.funtenna.org/ [1] http://www.erikyyy.de/tempest/ http://www.erikyyy.de/tempest/
iconjack 11y ago
One more example, from the 70s: TARGET, a text-mode shootem-up on the SOL-20 had sound effects—just put your transistor radio (every kid had one) near the computer while playing. Took a bit of futzing with the tuner, but there used to be more time in the day.
- kpil 11y ago
  Yes. What happened to time? I tried loading a C64 game from tape - and I could not believe that it took that long when I was a kid.
stephengillie 11y ago
This is the same idea as using an AM radio as an audio tachometer in old cars. You can hear the ignition system hum rise and fall in pitch on the radio as the engine rotation rate changes.
kylixz 11y ago
If I put my ear up to my late 2013 rMBP I can actually hear the tune playing without breaking out my SDR. Cool.
mhei 11y ago
Usenix paper this code mentions in the README, includes presentation video: https://www.usenix.org/node/190937 https://www.usenix.org/node/190937 I'll try to find time to try to transmit some data this way and receive it with my rad1o.
OrangeTux 11y ago
> Instructions in this program cause electromagnetic radiation to emit from the computer. I understand that part. but don't understand the technical details. Could someone elaborate a bit how this works?

499 points by sssilver 11y ago

xlayn 11y ago

I wonder if deployed around the world there is a network of radios sync by GPS to receive time encoded encrypted communications signals of every electrical powered devices configured to transmit according to the same principle and all the things about security are just a curtain behind the capability of capturing everything that has already been deployed. Given that this is CPU and subsystems related doesn't have anything to do with software running... it could be capture and executed by a routine in the CPU out of every possible observance by dedicated circuitry, this would fall under all the requisites mentioned by the poster Be emitted by the computer processor and other subsystems Escape the computer shielding Pass through the air or other obstructions Be accepted by the antenna Be selected by the receiver Neurosis off... Edit: Neurosis on You know what escapes computer shielding? cables... like the ones with cpus that are used for connecting to external devices... Neurosis off.

exDM69 11y ago
I recall seeing a cryptographic side channel attack based on radio frequency interference from the victim computer. I don't have a source for this but I'm sure someone will find a link soon enough.
- mtreis86 11y ago
  I remember this being done with microphones, listening to the clicks of the coils. Related? http://www.cs.tau.ac.il/~tromer/acoustic/ http://www.cs.tau.ac.il/~tromer/acoustic/ Edit, found in one of the links on that page, seems this is the same group http://www.cs.tau.ac.il/~tromer/ecdh/ http://www.cs.tau.ac.il/~tromer/ecdh/
lost_name 11y ago
Is what you're looking to be paranoid about? https://en.wikipedia.org/wiki/Tempest_(codename) https://en.wikipedia.org/wiki/Tempest_(codename)
- j_s 11y ago
  Also https://en.wikipedia.org/wiki/Van_Eck_phreaking https://en.wikipedia.org/wiki/Van_Eck_phreaking
  - Arubis 11y ago
    And thus, it's obligatory that someone recommend Neal Stephenson's _Cryptonomicon_, in which this features quite heavily.
    - ibmthrowaway218 11y ago
      And, within 24 hours or so someone will submit the Van Eck Phreaking Wikipedia page link as a standalone submission on HN.
      - fabulist 11y ago
        As long as we're making tangential recommendations and expecting to be reintroduced to things within 24 hours, I'd like to throw John Dies at the End into the ring.
        raddad 11y ago
        RF leaks are an old tune, NSA was using it back in the 60's I believe. There was an article in Wired about this topic in 2008[0] Gene Hackman and Will Smith in a movie Enemy Of The State (2009)[1] hinted at this technology. [0] http://www.wired.com/2008/04/nsa-releases-se/ http://www.wired.com/2008/04/nsa-releases-se/ [1] http://www.imdb.com/title/tt0120660/?ref_=nm_flmg_act_10 http://www.imdb.com/title/tt0120660/?ref_=nm_flmg_act_10 (edit for formatting)
      - adenner 11y ago
        it was already done ~86 days ago, so it won't be back for a bit longer https://news.ycombinator.com/item?id=10684447 https://news.ycombinator.com/item?id=10684447
      - 11y ago
lallysingh 11y ago
I feel like you've just written half of the script for the next Transformers movie.
WillKirkby 11y ago
There's this DEFCON talk that (among other things) covers how an unshielded display cable can potentially leak screen contents over RF. Well worth a watch if you've got the time. https://www.youtube.com/watch?v=_g9yUiAHiFo https://www.youtube.com/watch?v=_g9yUiAHiFo
ikeboy 11y ago
If this was true, you'd expect hobbyist radio operators to notice, right? That increases the required conspiracy size by orders of magnitudes.
- xlayn 11y ago
  Out of the Neurosis joke area and in line with your hobbyist radio operator comment, probably the person who most know about how to perform radio transmissions using a component by re-purposing them are those who work shielding sensible components away from it. For example power bricks that contains every day more and more circuitry could implement a protocol of communication by de-modulating a message sent by AC and then sending via radio to the computer the message; process that's even easier with power cables with data lines.... like the usb cable.

pierrec 11y ago

"Different results will be achievable with different equipment. Please send your results to sbr@phor.net" I think the barrier to entry for this is raised by the fact that most people don't have AM receivers anymore. If I find one lying around though, I will certainly give this a try. Ah, and apparently this proof-of-concept works exclusively on OSX for now.

croddin 11y ago
Almost all cars still have them, just bring a laptop into a car.
- devy 11y ago
  BMW i3 has the AM hardware builtin but disabled it in firmware [1] due to the exact same reason: electromagnetic interferences caused poor quality of the AM reception. Obviously, AM radio on i3s can be re-enabled by firmware hacking - called "coding". [2] Even with the full metal body/frame, AM radio noise caused by EMI emitted from EV motor/circuits was still significant. I guess it's still VERY HARD to shield these EMIs. Full disclosure: I've owned BMW ActiveE and BMW i3. [1] http://www.greencarreports.com/news/1098893_bmw-i3-electric-car-quirk-no-am-radio--but-why http://www.greencarreports.com/news/1098893_bmw-i3-electric-... [2] http://www.greencarreports.com/news/1099782_bmw-i3-rex-electric-car-coding-unlocks-features-owners-want-and-may-void-warranty http://www.greencarreports.com/news/1099782_bmw-i3-rex-elect...
  - mikeash 11y ago
    The Tesla Model S has AM. It's fun to tune the radio to an unused frequency and drive around. The radio picks up a ton of noise that sort of emulates just a little bit how a loud gasoline engine would sound. I hear that they've removed AM from the Model X.
    - devy 11y ago
      The radio picks up a ton of noise that sort of emulates just a little bit how a loud gasoline engine would sound. It's the same behavior in BMW EVs(i3/i8/ActiveE/MiniE). It's not a constant noise on AM radio but really when you press the accelerator pedal hard on a quiet street could you hear the interference. BMW consider that unacceptable based on their "standards". Apparently a lot ofTesla Model S owners agree with BMW on the subpar AM radio reception and complaint on their forum[1], which was probably why AM radio removed from Model X. I do consider that a surprise feature (of emulating engine revs) albeit it's a bit annoying sometimes. [1] https://forums.teslamotors.com/forum/forums/am-radio-stations-make-whir-sound-car-accellerates-and-slows https://forums.teslamotors.com/forum/forums/am-radio-station...

dwyerm 11y ago

This is probably the wrong reaction to this article, but it is mostly making me nostalgic for the distinctive musical RF interference that comes from a C64 while it is in a FOR delay loop.

amyjess 11y ago
That's not the only part of the C64 you could make music out of. My co-worker told me of a program he downloaded from a BBS back in the day called "Drive Music" that turned his C64's floppy drive heads into a musical instrument.
- threeio 11y ago
  https://www.youtube.com/watch?v=5gnMgmlKi_o https://www.youtube.com/watch?v=5gnMgmlKi_o
  - beamatronic 11y ago
    I had this! It was amazing but IIRC it came with a disclaimer that you may need to re-align your drive heads afterwards.

TerryADavis 11y ago

The longer you fight God, the worse it gets, silly nigger. God says... entourages Regina's doggoning functions adjudicate Getty righteously hoarseness's winterizes czars flyleaf justness's impromptu's collectibles servitude rinse averages sympathize inquest McGowan's grandeur's Richelieu's scooting ostensible boggiest exhibitor rockers nostrils blooms saddle's piddle cavalry

jmount 11y ago

Neat. In the 1970s there was a program that triggered the S100 bus of the time and played Flight of the Bumble Bee on a nearby radio.

dbcurtis 11y ago
Ha Ha! Yes. I was thinking the same thing. My old college roomie had an old 8080 system (Cromemco??? I can't remember.. it was the pre-Apple II days...) and used to run that program and similar radio noise makers. I think there was some space game that used bus noise for weapon effects.
- jmount 11y ago
  Mine was IMSAI 8080. But I had forgotten- I think one of the Star Trek games did the phasers on the radio.

calebm 11y ago

Wow, if this works, that is awesome!

calebm 11y ago

Just tested on a MacBook Pro (Retina, 15-inch, Late 2013) and it didn't work. (Although I see in the README it says to run it on an Apple MacBook Air 13-inch, Early 2015). Anyone else get it to work?

fulldecent 11y ago
Thanks for your feedback. Even different models of the same computer will have different results. But I suspect that the MBPR you have will likely still work. Please check different AM channels and put the antenna directly on the computer to get started. If you find another frequency that works please let me know (email on the project page).
thought_alarm 11y ago
Works for me on an Early 2014 MacBook Air and Mid 2011 iMac, although the iMac signal is very, very weak.
klagermkii 11y ago
Works here on a Retina 15-inch mid-2012 MacBook Pro. You've got to have the antenna real close to the machine (talking 10 cm here), turn the dial pretty much to the end of the AM band and then you can hear the tune through loads of AM static.
calebm 11y ago
UPDATE: This DID work for me on my MacBook Pro (Retina, 13-inch, Late 2013). Nicely done @fulldecent!
whyleyc 11y ago
Works fine on my MacBook Pro Retina, 13-inch, Early 2015. Quite a lot of static, but an amazing moment when you do pick out the tune for the first time !
ultrafez 11y ago
Working on a mid-2012 15" non-retina MBP. I was able to pick up the tune on various frequencies, starting around 650khz and on various other bands right up to around 1500khz (my radio's upper limit).

FreeFull 11y ago

There also used to be a program that would transmit audio over radio waves using a CRT monitor.

FreeFull 11y ago
Here it is: http://www.erikyyy.de/tempest/ http://www.erikyyy.de/tempest/

throwaway21816 11y ago

RIP Airgap

deleted 11y ago

[deleted]

voctor 11y ago
Replacing _mm_stream_si128 with a simple x++ will work too.

corysama 11y ago

Somewhere out there is the story of the guy who brought his Alto computer and electric guitar to the infamous Computer Club. He set the guitar on the computer and the speaker started playing Mary Had A Little Lamb. He had written a program to set and unset registers at specific frequencies.

eliteraspberrie 11y ago
This is how we got sound to play on the TI graphing calculators. It sounded bad and drained the batteries but it was fun. Another fun thing was getting grayscale graphics on those screens. They had only black and white pixels but flipping them on and off at different frequencies made them gray.
stevetrewick 11y ago
According to Steven Levy's 'Hackers'[0] it was Steve Dompier's Altair, it was a radio not a speaker, and the tune was the Beatles' Fool on the Hill. [0] Which it turns out is online at http://www.gutenberg.org/cache/epub/729/pg729.html http://www.gutenberg.org/cache/epub/729/pg729.html
- GFK_of_xmaspast 11y ago
  Question to Radio Yerevan: "Is it correct that Grigori Grigorievich Grigoriev won a luxury car at the All-Union Championship in Moscow?" Radio Yerevan answered: "In principle, yes. But first of all it was not Grigori Grigorievich Grigoriev, but Vassili Vassilievich Vassiliev; second, it was not at the All-Union Championship in Moscow, but at a Collective Farm Sports Festival in Smolensk; third, it was not a car, but a bicycle; and fourth he didn't win it, but rather it was stolen from him."
  - nine_k 11y ago
    (The canonical version says something like "The information is generally correct, but subject to four adjustments".)

jpalomaki 11y ago

What about receiving these communications using computer without special hardware? Could this interfere with audio, wifi or some other component in away that could be detected by software? Quite certainly decent bit rates would be out of question, but would it be possible to pass any information between two computers using this?

mafuyu 11y ago
It would certainly be very difficult. If you could get the bus noise near the 2.4GHz freq range (unlikely), you could use the wifi of the other computer to potentially receive. Another thing people have experimented with is using the speaker/microphone at above human hearing range. This method usually falls flat because crappy laptop speakers have a hard time going above 20kHz. One thing I could potentially see working is a laptop with a hard drive generating vibrations with the motor. Then, a smartphone or laptop with an accelerometer could pick up the signal using the coupling through a table.
- simcop2387 11y ago
  Wifi being so high bandwidth it'd be very difficult. Bluetooth Low Energy supports very small bandwidths and would be significantly easier to generate in the end. You generally don't get good enough control over the motors or voice coil in a hard drive to be able to make vibrations like that. I'd probably look at controlling the fans instead to get a similar effect and use the microphone to listen for the noise from them.
  - mafuyu 11y ago
    I was thinking along the lines of hard drive spin down/spin up due to power state configurations. The fans would probably be easier, though, provided you could pick up on it.
  - 21 11y ago
    There are videos on youtube with people making hard drives "sing" by carefully computed seek actions.

Kinnard 11y ago

Fascinating!!!

y04nn 11y ago

It's what have been done in 1977 on the MITS Altair 8800 by Steve Dompier at the Homebrew Computer Club. The beginning of the personal computer history.

kw71 11y ago
We did this on the zx81 too. I think there was a game that used an AM radio for sound. It was certainly written up in the contemporary computer magazines. I guess this will be rediscovered every time someone happens to figure out timing loops while they have a radio nearby.

hookshot 11y ago

Worked great on my MacBook Air (13-inch, Early 2015) with an old panasonic boombox. Very cool!

ramgorur 11y ago

I am in kind of dark here, where is the antenna? the wires on the system bus? or the copper coil in the speaker? could someone please explain it a little bit more?

jhallenworld 11y ago
It's just leakage. Any high power component which can be controlled by the program is likely to do it. Remember that the radio receiver's gain is essentially infinite- the limit is the noise floor. If there is any leakage above the noise floor, you are going to pick it up. There are lots of related tricks: tune a communications receiver to 455 KHz, and you will pick up the station that a nearby radio is receiving (because it's picking up IF leakage). Also the inverse works: the IF amp is where all the gain is, so if you transmit on 455 KHz, you can jam nearby AM radios no matter what they are tuned to. My dad did this when he was a kid in the 40s with a single tube transmitter.
slug_tro_AWAY 11y ago
Any oscillating electric current transmits magnetic waves of a certain strength. Certain oscillations at particular frequencies represent radio waves. At lower frequencies, one might merely act directly upon the magnetic transducers of a poorly-shielded audio speaker, creating sounds at volumes and within ranges audible to humans. Any segment of electric wire, carrying a current that can change direction, might be used to this effect. Stronger electrical activity over a bigger, better wire has higher chance of sending a signal that can be detected.

hansjorg 11y ago

Very interesting. Reminds me of a similar project from Fabrice Bellard, using a VGA card to broadcast a DVB-T digital television signal: http://bellard.org/dvbt/ http://bellard.org/dvbt/

Swannie 11y ago
Thanks, this was at the edge of my memory, but I was struggling to recall :-) I think Fabrice's demo is much more interesting, as it's significantly denser information.

soheil 11y ago

I did something similar back in the day using CRT monitors that displayed the right image at the right time to produce desired radio waves. The range was very limited, however, and lots of background noise but you could certainly hear the music that was playing if you tuned your radio and brought it real close to the monitor.

kens 11y ago

Generating music via radio interference goes way, way back. The IBM 1401 (1960's era) could do this:https://www.youtube.com/watch?v=EPk8MVEmiTI https://www.youtube.com/watch?v=EPk8MVEmiTI It could also play music on the line printer by banging out the right sequence of characters. http://mail.computerhistory.org/pipermail/1401_software/2009-February/000289.html http://mail.computerhistory.org/pipermail/1401_software/2009... Strangely, the 1401 radio music was later set to orchestra and released as a CD by an Icelandic composer: http://www.npr.org/templates/story/story.php?storyId=7408766 http://www.npr.org/templates/story/story.php?storyId=7408766

RachelF 11y ago
Back in the early 1980's this was the standard way to produce sound on the (Timex) Sinclair ZX80.
semi-extrinsic 11y ago
Old HP scanners used to have a music-making easter egg: http://youtu.be/8JwU5mcIwDw http://youtu.be/8JwU5mcIwDw
alanh 11y ago
In the vein of old hardware playing music, you should absolutely check out this cover of Radiohead’s “Nude,” if this sort of thing interests you. I find it strangely moving. http://alanhogan.com/big-ideas-dont-get-any http://alanhogan.com/big-ideas-dont-get-any (direct link http://www.vimeo.com/1109226?pg=embed&sec=1109226 http://www.vimeo.com/1109226?pg=embed&sec=1109226)

chrischen 11y ago

Can this read other data in the system bus?

peterwwillis 11y ago

Andrews Airforce Base's Emission Security Information Guide https://web.archive.org/web/20011117002220/http://www.andrews.af.mil/89cg/89cs/scbsi/emsecguide.doc https://web.archive.org/web/20011117002220/http://www.andrew...

jventura 11y ago

For those that do not have a Mac or AM radio, I made a small video for you: https://youtu.be/oXAeGZaka7o https://youtu.be/oXAeGZaka7o It's a Macbook Pro late 2013 and a pretty stock FM/AM radio.

JetSpiegel 11y ago
https://www.youtube.com/watch?v=Nroc2BtO6NU https://www.youtube.com/watch?v=Nroc2BtO6NU There's already a PR with Linux support, it works! There's another PR to play the Super Mario theme, that also works.
- kefka 11y ago
  I won't be one of the cool kids and make a video but; Thinkpad T61 works with the Linux branch.
- jventura 11y ago
  Couldn't make the PR with the Super Mario theme play on my Macbook. It played only the first two notes than it got stuck there.

moyix 11y ago

Another bit of prior work was Tempest For Eliza [1], which generated patterns on old CRT screens to play music (arbitrary MP3 files!) on nearby AM radios. Edit: And here's another one that transmits data over radio by toggling GPIO pins and the UART on a cheap laser printer: http://www.funtenna.org/ http://www.funtenna.org/ [1] http://www.erikyyy.de/tempest/ http://www.erikyyy.de/tempest/

iconjack 11y ago

One more example, from the 70s: TARGET, a text-mode shootem-up on the SOL-20 had sound effects—just put your transistor radio (every kid had one) near the computer while playing. Took a bit of futzing with the tuner, but there used to be more time in the day.

kpil 11y ago
Yes. What happened to time? I tried loading a C64 game from tape - and I could not believe that it took that long when I was a kid.

stephengillie 11y ago

This is the same idea as using an AM radio as an audio tachometer in old cars. You can hear the ignition system hum rise and fall in pitch on the radio as the engine rotation rate changes.

kylixz 11y ago

If I put my ear up to my late 2013 rMBP I can actually hear the tune playing without breaking out my SDR. Cool.

mhei 11y ago

Usenix paper this code mentions in the README, includes presentation video: https://www.usenix.org/node/190937 https://www.usenix.org/node/190937 I'll try to find time to try to transmit some data this way and receive it with my rad1o.

OrangeTux 11y ago

> Instructions in this program cause electromagnetic radiation to emit from the computer. I understand that part. but don't understand the technical details. Could someone elaborate a bit how this works?