Generate AM Radio Broadcasts With Your Monitor

tessellation writes: "Tempest for Eliza is a program that uses your computer monitor to send out AM radio signals. You can then hear computer generated music in your radio." Here is your big chance to disrupt free thinking radio programs in your neighborhood.

Comments

Done it...

[Kymermosst]

It really worked... it took more work than the instructions portrayed to get it working, but it's pretty nifty.

Can't do MP3s yet... at least, not the version I tried.

first post?

Re:Done it...

[stonecoldt]

How far away can you hear it?

Re:Done it...

[Kymermosst]

With a crappy radio, it had to be fairly close 5 feet to make it out... my monitor doesn't put out that much rf... it's a low-rad type.

Now, putting my ham radio at 5 watts about 10 feet away does interesting things to my monitor, I can tell you that!

Re:Done it...

[SomeoneGotMyNick]

I remember getting the same crappy performance from a $20 Radio Shack AM Broadcasting kit back in '77.

It figures that I had to wait 25 years to be able to do the same thing with $1000 worth of computer hardware.

Still, I wonder if I can use this technique to calibrate an HF tranceiver.

Re:Done it...

[PCSElectronics]

How about turning your PC into a FM radio transmitter and play some stereo MP3's? But
you'll need a piece of hardware to do this,
its called PC MAX.
Comes in PCI or ISA, its fully controlable
by software as far as frequency and power are
concerned.

Check it out at http://www.pcs-electronics.com

Just thought this is related. I find the idea
with the monitor totally awesome otherwise.

Marko / PCS

weird, its not working

[ddent]

I wonder if it has something to do with how thin my monitor is... now wait a second, does this work on LCDs? :) Oh, maybe thats why...

Re:weird, its not working

[Anonymous Coward]

Ah, but it _is_ working. It's not your monitor that is emitting the signal - it's the cable between your computer and the monitor.
Be afraid, big brother is watching you :-)

Re:weird, its not working

[seann]

maybe its because he has a few to many ferrets.

stream mp3s?

[stonecoldt]

.ogg files would sound so much better out of that AM radio. :-P

Re:stream mp3s?

[metrix007]

lol, mp3's own ogg

Re:stream mp3s?

[chryptic]

Hmm... what does an mp3 look like?

Re:stream mp3s?

[Anonymous Coward]

Better idea--use that crappy internal speaker :)

I was bored enough to make a VBscript (don't ask) program that did this. Found several interesting things. Aside from cheesey muzak (to annoy one's cow orkers by ;) you can play random sounds each for one millisecond. It sounds rather like there's a squeekey wheel in there (or that the HD is melting)

Good thing no VBscript viruses ever added this code (though it works only on NT, BTW, due to changes in the Beep API) or it'd freak out people when it claimed to be deleting their hard drive (while, hopefully, not actually doing that...)

This isn't the first

[recursiv]

This isn't the first time something like this has appeared on slashdot. Way back in the day ('99) there was an article about a guy who was using the radio interference from his motherboard to do the same sort of thing.

Re:This isn't the first

[Tails]

You beat me to it. I submitted the similar article back in '99 and felt a strange sense of deja-vu reading the slashdot headline. Common slashdot, lets try to keep it fresh!

Re:This isn't the first

[quinto2000]

Not everyone has read Slashdot for several years, or reads it religiously each day. I, for one, found this to be something interesting that I learned a little about. Similarly with the steganography articles: it's an old concept, I had heard a little about it, but the Slashdot post for once actually gave me new information. This kind of story is much more "news for nerds, stuff that matters" than an announcement of the next kernel prerelease. If it's a little redundant, it's worth the price.

Re:This isn't the first

[rm-r]

and the older story was about FM radio waves which would be much more useful (in this country anyway) sadly the link has died, anyone know where I might find more stuff on this?

Re:This isn't the first

[laslo2]

I remember reading about using an altair and an am radio to generate music many years ago (in hackers (steven levy)).

still pretty cool... but not 'new'. this has been your cynical moment for today.

Re:This isn't the first

[Lew Pitcher]

Lessee...

Around 1979, Steve Dompier released a short 8080 assembly program for the Imsai 8080 that played music on an AM radio by generating timed/tuned rf inteference (Article in Dr. Dobbs "Music of a Sort")

Around 1975, friends of mine had done the same thing with an IBM minicomputer at their highschool, using rf from disk and printer data transfers to generate music on an AM radio (added bonus, percussion was supplied by the line printer, using selected print data).

No, this is not new.

Re:This isn't the first

[b1t r0t]

Way back in the real "way back in the day", around 1980 or 1981 or so, before the FCC got into the act, I was using the RFI from my TRS-80 to generate music. The cool part was that any code to generate sound out the cassette port was sufficient to have the sound show up on an AM radio via RFI.

Re:This isn't the first

[Monte]

Around 1979, Steve Dompier released a short 8080 assembly program for the Imsai 8080 that played music on an AM radio by generating timed/tuned rf inteference (Article in Dr. Dobbs "Music of a Sort")

"Short" is relative when you're pounding the hex dump into the system RAM via the front-panel switches :)

From this site the basic concept goes back at least to 1975:

"The 4th meeting of the Homebrew Computer Club is held at the Peninsula School in Menlo Park. Steve Dompier plays the music "Fool on the Hill" and "Daisy" using the Altair and a radio."

Re:This isn't the first

[Anonymous Coward]

Come on now. Just because someone doesn't explicitly put ... or other goofy stuff like that in a post doesn't mean we need to turn off our humor radar and get hurt.

Oh wait. Maybe you're being sarcastic too.

Nahhh.

Re:This isn't the first

[number11]

Wasn't new even then. In 1965 or '66 we had an AM radio sitting on top of the console of my school's IBM 1620 (small mainframe), and people were writing programs to play music on it.

But the original author wasn't claiming "new", it was more a way to dramatize the van Eck radiation. And note that the example uses an AM radio tuned to 10MHz (that is, shortwave, not the US 540-1620kHz broadcast band).

Back in ancient times

[ynotds]

This is really testing my memory, but I think it was after we upgraded from our IBM 1440 to an early System/360 that our operators discovered they could tune an AM radio to a certain frequency and thereby listen to the puter.

Maybe somebody with a better memory might know a few more details.

Re:Back in ancient times

[Florian Weimer]

Our local computer museum has got a PDP-8 which can broadcast polyphonic music using its main CPU, running a specially crafted sequences of instructions. Actually, operators used the AM radio effect to monitor the machine activity. With some experience, you can here if the CPU is idle or spinning in some kind of endless loop. If you are familiar with a longer job, you can guess which part is currently running, and estimate the remaining time.

At home, my computer has a similar feature: if the CPU is loaded, the sound of the fans changes, so I can tell if the computing-intense job is still running or not.

Re:Back in ancient times

[Richard Kirk]

I remember listening to HP calculator programs using a shortwave radio. I also remember some PDPs (?) that had a loudspeaker.

An even older technique with ancient valve computers was the 'stop loop'. You put 'A: GOTO A' at the end of your code, which caused the electronics to whistle, to tell you your data was ready. Not so good for multiuser systems, though.

Aaarrr, those were the days, when you programmed with a 60W soldering iron and a pair of tinsnips. Kids today think clicking a mouse is programming, don't know they've been born, blah blah etc....

Re:Back in ancient times

[nafmo]

In more recent times, my Commodore 128 tended to jam one of the local FM commercial stations back where I used to live (only in my room, though).

Considering we only had two commercial radio stations in the area, and the other one was crap, this was a disappoitment.

Re:Back in ancient times

[dohnut]

At home, my computer has a similar feature: if the CPU is loaded, the sound of the fans changes, so I can tell if the computing-intense job is still running or not.

Heh, same here.. I can tell when my website gets hits (which isn't very often) by listening to the fan's tone.. I keep wanting to remove that fan (it's not necessary to have in that chassis), but I'd have to disconnect power and it's got an uptime of 412 days. :)

Re:Back in ancient times

[chubso]

Dr. Dobbs (Journal of Calesthetics and Orthodontia) had an article for playing tones from an 8080 machine using memory accesses to generate the pulses. I got it to do 3 voice harmonies over an AM radio. I also used the radio to tell me if my assembly was going OK or if I had a coding error. The sound was completely different and at times I could even guess about where in the code the error occurred. Man we had way too much free time back then!

Re:Back in ancient times

[GigsVT]

You can hot swap fans, it's really not dangerous. Unless it's your CPU fan. :)

Re:Back in ancient times

[Anonymous Coward]

Yes. There was a kid doing this at the Caltech computer center on the PDP-10 back around 1971.

Re:Back in ancient times

[Anonymous Coward]

I saw this done in the mid 1970's on a system/360.
An AM radio was placed in the CPU cabinet.
It was common to do that as a way to monitor the
computer. certain jobs would make the same sounds
every time. If not something was wrong. Then
someone figured out how to play music.

Later the OS got more complex and would multi-
task many jobs so the radio was not usfull.
But now we have PCs that are more like 1960s
computers (one cumputer per task) so we can
play AM music again.

They were also able to use the line printer
to play some crude songs too

Re:Back in ancient times

[Anonymous Coward]

I have some object decks stashed (anyone 'member 5081 cards?) for IBM S/360s that will play specific monotonic songs (Jingle Bells, etc). Thought I was a fool to hang on to nostalgic rubbish...

this reminds me...

[anotherone]

This reminds me of a game I used to have for my TI-82. As I recall it was a dumb game, but it was the first (and as far as I know, the only) calculator game with music.

I think it worked by twiggling the link port's connection really fast or something, but if you held it near an untuned radio, it'd play really poor music. Really, really bad music. But, hey; what do you expect from a damn calculator?

Anyway, this is one of those completly useless, yet incredibly cool things that I like to see. Very neat.

Re:this reminds me...

[10e 999]

Actually, the TI's motorola processor has a few sound instructions that produces (I believe) 2 bit sound. This was on a TI-85, but I've never seen it used before.

Re:this reminds me...

[FuegoFuerte]

Actually, quite a few of the games for the TI-86 have music. Mario does, and I believe Tetris does also. (at least the versions I had). I've since gone to the TI-92+, and haven't tried it with that. On the 86, I heard rumors that you could tune it with an AM radio, but you could also plug headphones straight into the data port (with an adapter to go from the 2mm to the 3mm plug) and hear the sound great. Someone actually wrote a program to play music that way, though you can't fit much music into the memory on the 86. Pretty crappy quality too. You can probably still find the programs and info on ticalc.org or somewhere. It's been a couple years, so I don't remember where I first found out about it.

Re:this reminds me...

[ameoba]

but there's no speaker in the machine, so what good is it?

or are you saying that the CPU has radio tranmission opcodes? Something says the FCC would look poorly on that.

Re:this reminds me...

[WorldSpawn]

>but there's no speaker in the machine, so what
>good is it?

Well, there's no speaker, but with an adapter you can plugin some headphones. I tried this, but I never got it to work very well. There were some programs that supported it though.

Re:this reminds me...

[Barbarian]

Back when the Hp-48G or GX was new, there were lots of games released with music...

Re:this reminds me...

[Tassach]

IIRC, the "headphone" jack on the TI-8x series calculator is actually a serial port, so that programs can be transferred from one calculator to another.

Re:this reminds me...

[Anonymous Coward]

yes, it was a serial port, there was an adaptor you could buy that hooked into the serial port on your computer to transfer programs to/from your computer (you could also make your own parallel port version, I made one of those myself). The coolest thing I ever did with that was to make a radio transmitter... only had like a 1 ft range, but eh, it was still cool.

Re:this reminds me...

[kvx]

Actually the first game to use sound (AFAIK) was zpong on the TI-85. TI calculators generate sound by plugging a speaker into the link port, or an earphone if you prefer. This is unlike the HP calculators which have a built in speaker.

Re:this reminds me...

[drewbradford]

Rumor has it that you can just hook a piezo buzzer to the data port.

Weird.

[MasterOfDisaster]

This could be one of the stranger uses of standard hardware I've ever seen. Would it be possible to make signals more fun then just beeps? Cause, beeps are cool...but, brodcasting audio at a higher quality would be very cool. I mean, hell, we all have some spare CRTs laying around...it could be your own personal radio station! no need for a stinkin transmitter...you can just use your screen.
I shudder at what people will come up with next...

Re:Weird.

[Kymermosst]

I shudder at what people will come up with next...

One day, I'll make a car powered by stupidity

I think your .sig coming true would make me shudder. :)

Re:Weird.

[Andux]

it could be your own personal radio station

Great. We could piss off the RIAA and the FCC, all at once.

Seriously, though, I doubt you could get a strong enough signal out of it for a decent broadcast (and if you can, you're probably glowing in the dark already). You'd be better off just bolting a big chunk of metal to the roof and doing things the old-fashioned way.

Re:Weird.

[bonzoesc]

You haven't seen "The Fast and the Furious" have you? Awful movie that brought ricer culture to North America.

Re:Weird.

[hawk]

>> I shudder at what people will come up with next...

> One day, I'll make a car powered by stupidity

yeah, but think of how fast it would be . . .

hawk

Re:Weird.

[Happy Monkey]

Could you extract the stupidity and take it with you (in a shielded container)? Or would you have to take the stupid person with you in the car?

Eliza?

[the Atomic Rabbit]

Huh? Does the program use your monitor to produce a radio program about psychotherapy? How do you describe your problems to it?

Re:Eliza?

[x136]

]Hello Eliza.
Hello.
]I don't feel very good.
Why is it that you don't feel very good?
]Well, my monitor is talking to my radio.
Are you concerned about your monitor talking to your radio?
]Well, yes. It's not supposed to work that way.
Why isn't it supposed to work that way?
]Shut up Eliza.
Why do you want me to shut up?
]Because you are a stupid worthless computer program.
I sense much anger in you. Perhaps you should seek medical help.
]Oh, what do you know?
What is it about what I know that interests you?
]ARRRRRRGGGHHH!!!
I don't understand what you mean by ARRRRRRGGGHHH!!!. Please try again.
]quit
OK. Goodbye.
]

Re:Eliza?

[poot_rootbeer]

> Huh?

Can you elaborate on that?

> Does the program use your monitor to produce a
> radio program about psychotherapy?

Why do you say that?

> How do you describe your problems to it?

Is it because do me describe my problems to it that you came to me?

-Dr. Eliza Sbaitso

Re:Eliza?

[Anonymous Coward]

] What are you doing, Dave?
just installing a new program...
] I can feel that, Dave...

Van Eck phreaking

[jasonzzz]

For many years during the cold war, the NSA had
been nervous about natural radiations emanating/broadcasted by VDTs and electrical wiring. So much so that many government sites were constructed with TEMPEST safeguards with thick concrete walls, wiremesh shielding and isolated electrical works. Even then, VDTs, type writers, phones, and other electrical devices were never placed close to walls adjacent to the outside of the enclosed space.

Read the Van Eck document.
http://www.shmoo.com/tempest/emr.pdf

Read the TEMPEST page
http://www.eskimo.com/~joelm/tempest.html

Re:Van Eck phreaking

[Ella the Cat]

I typed "van Eck LCD" into Google. From what little I read, monitors using LCDs radiate less than monitors using CRTs as I'd expected. Then again, everything radiates so if you're that worried about security your chances of building a quiet box are minimal. I suppose it's mechanically easier to shield an LCD and it won't overheat as much as a CRT (air vents leak radiation).

Re:Van Eck phreaking

[Incongruity]

I suppose it's mechanically easier to shield an LCD and it won't overheat as much as a CRT (air vents leak radiation).

Actually, you can built shielding in the form of a Faraday Cage, which need be nothing more than a metal screen or a sheet of metal...indeed, a screen like material will work just fine, so long as the open spaces aren't more than about a wavelength (or the minimum wavelength you're hoping to block) in any of their dimensions. If you don't believe me, grab a college (or even a high school) physics book...or see an online resource such as physlink.com

Re:Van Eck phreaking

[elem]

In Neal Stephenson's book Cryptonomicon he talks about Van Eck phreaking against a laptop. As I remember in the book it was done not by leakage from a graphics card (such as one for you video out) but leakage from video-ram since all the different chips in any computer will leak at different frequencies depending on their speed.

Re:Van Eck phreaking

[Anonymous Coward]

The 8-bit Amstrad CPC computers came with their own cheap monitors, which apparently were not shielded too well. I remember tuning a TV in a neighbouring room, and to my surprise finding that you could get an almost readable rendition of the computer screen via a rabbit's ear antenna. So, at least on video frequencies I didn't need any special equipment to spy on my little brother playing games... sadly, we didn't have anything really secret on the computer back then :)

Re:Van Eck phreaking

[Anonymous Coward]

one of my lecturers was in the cia , and he told us a story about how one day they busted this dude for something (not using tempest) , and when searching his room they found a makeshift faraday cage encaseing the entire room.
he wasnt to bright because the survalence guys told him that he always worked with the door to his room open , presumably because he was paranoid about people comeing into the room....
dumb crims

Re:Van Eck phreaking

[SimCash]

I myself had converted an old shielded room (used in testing electronics) into a Tempest-safe computing center at the Air Force Institute of Technology. We had to file all sorts of paper-work, have tests run, etc., then were able to install a couple of old systems (well, they seem old now) including an Ultrix32 system that we used to run force mix studies on using classified data.

And I remember the spooks coming in and telling us they could read our old desktop terminals (not in that room) from a pretty good distance "see that van parked waaaaaaaaaay over there? Boo!".

So, to generate a stronger broadcast...

[Anonymous Coward]

you will need a Beowulf cluster of monitors.

legality?

[rootofevil]

Doesnt every piece of electronic equiptment i own have that little FCC sticker that says it must accept any undesired interference, but not cause any of its own? wouldnt this fall under that exact category?

Re:legality?

[ocelotbob]

This is perfectly legal. All electronic equipment is spec'ed to a certain amount of interference it can radiate. What this hack is working on is the fact that a monitor should be sending out a pretty fixed frequency that can be picked up by an AM radio, similar to how you can hear a repetitive beeping sound if you hold a remote next to an AM receiver in just the right spot. The FCC doesn't care because unless you do some heavy tweaking to your monitor, this isn't going to affect more than the 10-15 foot radius a monitor would normally slightly affect. You're allowed to microbroadcast that amount of distance.

Re:legality?

[Anonymous Coward]

No. 'Cause in this case it's desired interference. :-)

Re:legality?

[Anonymous Coward]

Lets see your equipment "accept any undesired interference" from my 2.3 Farad EMP device... I know mine certianly isn't FCC compliant.

Does that mean if your equipment causes a fire because of my interference, it's not FCC compliant?

this is amazing

[seann]

enough said.
try it out.
this is what they should teach kids in school.

kernel?

[ameoba]

Considering that the 2.5 kernel development cycle hasn't begun yet, is there still time to get the Monitro Sound device driver put in?

Re:kernel?

[Anonymous Coward]

What planet are you from? It started last thursday.

Re:kernel?

[mindriot]

You might just want to write a sound driver for ALSA... they're about to begin pushing ALSA into 2.5...

Next thing ya know...

[WyldOne]

Someone will use an optical mouse as a laser radar jammer.

subliminal messages

[elizard2k]

This is your chance to send out the many subliminal messages to the poor listeners at your work/neighborhood. *snicker*

*crackle* this program has been interrupted by your next door geek .. buy him computer parts *crackle*

Re:subliminal messages

[Anonymous Coward]

Does this mean the whole frigging neighbourhood will know when I'm viewing pr0n?

Ok, how much copper do I have to get...

[Maxlor]

Ok, how much copper do I have to buy to stop it? I have to admit that it's freaking me out a bit how easy it is to pickup the screen's radiation after all, and to make sense of it.

Hm and now I know why PGP lists that "secure viewer" as Tempest-resistant too....

Re:Ok, how much copper do I have to get...

[Aaaaaargh!]

Ok, how much copper do I have to buy to stop it? I have to admit that it's freaking me out a bit how easy it is to pickup the screen's radiation after all, and to make sense of it.

Next time you're remodeling your computer room, just put thin copper plate in the walls, ceiling, floor and door. Weld em' together directly, or with copper mesh and buy a few isolation transformers for your power taps. For good measure, never leave the room, or the three letter acronym brigade may sneak in and install a keylogger without your knowledge. Alternatively, get a bunch of old, "not for residential use" 21-inch monitors, remove any pesky metal shielding and build a jammer with a spare box...

My ancient Nokia does a pretty good job on FM reception, I'd hate to see what this program and removing the shielding could do! :)

Re:Ok, how much copper do I have to get...

[GigsVT]

Wrap your whole house in a fine, RF grounded, metal screen. Don't forget the roof!

for the lazy

[swagr]

Put an AM tuner near your box, and you'll easily find a frequency (many in fact) that let you hear your PC.

Type some keys... move your mouse, open a window...

Not only are you broadcasting... you're composing...

Re:for the lazy

[x136]

Or just hook up some headphones to the built-in audio on the motherboard. Turn up the volume. Tada! Annoying noises.

Re:for the lazy

[Ebon Praetor]

Now that you've composed music, go and copyright it. Then you can say to your friends, 'You can't use that combo of moves in Half Life, I've copyrighted the monitor signals of reloading a weapon.'

Anyone else who opens or closes some windows must pay me royalties...bwahahahahaha...

Re:for the lazy

[SuzanneA]

And put an FM tuner next to it, tune to 100.0 and you should find an empty channel that the receiver claims it is locked to... Assuming you have a 100Mhz clock (or at least a combination of signals that beat to 100Mhz - a 133Mhz FSB + 33Mhz PCI should still produce around a 100Mhz beat freq.) somewhere in your system, that is acting as an unmodulated carrier.

Re:for the lazy

[Bones3D_mac]

An interesting thought here... could this be used to bug someone's hardware and monitor their activity? (Perhaps as a keylogger)

Maybe I should consider putting my system inside a faraday cage. ;-)

Re:for the lazy

[bsdbigot]

Surely, someone has already copyrighted all the possible combinations of mouse-movements, clicks, and key sequences such that anything you hear on the radio would subsequently be subject to a licensing fee ;)

Re:for the lazy

[default luser]

Not a chance. The minimum antenna length for a standard dipole antenna is wavelength / 2

The wavelength for a 100MHz bus is

1 / 100E6 * 3E8 m/s = 3 meters.

YOU are not likely even TWO meters tall. Now, you tell me theres a trace on your motherboard running at 100MHz thats long enough to act as an antenna.

Re:for the lazy

[SuzanneA]

You're falling into the trap of assuming that an antennae HAS to be a perfect antennae, ie, the maximum efficiency. That is all that matching wavelength will gain you. I wasn't talking about broadcasting the 100Mhz carrier 'miles', just enough to affect a FM receiver sat next to a PC.

Anyway, my FM receiver certainly locks to a phantom station at 100.0 when my PC is turned on (and it does NOT when the PC is turned off)

Btw, if you apply the same logic to AM, as in the story these comments are attached to, then you'd have to be arguing that a monitor cannot possibly generate AM freq range signals, because it would require HUNDREDS of meters of antennae.

As to the length of traces on a board, you'd be amazed as to just how long some of them can be, if you were to 'unwind' them.

A better way to tell the eavesdropping feds...

[i22y]

"All your base are belong to us!"

FWIW

[adolf]

While the instructions say to use a shortwave radio tuned to 10MHz, I found that a regular broadcast-band AM radio worked fine. Just chop a zero off of the frequency, and tune in somewhere around 1000. (1030 was what my tuner said, at the point where the "music" was most plainly heard).

Spooky stuff, this.

Re:FWIW

[big_hairy_mama]

Awesome! It doesn't sound as good this way as the tempest.mp3 did (not that that sounded "good" either), but this is the coolest thing that has ever come out of /. :)!

Re:FWIW

[rnd()]

at 1000 KHz you are listening to a harmonic of the 10MHz frequency. Same signal, less amplitude.

Re:FWIW

[Anonymous Coward]

A harmonic is a multiple of a fundamental frequency. Last time I checked 1 was not a multiple of 10, and there was no such thing as a negative harmonic (let's not get into IF frequencies, because that's quite a different thing).

1000 KHz = 1 MHz
10000 KHz = 10 MHz

A proper example of a harmonic would be listening to an AM station on 800 KHz on it's 3rd harmonic of 2400 KHz. Some people make a hobby of listening to mediumwave stations on harmonics that fall into the shortwave bands. This way one can hear rare stations they wouldn't ordinarily hear on mediumwave. This happens a lot with Central and South American mediumwave stations that tend to use transmitters with poor harmonic suppression.

Re:FWIW

[rnd()]

you are correct. since 1000KHz is 1/10 of 10MHz, then 10MHz must not be the fundamental frequency of the 'music' generated. Perhaps the monitor also produces some energy at 1MHz. It would be interesting to compare the 'music' at 1MHz and 10MHz.

Oh geez

[doormat]

How long before the RIAA comes in and tries to force owners of CRTs to stop rebroadcasting copyrighted material. =^/

Re:A Condensed History of the Penis Bird

[ameoba]

Aye...

I'd almost suggest opening up a slashdot section for trolls, but it'd defeat the purpose.

Wireless LAN

[cra]

So, basically, by hooking up some old AM radios ("slightly" modified, of course) to every computer in my home, and by installing some sofisticated software (Will I need a "slightly" upgraded version of the mentioned software, I wonder?), I can actually have a wireless LAN in my home, right?

Re:Wireless LAN

[jfisherwa]

This would be an interesting project. What if you had an AM (is there such? I know of FM) tuner card, captured it, and rebuilt bits out of the modulation?

Re:Wireless LAN

[Anonymous Coward]

Perhaps a device with a built in VGA adapter and
an EEPROM with the drivers and next to that a
digital AM reciever, next to that a USB plug.
Some fancy error correction, network drivers, usb
drivers, a spare monitor, and you'll have a
freenet node.

EvilDrN

What?

[shaunak]

"Here is your big chance to disrupt free thinking radio programs in your neighborhood."

Yeah right Chris, do that on your 400 inch monitor that gives out enough EM emission to cause spontaneous electron-positron pairs to be created in your neighbourhood.

Re:What?

[Stonehead]

What the heck are "free thinking" radio programs? It sounds like I should be happy that I don't know about it.

Laptops?

[krokodil]

This is first time I am sorry I have a laptop!

Nice, but we can do better.

[stuffman64]

Wow, this is really a cool concept, but it is not without its faults. First off, this program only works in short-wave AM, not the regular AM that we all have on our radios. The documentation states a default frequency of 10E7Hz (10MHz), and I doubt that you can get it to work at regular AM frequencies (.53 to 1.7Mhz). A darn shame considering my stereo is literally 1 foot away from my computer...

Secondly, your audio options are limited. Although I have yet to try the program, I'm sure what you get is a MIDI-esque playback of Beethoven's "Song for Eliza" (a.k.a. Fur Elise) at best. Likely, it is just sine-wave beeps at the right frequency. The next step is to figure out how to play .wav files, and the holy grail, mp3 and Ogg Vorbis. I'm sure someone will figure out how to do this in the near future, although I could not imagine good audio fidelity from this method. No worries though, it is not like you bought your monitor to play music. The concept, however, is one of the best I have seen in recent memory. Just don't go modifying your monitor to be a local radio broadcast station, I'm sure the FCC would not like that!

Re:Nice, but we can do better.

[buckeyeguy]

Years ago, I met some guy who claimed that he had hacked his neighbor's stereo by creating a transmitter that went out at the frequency of the stereo's intermediate amplifier, many of which run at about 14.xxx Mhz. He did this to get the neighbor to turn the darn thing down (college kids and their music, ya know). Not sure if the pixel rates could be tweaked to do the same, but there may be some such option that'd work.

Re:Nice, but we can do better.

[3.1415926535]

Likely, it is just sine-wave beeps at the right frequency. The next step is to figure out how to play .wav files, and the holy grail, mp3 and Ogg Vorbis.

Actually, it looks like they're just square-wave beeps to me. It should be pretty easy to play .wav files. All you'd need to do is set an 8-bit greyscale palette and actually generate sine waves. From there playing mp3 and Vorbis files is easy. Just dump the output of mpg123 or ogg123 into the new program. Unfortunately, the electron gun turns off during retraces so there will be tiny chunks of the audio that drop out, but that shouldn't be much more than a low hum. The only problem I can see is that the processor might not be fast enough to push that much data to the screen every vertical refresh.

Privacy Issues?

[MikeyLikesIt!]

From the Tempest page, it seems like you could potentially do the opposite of what this guy is doing - that is, you could tell what is being displayed on someone's monitor by picking up the AM signals from it and reconstructing it on your own display.

So much for all the concern about people picking up your 802.11 traffic! Soon you'll be seeing people driving around with high gain AM antennas, snooping for whatever company memo is on your screen!

Re:Privacy Issues?

[Graymalkin]

that's called van Eck phreaking and has been around for a while now. With a sophisticated enough antenna array you can get basically a screen dump from someone's CRT monitor. With even better equipment and the right processing you can monitor closed circuit signals just by listening to the EMR they give off when current in run through them. Radioshack has the parts to build a toy that can tap a telephone line without splicing wire or having access to cables or trunks.

Re:Privacy Issues?

[Phork]

they will need very large cards to have "high gain" am antennas on them.

Can this be used for transmitting voice?

[dhanav]

Code a picture that will produce a voice and we have an encrypted speech. Sounds interesting. I am going to display all those pics in my collection and listen for hidden messages :).

Re:Can this be used for transmitting voice?

[liquidsin]

sweet
with the proper tweaking, you can get your pr0n to talk to you...

I think I need to try this out with drempels too (win only)

Re:Can this be used for transmitting voice?

[Anonymous Coward]

Aphex Twin ran his self-portrait into a spectrum analyzer and then outputed the audio wave form of it as track 2 of his Windowlicker single, named DeltaMi-1=aSigman=1Di(n)(SigmajEC(i)Fij(n-1)+Fexti (n-1))

Re:Can this be used for transmitting voice?

[dimitri_k]

Not even close. I'm sure it can't generate shorter tones than the inverse of the refresh rate of your monitor. It needs 4Khz for telephone quality voice.

You could certainly get closer to reproducing sampled sound than the song format used by the program. The frequency cap (highest note) is 3.52Khz, but this is based on the highest note that he'll parse, not on the limitations of the program or monitor. I have no idea whether you could tweak the code to provide for volume control, which would give you more than two bits of information per sample, but it doesn't seem wild to believe you could.

Still, with no way to get sub-sub-refresh resolution playback, the most you can hope for is a chord.

Huh?

[MikeyLikesIt!]

What does Art Bell have to do with any of this?

I don't listen to his show - am I missing some sort of inside joke here?

Re:Huh?

[ocelotbob]

chrisd is just making a swipe at the "unusual" topics frequently discussed on Art's program. He's just saying that using an AM radio to listen to a rendition of fur Elise performed by a CRT is more fascinating than listening to Art Bell.

Re:Huh?

[MadAhab]

Well, that was obtuse. I thought he was implying that both things make you want to wear a tin foil hat

Dupe?

[Majik]

Although nothing is coming up, I could swear we've seen this story on slashdot before. Really...
This is old hat, and I coulda sworn it's been covered here before.

Nice demonstration...

[pen]

This is a nice little demonstration that could be used to show people just how easy it is to monitor someone else's computer usage. Anyone out there working for a company that sells Faraday cages? :)

And since we're on the topic of Tempest, does anyone know how well PGP's "Tempest-proof" Secure Viewer works?

Subliminal Channel

[ultrasound]

Another subliminal channel for those FBI Trojans.

I wonder how much information you could leak out without the user noticing - bandwidth for a few passwords and CC numbers is not much.

The Fabulous Altair Connection

[foqn1bo]

I recall hearing something once about the homebrew computer club @ Cal back in the 70's doing something like this using an Altair and a radio to play The Beatles' classic, "Fool on the Hill". It was judged the most interesting and useful thing anyone had managed to do with an Altair yet. I am glad that over 20 years later programmers are dedicated to making our computers just as useful and practical.

Re:The Fabulous Altair Connection

[cthugha]

IIRC, the first time this modulated RF interference was used to create music utilized the services of a PDP-7. (Was there such a machine? It was a PDP-something, at any rate.) There was a demonstration using an Altair at a homebrew meeting, although I think it played something like "Greensleeves". Definitely not The Beatles, tho'.

BTW, if you want to find out about probably the first ever attempt to make music with a computer (although it didn't utilize this technique), check out the music of CSIRAC.

Re:The Fabulous Altair Connection

[Anonymous Coward]

There was a very, very similar application for the sinclair ZX81 too, wayback when. Sold in the U.S as the timex, ISTR,

Re:The Fabulous Altair Connection

[EggWitches]

There's a Robert Cringely Geek History video out there that discusses the Altair. They had no real use for the contraption, and some inventive geek sat down in front of it at a convention for an hour or so reading a list of switches to flip and the order to flip them in off a piece of paper. Halfway through someone kicked the plug out by mistake...and he restarted. At the end, when he'd finally flipped all the switches he needed to flip, he put an AM radio on top of the Altair, and hit run. The radio picked up a tinny version of "Fool on the Hill"
They were so impressed he got a standing ovation and a "Stripped Philips Screw" Award.

Re:The Fabulous Altair Connection

[Mike Schiraldi]

I recall hearing something once about the homebrew computer club @ Cal back in the 70's doing something like this using an Altair and a radio to play The Beatles' classic, "Fool on the Hill".

And if they did it today, they'd get sued by the RIAA. :)

Re:The Fabulous Altair Connection

[darkonc]

There was a similar program for the Radio Shack Model I. It worked using basic Language loops called as subroutines (GOSUB statement). Each loop was slightly different, producing a different tone on the radio.. The loop count variable determined how long the loop ran for. It was called a jukebox because there was a whole menu of tunes you could play with it.

listen to the monitor

[dragonfly28]

This really puts a nice perspective into Eckhart phreaking. All the stories of radiation comming from your can be 'caught' and the info of your screen then been dubbed onto another screen.

Just tune in the radio !

Re:listen to the monitor

[GigsVT]

Van Eck

Re:listen to the monitor

[dragonfly28]

oops sorry 'bout that

Why it's called Eliza

[dido]

Well, it didn't immediately click because the Beethoven song he used to test the program is better known by its German name: "Für Elise" (well, that's what the book of piano pieces I used to have calls that tune). Trouble is, everyone's associations to the name 'Eliza' is the 'AI' program by Joseph Weizenbaum...

It really works!

[ebbomega]

I put my TI-82 up to the stereo and heard Destiny's Child!

(Okay. Bad joke. Couldn't resist... Mod me down as deemed necessary...)

tempest.mp3

[Anonymous Coward]

What's the song in the mp3 given at the site? (tempest.mp3)

Surprised this hasn't been done ad naseum yet...

[ebbomega]

Hopefully, with any luck, a plethora of pirate radio programs will spawn out of this and we'll eventually do to radio waves exactly what Napster did to music.... Pump Up The Volume style...

Honestly, I'd really love to see stuff like that. Total anarchy raged on the airwaves... It'd definately kick the crap out of CRTC (FCC down there I suppose) and we could once again be given the option of Free Press...

I personally will spearhead a Happy Harry Hardon campaign... Who's with me?

interference question

[theluckman]

Would this interfere with the AM broadcast I have coming from my braces? I'd hate to alienate all of my listeners.

WTF is wrong with artbell?

[Anonymous Coward]

He's not exactly an FCC frontman, I think you're just an idiot.

All your funny are belong to six months ago!

[ebbomega]

Someone set up us the dead horse!

Tempest Background Info

[thesolo]

You can find a good source of Tempest Info here: http://www.sans.org/infosecFAQ/encryption/TEMPEST. htm

I find it very funny that this information used to be classified in the 1950's.

Geek history

[pacc]

It all began somewhere in California when a student didn't think that pulling a few switches to get a few red lamps to produce the answer was good enough.

With a bit of experimentation he produced a program that did nothing, but when he tuned in the radio next to the old monster a small tune was heard when his program was run.

Other Examples: One of the highlights of our open day display was a music program running on the DS300. This machine has no loudspeaker - the four-part harmonies are picked up by an AM radio tuned to the rf interference generated by the core driver circuits. For best results, pull your PDP-8 processor cabinet right out and place the radio immediately above the core stack.
Resurrection, some kind of antique computer society

Can't find the correct reference, try yourself to search the net for computer, music etc

Re:Weird. (OT)

[ThatComputerGuy]

Err.. that movie did noo bring ricer culture here... rice rockets have been around for many years, unfortunately...

The movie just highlighted how horribly pathetic most of them are. Granted, there are some that are worthy of being called sports cars, but a stock Civic w/ 5 inch exhaust tip and 2 foot spoiler... hell, that stuff's only going to weigh it down.

Read about this kind of thing once.

[ebbomega]

F2F by Philip Finch. Some hacker posts on a BBS about how we now lack any type of privacy or safety from those who are smart enough to invade peoples' lives...

Well, he attempts to then crack every computer of the people who respond to his post and proceeds to hunt each and every one down. Well, one of them, a hacker/phreaker from the 70s, had designed this device that essentially does just what you proposed here... he tracks down where this bad-guy killer person and checks out the guy's monitor from the broadcasted AM signals. Essentially giving him a unidirectional trojan.

Excellent read. I highly recommend it for anybody who likes Cyber-thrillers. And anybody who likes action-driven novels (Also check out Paradise Junction by the same author).

Only Radio?

[AtrN]

I programmed an Imlac and used to get audible sound out of the monitor when my lines got redrawn too fast. I always thought it was going to blow up.

Re:Only Radio?

[Elvis Maximus]

I recall hearing tales in the 80s of a trojan that would cycle the horizontal and/or vertical hold so fast that some cheapo monitors would actually explode. Not sure if there was any truth to it or not.

Re:Only Radio?

[JimPooley]

There was a POKE for a particular model of Commodore PET which would kill the monitor.
Can't remember what it was, but I'm sure someone out there will...!

Re:Only Radio?

[jacklf]

Since you brought it up... [from the CBM-PET FAQ]:

WHAT IS THE 'KILLER POKE' AND SHOULD I WORRY ABOUT IT?

This is THE POKE of computer lore, the command that WILL physically break a
computer! Of course other commands and methods are known that can
potentially cause damage (usually to disks, hard drives or other mechanical
units), but this is the most notable mainly because it was a command somewhat
commonly used and it affects solid-state circuitry.

History of 'the killer poke'
When the first PETs (small 9" screen) models came out, the display wasnt all
that fast.

The old PETs were slow because the print character ROM routine
waited for the interval between screen scans before updating the screen
memory. This reduced conflicts over the screen RAM which would have resulted
in random pixels (snow) being illuminated on the screen. There was an input
on one of the I/O chips which was hooked up to the video circuitry and told
the routine when to access the video RAM.

It wasn't too long before someone learned they could impove the
character display speed via a poke to location 59458; which would set the
video controller to update more readily. It was a noticible improvement of
speed on programs using PRINT often, it was kind of like a free upgrade.
It was mentioned in a few publications and used in many programs that relied
on printing to the screen. I had learned of the poke through Cursor Magazine,
a monthly tape-based publication. They printed the command in one of the
'newsletter' flyers included with an issue which you could insert into their
game "joust" to make it play faster.

Later on, when Commodore released the larger display (14") PETs, they had
improved the display controller which made that POKE unnecessary. An
unfortunate side effect was that the POKE to 59458 affected a different
register which adjusts one of the newer screen display capabilities, which
could result in damaging the PETs video curcuitry when left running. I
discovered it by accident after our school received some large-screen 4016s.
When active, the screen starts to warp after about the third line and the
display stops around the fifth, the keyboard is also unresponsive. When a PET
is in this mode, the only solution is to turn it off, FAST! Fortunately none
of the school's PETs were damaged due to this POKE. Later Cursor Magazine
published a 'fix' that would allow older PETs to use the poke and keep the
large-screen units from frying. Unfortunately there are still many programs
that do not have this fix.

Cool!

[david_e_v]

This makes me think of Cryptonomicon's Van Eck phreacking references as something more than fiction.

range

[Ignimbrite]

I got this to run with little difficulty.

Using my FT-817 with its 6m/50MHz antenna, Eliza at 50 MHz could be heard at least 15 feet from the side and front of my monitor. I would try the range in other directions, but I don't have room!

I was wondering why amateur radio reception was so poor in the dorm, and now I know why.

Re:range

[Anonymous Coward]

FT-817.. nice QRP rig.

I've been torn between one of those and an Elecraft K2.

Hamming from the dorm is difficult but not impossible. Of course the greatest difficulty is getting an effective enough antenna up.

I'd suggest you try to track down an AEA Isoloop. Small enough to fit in the dorm and quite effective, so I've heard. If you can somehow hang it out the window, even better.

Re:range

[Anonymous Coward]

S/FT-817/FT-100D and see what happens when you key it up! It's one way to meet your neighbors, up close and personal. And, 6m will do nicely, particularly if they're trying to watch Ch.2 on the TV. If not, well, you could always go down to 160 and see if Eliza can cope with some competition. (Been there, done that, 30 years ago with an SB100 on 15m - amazing what happens when you mix strong RF fields with speakers and their wiring in a 4-story college dorm building! :-)

Re:range

[Anonymous Coward]

...feet from the side and front of my monitor. I would try the range in other directions, but I don't have room!

Amateur might be the key word here.... Ever considered turning the monitor around with the back end pointing to your face? This should make it possible to measure the radiation in that direction, no?

Re:Surprised this hasn't been done ad naseum yet..

[sheol]

Unfortunately, the signal coming from your CRT is pretty weak. I had trouble picking it up on a radio more than a few feet away.

what about a beowulf?

[Barbarian]

Seriously, though, I doubt you could get a strong enough signal out of it for a decent broadcast (and if you can, you're probably glowing in the dark already). You'd be better off just bolting a big chunk of metal to the roof and doing things the old-fashioned way.

Imagine a beowulf of these, though...

Legal issues

[Pat__]

I don't know the range of this thing :)
But correct me if I am wrong ... Isn't it illegal to broadcast on AM frequencies without a licence in most parts of the world?

Re:Legal issues

[rob_horton]

I guess it's only at a level which the monitor would be giving off anyway (the monitor presumably complies with the FCC regulations), just broadcasting something useful rather than white noise.

I think the music companies may have something to say about broadcasting mp3s if there is any range in it though!

Re:Legal issues

[Anonymous Coward]

If you're not allowed to do this, then turn off your monitor immidietaly, cause you've been breaking the law for YEARS.

Re:Legal issues

[liquidsin]

well, not so much the music companies...but if the monitor complies with FCC regulations then the monitor manufacturer must have paid for the license for their chunk of the spectrum. so by recording / re-transmitting without their consent, are we breaking any laws? 'cause, honestly, this would be the funniest court case EVER...

Re:Legal issues

[dattaway]

Oh, there are a few ways to increase the output of your monitor by many watts too. These require the case to be taken off and willingness to turn your screwdriver on parts connected to the B+ chassis (about 2000 volts.) Uplugging the computer during this process is optional. Voiding your monitor's warranty and making it a potential fire hazard is your destiny with this procedure.

Brightness is one good way. Want to vaporize some phosphor off the screen? Well, look at that funny transformer with the thick red wire going to the picture tube's top. No, don't put your fingers under that red cap as you'll discharge 30,000 volts. The capacitance stores enough current that it may jump start your heart into transporter mode to a higher (or lower) place in the heavens. Anyways, look back on the transformer where one or two or more small screwdriver adjustments are provided. One should be the focusing voltage for the electron voltage. All this adjustment will do is make your picture tube require prescription glasses when things get fuzzy. The other adjustment dangerously raises the drive voltages of your homebrew particle accelerator into x-ray producing levels. Enjoy.

The other tasty method to injure personal health is to max out horizontal drive voltage. Your adjustment of choice is on the main circuit board that is a minefield of tempting adjustments. The one I am talking about is an adjustable inductor, when tinkered with will lose the monitor's calibration for the horizontal picture width. Its the one adjustable inductor that stands taller than the rest and its frequency is so high, its design require the turns of wire to be a bundle of stranded wire. Yes, remove the powdered ferrite slug out of this coil. Current will now saturate the picture tube's yoke coils. Electronic devices and radios around the house will now bow to your monitor's new elite status.

There you go. Not only have you voided your monitor's warranty, you have just demonstrated why picture tubes are evil particle accelerators. They should be banned.

Re:Legal issues

[Tycho]

Don't tempt me. Also to produce X-rays like that you would somehow have to defeat the X-ray protection circuit. Not impossible just harder to do. Another great thing to concentrate those X-rays would be to unplug or remove the vertical and horizontal deflection coils and fix some of the other components so there is no more vertical or horizintal deflection that occurs in the monitor. The electron beam would then come out as a point on the screen. Which would be great fun as long as you were at least a half mile away when you turned the monitor on.

Re:Legal issues

[gr3g]

If I am not mistaken I believe any one is allowed to broadcast up to 1/2 mile. Or something to that affect.

Re:Legal issues

[Vulture_]

Yet another good reason to replace them with LCDs or something... Spending most of my waking hours in front of a particle accelerator pointed at a sheet of phosphor is not exactly comforting!

By the way, how the hell can it have that much capacitance if it only consumes 100 watts when on?

Finally, doesn't anyone think these techniques could be used to turn a monitor into a directed-energy weapon? Perhaps we don't need humongous lasers after all...

Re:Legal issues

[Vulture_]

Wow... Imagine using that as a weapon...

How much power would it consume in that state?

What!?

[autopr0n]

The TI8x calcs (except the 89, which is just a 92 without a keyboard) all use zilog z80 chips.

The link port is just a 1/16th inch (i think) headphone jack. If you want to listen to audio out of it you just have to plug in regular headphones (not a radio)

Huh?

[autopr0n]

rice boys have always been in north america.

rice rockets

[autopr0n]

Rice rockets are what American Bikers call asian motercycles, Rice Boys are a term used for usualy asian kids who do freaky and fruitless things to their usualy asian cars.

Re:Weird. (OT)

[class_A]

You should see what it's like over here in the UK where people regularly spend more money trying to improve their shopping trolley of a car (ie. Vauxhall Nova) than they actually paid out to buy the thing in the first place.

Old News... My TRS-80 does this already :)

[Chmarr]

Eh... old news. My TRS-80 Model I had a game who's instructions read:

For sound effects, place an AM radio next to your monitor

It was a car racing game... the sound effects made a kind of sense... except they didnt stop when you crashed the car :)

Re:Old News... My TRS-80 does this already :)

[jheinen]

Yeah, I remember that. There were a number of games for the TRS-80 that used a radio for sound. One of my favorites was a space invaders clone. This was back in, oh about '77 I guess.

Re:Old News... My TRS-80 does this already :)

[j-beda]

Heck, the TRS-80 Model 1 was forced off the market because of its radio noisemaking. If I recall correctly, the FCC had let it be sold initially because they didn't think it would be popular but after it sold however many million units they realized that these computer-things would require similar regulation to other common office equipment.

I had a BASIC program that would play arbitrary music over the radio. It had various subroutines that would calculate something or another and thus generate a specific radio tone. The main program simply read in the musical data and called the appropriate subroutine to make each note.

Most games and the like however used the cassette-tape output to make sound effects, or even pretty good voices. "Robot Attack!"

Now where did I put that emulator?

Re:Old News... My TRS-80 does this already :)

[hawk]

>Heck, the TRS-80 Model 1 was forced off the market because of its
> radio noisemaking.

uh, no. It was superceded by a newer model (the III) which was less expensive to build in the configurations people would buy.

> If I recall correctly, the FCC had let it be sold
> initially because they didn't think it would be popular but after it
> sold however many million units they realized that these
> computer-things would require similar regulation to other commo
> office equipment.

it went on the market before the regulation changes, but not by enough to have caused them. It came out, what, Fall of 77? Spring? (hey, give me a break. I'm doing this from remembering my childhoold, not looking it up :). The Atari 800 (late 80? early 81?) was caught in the regulations.

hawk

Re:Old News... My TRS-80 does this already :)

[Chmarr]

Most games and the like however used the cassette-tape output to make sound effects, or even pretty good voices. "Robot Attack!"

Well, that's a sight better than using the cassette relay for sound. BzzzBZZZZBzzzz...

"Bandit Got Away!"

With the right tweakage...

[ebbomega]

That problem could be fixed. It's just a matter of time and ingenuity. There's no such thing as can't be done...

I suppose this is once again contributing to my dream of the geeks raging Beyist Poetic terrorism on the planet and subverting all the stupid (IMO entirely) laws we can eventually work our way around...

Re:With the right tweakage...

[ocelotbob]

That problem could be fixed. It's just a matter of time and ingenuity. There's no such thing as can't be done...

the problem is, with the amount of engineering you'd need to do, it would be cheaper and easier to set up a maildrop in either Canada or Mexico, and have one of the many radio transmitter manufacturers send you their full power kit to that address. It would simply be way too much work to redesign a CRT to put out enough interference to broadcast to a further distance. On top of that, before you could use it, you'd have to get it tested to make sure that it complies with the FCCs emf interference standards. Since the whole point of this design is to increase those emissions for your own uses, the application for your design would be denied. If you decide to go without getting regulated, the FCC would more than likely pop you once they start getting complaints from your neighbors that their TVs, radios, etc, are playing some weird broadcast. Believe me, the FCC has all their bases covered in situations like this - can't have the common man cheapening Clear Channel's airwaves, can we?

wow

[Iamthefallen]

I thought nothing could beat hearing your Amiga 500 floppy drive play El Condor Pasa

Re:wow

[richie2000]

You thought correctly. Nothing can. :-)

Ah, the good old days. The older, the better. I wonder if that disk still works, it's gotta be close to fifteen years old now. But first I gotta find it... Ah, a project! Good, now I can put off work another hour! :-)

Done it before on a TRS80 ModI

[Chas2K]

Trash80 hackers did something like this about 1979 - 80. We also had hacked some hardware to the expansion port to read RTTY and CW. In order to prevent RFI we pulled the case apart and lined it with foil then grounded the whole thing to suppress the noise. The trick is not to broadcast a radio signal but to prevent it. A CB neighbor came over because a Made in China PC switching power supply was blocking out his rig through the power lines. I tried everything from ferrite beads to bypass caps on all the lines and never fixed it. Bought a PS made in Taiwan and never had a minutes trouble since. A lot of the electronic parts coming in from China do not have to meet the FCC part 97, class B rules, or whatever the correct ruling is. Another sweet deal cut by the Feds to favor Chinese goods over American or other countries.

Re:Done it before on a TRS80 ModI

[Anonymous Coward]

We also had hacked [...]

Yeah, riiight.

Re:Done it before on a TRS80 ModI

[Chas2K]

One of the hams in our group was an electronic engineer who scoped out the expansion port and took some specs for a similar interface and designed a board. The local hams etched PCBs and we built a CW/TTY terminal using some ASM code. Next we built up 2N2222 transistor switches and used them to trigger the local loop on the old mechanical teletypes and used these for printers. Crude, noisy, and slow but we had printers for about $1.00 worth of parts and some time inputing Z80 ASM code.
Don't judge other folks abilities and accomplishments by your lack of same.

Wireless

[Faux_Pseudo]

What I want to know is if you can use this as a means of wireless networking on the AM band. Now it wouldn't do any good for my laptop but I could use it for my two desktops to comunicate with. Anyone know where I can buy a AM reciver wireless network card?

Re:Wireless

[Anonymous Coward]

Duh !
plug an AM radio out into your soundcard IN and you got it. If you can reliably recognize 4 amplitude levels, you then got a 2bit*10MHz = 20Mbps wireless link. With an ugly error rate...

Floppy Drive Music

[kotku]

A guy at school years ago used to get his kicks by getting various computer peripherals to play music. The best was a 5 1/4 " floppy drive playing yankee doodle dandy. I think he just drove the head on the drive back and forwards in time with a sound input file. Dot matrix printers could also pump out a pretty tune.

Unfortunately I know longer know this person and a cursory google search turned up nothing on floppy drive music. If anybody has a program to do the same then please post. I don't recommend running this on your own computer though :)

Re:Floppy Drive Music

[Ed Avis]

The BBC Micro had a built-in UHF-PAL output so you could view the display on your television. But it didn't include sound; that came out of the computer's built-in speaker. If you did turn the volume up on your TV you'd just hear noise, presumably it was caused as a byproduct of the picture generation and nobody bothered to filter it out. I remember generating lots of different buzzes and sqeaks from the television by poking random bytes into the video controller's registers and turning up the TV volume.

I also read that the Sinclair ZX80 - a machine with no sound hardware whatsoever - could be made to play notes. There was a program listing in some magazine (ZX User, I think) to do it. Not having a ZX80 (the predecessor to the ZX81) I couldn't try it out, and I never checked whether the magazine's date was April.

Re:Floppy Drive Music

[SuzanneA]

I had an '81 and had a program that did the same thing. If I remember correctly, it made use of the FAST and SLOW modes of the machine to generate 'noise' on the picture. Then you detuned the TV channel slightly, until you got 'music'.

The one I had on the '81 definately worked, unfortunately, it was really pointless, as the act of generating 'noise' in the right sequence to create sounds/tones was somewhat intensive, and couldn't have been used in a game or otherwise.

So thats why...

[hound3000]

I was wondering why the kid with big braces at the end of the row in computer lab was jamming away, and really getting 'in' to our edutainment...

Traffic info...

[geschild]

If you, like me, have your office not 25 metres from a high-way you can now wreak real havoc. Better yet, you now can put _your_ crapy, old, unshielded monitor to good use! It'll be pretty damn hard to track such a weak signal down with a lot of offices around and a bouncing, on/off signal.

Make sure you mangle your voice after recording your fake messages will you? No fun getting caught, besides you want to make yourself sound like a news-anchor.

(For the humor impaired: don't try this at home. Traffic kills more people than drugs.)

Re:Weird. (OT)

[Anonymous Coward]

With the spoiler tilted in the entirely worng direction, hence lifting the rear of the car off the ground. I love those guys. They be so smrt.

Old hat

[JimPooley]

There was a game for the Tangerine Microtan 65 (British 6502 system from 1980, started as a single board, expanded by adding cards) which generated sound effects like this, just tune your radio to 750Khz (the clock speed) and listen...

Of course most people by then had hacked the main board to boost CPU speed to 1.5Mhz!

Kids today with their surround sound and subwoofers, they don't know they're born...

Re:weird, its not working - but it does! :))

[leibnitz27]

But I've been in one of Ross Andersons lectures where him and Markus demonstrated tempest working against a laptop. Just using LCD won't protect you, see Here (google cache - page seems to be missing) and Here

Just one little detail

[Cine]

Emitting noise into the air is illegal in a quite a few contries...

Re:Just one little detail

[CProgrammer98]

All this program is doing is modulating the EXISTING rf that's coming out of your monitor in a more useful way by calculating and displaying an image that will cause the modulation to be at a particular musical frequency. It ISN'T causing your monitor to emit any more radiation than it already was, it's just "un-randomizing" it.

Hmmm.....

[MonoSynth]

If you can play a DivX-video on your CRT, receive the signal that your screen transmits with your AM-radio, record the signal as if it was music, encode the track as mono mp3, and play the track again on your screen with this program, can you get a quite good quality then?

Re:Hmmm.....

[Anonymous Coward]

why don t you do the math to answer your question ?
you know the refresh rate of you monitor, it s resolution, so you know the maximum frequency you need to be able to record analog.

Good description of van Eck

[English Guy]

Good description of van Eck phreaking in Cryptonomicon by Neal Stephenson or in this article (which is quite a large pdf)

Great! Thanks!

[perlprog]

Now, soon, we will not be able to use our laptops in flight. Woo!

Re:Great! Thanks!

[jrockway]

If you have a CRT display on your laptop, it's not a laptop anymore (it's a "penis crusher" or something)...

Not quite...

[Lispy]

Not so easy, radio is ONE way...
Remember when they said on the web everyones a sender? Thats what they ment.

Of course equipping EVERY PC in your flat with a radio AND a Monitor you could get this thing to work. Of course you would have to assign a dedicated Frequency to every machine.
But then again, you sure would need some nice errorcorrection since the quality wont be too good. And that could bring your transferrates down...in fact, i guess you could do better using two walkietalkies instead...;-)

Nice idea though, i was thinking about sth. like that for some time. Like streaming data via radio at certain times, but then again...i could just use a decent broadband connection to do the same thing two way...

Lispy

Re:Not quite...

[Anonymous Coward]

And you couldn't use your monitor at the same time, 'coz it would be busy transmitting data...

Re:Not quite...

[Anonymous Coward]

And your dog would start glowing in the dark.

Um you guys will probably kill me for this ...

[jstockdale]

... but will someone port this thing to Windows so the less 31337 :P members of /. can have a play with it.

Not that I don't run linux ... but ... um ... oh just think of the children and port the damn thing ;)

*cough* xp *cough*

a better proof of concept

[alphaque]

this project is an excellent proof of concept to people who would otherwise display incredulity that something like tempest is possible. well done to the author.

a better, and perhaps much awaited POC, would be to have the code read a given text file on the box, then with a text-to-speech convertor, convert it into speech and the flash the speech as a series of monitor images.

then walk by with an AM radio, and listen to the file being read to you. a demo of this capability would definitely freak out some people who routinely scoff at tempest-type initiatives as being too science fiction and undoable in the real world.

something as simple as this, downloadable over the net and requiring nothing more than an AM radio would prove that not only is government capable of doing it, but lil joe next door could be reading your emails without even breaking into your machine.

now, wouldn't that cause em to sit up and take notice.

Neighbourhood Prirate Radio

[spiro_killglance]

and not a damn thing the FCC can do about it,
since the equipment (the Monitor/Computers) has already be licensed by the FCC. You'd probably need a whole lot of boxes, though. And to make
sure they were all in phase would not be easy.

Or play it through your Cell Phone

[waimate]

Yeah, it's not much different to playing tight loops from your old 8080 or 6502 based board to your AM radio.

But the 21st century version of this is to take your multi-gigahert Pentium class processor, and phreak your way into your multi-gigahert mobile phone. Not only play row-row-row-your-boat, but also phone your own cellphone and leave it as a voicemail. Now that'd be cool!.

rock group reunited?

[Anonymous Coward]

So does this mean the 80's rock group Europe will reunite?

Receiver

[Stephenaa]

Anyone up for doing a receiver only using a standard PC and what ever lies on an ordinary desktop (paper, paperclips, eraser etc.) ??

I have a quality monitor AND I CAN'T HEAR CRAP!!!!

[Evil MarNuke]

> depending on.. ..the quality of your monitor you will hear good voice.

Even when I had the antenna on them monitor I couldn't hear crap!! I paid two grand for that hunk of junk. That old monitor works fine, and that was given to me!! I'm pissed!! I'm writting Sony!!

Oh, this is a good thing you say? Well how am going to block Dr. Luara?

Evil MarNuke

This is an old story ...

[marko_ramius]

... when I was in school, WAY BACK WHEN, we had an instructor that liked to play a tape of a S/360 (forget the model) that could play music through radio interference. He just had to put an AM radio on the main cpu box, load a specific deck of cards, and various tunes would play.

I believe he had happy birthday, William Tell Overture, and a few other snippets.

The best one was, however, when he had the computer play taps for itself when it was being replaced by a modern S/370.

mr

Alaire

[KarmaBlackballed]

I heard about an Alaire presentation to a computer group back in the early 70's that consisted enirely of music generated by placing an AM radio next to the Alaire computer. Maybe someone here knows more about that event. I know it has been written about before.

The more things change, the more they seem to stay the same.

Sweetcode had ya beat!

[TheLocustNMI]

SweetCode had you beat on this one! It's a great little site. Imagine, if you will, Freshmeat with all the chaff removed.

Space Invaders for GRUB

[SgtUnix]

ErikYYY also has a Space Invaders for GRUB you might want to check out :-)

Freedom of the (electronic) press...

[sandgroper]

...is no longer the exclusive domain of those with a webserver.

Very cool demo.

Ahh... the TRS-80

[TopShelf]

I can't recall the game, but way back in the days of yore there was a game for the TRS-80 that created sound effects via a radio that you'd set up near the box. Anybody else recall classics like that?

Eek, that's annoying.

[Nuncio]

Who would bother with such a thing?!?

Re:Eek, that's annoying.

[Anonymous Coward]

I did something like this once to send a person's password in morse code to a near by AM radio...

fm?

[Psychopax]

I wonder why things like these are posted on /. I thought it was a news site, not a site for software announcements.
Is slashdot getting freshmeat or what?
j.

Re:Weird. (OT)

[biohazard99]

Is that like the Chevy Nova, the car they couldn't sell in Mexico (No == No && Va == Go) The Chevy NoGo

Talking about ancient times...

[hey!]

I have a vague recollection of reading about something like this in an old IEEE Annals of the History of Computing an article on EDSAC, the first stored program general purpose computer (ca. 1950, used mercury delay lines to store data acoustically). They used a radio to listen to the interference generated by the computer; a crash sounded different from normal operations. I believe this was not uncommon in the days of behemoth computers and no government emissions regs.

Re:Talking about ancient times...

[GTMcD]

About 1965 Richard Smiley, a student at Carleton College in Minnesota, wrote a program that could play music (sort of) on an IBM 1620. You could listen to it on an AM radio placed near the machine. The 1620 was a variable word length machine, and the word length affected the time it would take to accomplish a task, thus changing the radio signal. Smiley exploited this variation to generate musical tones. IBM included this in the contributed program library that was available to all 1620 users.

Anybody want to try to communicate?

[Anonymous Coward]

We could use this to send morse code and our /. id numbers for identification. This will work like what the hams did when the had fixed frequency transmitters and variable frequency receivers.

Yes, yes, yes! Finally!

[linuxrunner]

Now we can get online and give Dr. Laura some REAL competition!

Don't forget to listen tonight at 9.....
Just make sure you're within a 20 foot radius to hear me!

Re:Weird. (OT)

[Seraph]

Nope.

Sinclair Spectrum speech synthesis to tape

[Richard Kirk]

I still have a program somewhere for the Sinclair Spectrum, that generated speech. You could save data to a cassette recorder, so with the right arrangement of ones and zeroes you could reproduce recognizeable speech. This might have run on the Z80.

The equivalent these days would be using a CD writer to make simple holograms. I vaguely remember someone at a UK university doing this, but I forgot the details.

Re:Sinclair Spectrum speech synthesis to tape

[Ed Avis]

Are you talking about the speech program published by Quiksilver? That's not what I am referring to, I believe that someone managed to make the Z80 itself produce notes (since most older computers make some kind of humming noise depending on what instructions they are executing).

Hmm..

[Uberminky]

Hm, that's pretty cool that you can apparently hear it on your radio. I've noticed something I assume to be vaguely similar.. I've found that sometimes when I have the stereo (hooked up to the computer) turned up, I can hear strange sounds whenever I do certain things on the computer. For example, it might emit one tone, and then when I move the mouse over a different button or hilite a menu, it will emit a different frequency. I always thought it very strange but didn't think too much about it. Anyone have any good explanations for it? I suppose it's just the CPU interfering with the soundcard.. Oh well. I thought it was cool. ;)

Re:Weird. (OT)

[biohazard99]

I stand corrected, but let's face it, after the ~72 model year, the car wasn't the same, much like the rest of the American auto industry.

ZX-81

[ThierryD]

Well, back in 1983, I had a Sinclair ZX-81 (also resold in the US by Timex, I believe) with a whopping 1K or RAM.

I purchased a program that did exactly that, but wihth the mother board.

Put a radio next to the ZX and you could hear Jingle Bells. Not great quality, but pretty neat (in those days).

Almost 20 years later, today's computers still can not beat the power of a ZX-81!

Re:ZX-81

[AndroidCat]

Oh? And what kind of numbers are you getting with SETI / RC5 cracking? I just got a 486/66 online and the numbers suck -- I guess I should have fixed my ZX-81 (modded for a 32k ram chip). :^)

Interference

[N8F8]

Because I'm a cheap bastard I don't have cable tevelsion (cable internet tho). If I turn on my laptop anywhere near the TV, VHF channel 3 gets scrambled. Same thing if a big truck goes by. Another wierd thing is that if I leave my speakers turned on I can hear entire CB conversations broadcast from the speakers -with the computer turned off. I'm pretty sure the speaker thing is the CB transmission inducing through the powerline.

Re:Interference

[b1t r0t]

Back in '78-'79, I had to turn off my TRS-80 whenever the family wanted to watch channel 12. The computer was in a far corner room, at least 30 feet from the antenna.

Re:Interference

[GigsVT]

The CB problem is because those truckers are pushing 100-300 watts or more. I think 4 watts or so is legal for CB, but probably 95% of truckers use a amp of some sort.

AM will rectify when it gets picked up on your speaker cables, sort of like the old crystal radio, it doesn't take much to create a simple AM radio.

There are some measures you can take to reduce the interference (even though you shouldn't have to legally, it's them that is breaking the law).

Try ferrites everywhere, especially on cables that have a grounding sheath. This will choke off current from the ground sheath.

Keep cord lengths as short as possible. Move the equipment to the other side of the room and see if that helps.

You can also wrap your whole house in chicken wire. Just make sure the chicken wire has a good RF ground, and also make sure your neighbors don't call any mental health organizations. :)

Re:Interference

[RollingThunder]

They don't need to be pushing that much power at all.

I had a CB a few years back, that was just a tiny bit "tweaked". Instead of 4 watts on main and 12 on sideband, it pushed around 6 and 16.

Once, I was sitting in my truck in front of my parents house, chatting with some CB friends. I came back in, and my parents had heard the whole thing! It turned out that the length of the SPEAKER CABLE was an exact match for the wavelength of one of the channels (or a multiple thereof, not positive which).

The amp was on, but not playing anything, and somehow it picked up this signal off the speaker wire and spat it back out, amplified slightly, just enough for my folks to hear it.

A 300W rig (which I never saw, people would get ridiculous power from a simple 30W amp) would let me do that from two klicks away, easy.

Re:Interference

[ryanwright]

The CB problem is because those truckers are pushing 100-300 watts or more. I think 4 watts or so is legal for CB, but probably 95% of truckers use a amp of some sort.

Yup. When I was a teenager, the people down the street were pushing x hundred watts out of a home CB setup. Every time they would key up, the speakers connected to my Amiga 3000 would amplify their voices at annoyingly high volume levels. Scared the hell out of me the first time it happened. A quick conversation with them solved the problem for good. :)

This is how the FBI soft-pgp-key snatchers work!

[Anonymous Coward]

This is how the FBI soft-pgp-key snatchers work.

No big news.

This is the basic premise of much of the three small new departments of the US gov, one under each branch of the gov, "amplify" your pgp keystrokes.

Thats why i use combined mouse movement as passphrase constructor.

BTW... this monitor method is PRIMITIVE, the best tempest keysniffers use bursts of cold-motherboard-ram timed accesses interspersed amoung hard disk chatter IO to never get spotted easily.

Magic Lantern

[3seas]

Hmmm, works on all systems... watch ... uh..errr hear them keystrokes. A lantern that you can hear as well as see?

PGP Secure Viewer

[Anonymous Coward]

Somebody wanted to know how this works in an earlier post.

Essentially, when you reconstruct a screen from the EMR emissions of a monitor, you lose a lot of the contrast and the image is going to be blurrier. So, if you are viewing nice crisp black text on a white background, it will still be readable even after being mangled by tempest. But, if you are looking at blurry dark gray text on a lighter gray background, it will probably be unreadable by your eavsedropper who is looking at a less-than-perfect copy.

Altair Star Trek

[airship]

A buddy of mine had an Altair Star Trek program that used the same principle for sound effects. You'd fire phasers at a Klingon vessel and an AM radio sitting on top of the case would put out a cool phaser sound. Pretty high-tech for the mid-70's.

Diamond FireGL 1000 Pro & FM

[scott1853]

My girlfriend used to get pretty pissed because when my video card would start doing anything 3D, it would cause a hum on the FM station she used to listen to. I think it was in the 100-105 range. The faster it performed 3D ops, the higher the pitch of the hum.

I made an openGL app that simply resized a spinnging sphere to random sizes. The smaller it got, the faster it moved, the higher the pitch. I never tried making it play music though.

Re:Diamond FireGL 1000 Pro & FM

[nightguy]

That would make a nifty WinAmp plugin - synch the images to the musical notes and you'd have tunes throughout the house!

Re: Sweetcode ...

[Omniscient Ferret]

This might be a temporary quirk, but right now, sweetcode.org works better.

Do you get more power with a bigger display?

[sh00z]

Can you use LinuxDC and your $50 Dreamcast to send this to a big-screen TV for better range? I'm willing to try it.

Info on TEMPEST, van Eck, HERF, etc

[The_Pey]

The number of ways to exploit TEMPEST has inspired quite a few authors. A real good primer is Information Warfare by Shwartau. There are number of great chapters on this sort of thing.

While your monitor may also be used to transmit AM signals, ANYTHING that conducts may be used as an antenna to receive or transmit. In light of this, devices have been built for the modest price of a few hundred bucks that direct a High Energy Radio Frequency (HERF) pulse at a car, building, etc. Effectively blows out any electronics that it is directed against.

Re:Info on TEMPEST, van Eck, HERF, etc

[Anonymous Coward]

HERF? C'mon! That hoary old subject has been science fiction since the mid seventies at least and it's STILL SCIENCE FICTION TODAY!

Yes, nuclear warfare will generate some serious EMP that can destroy an awful lot of electronics, but they have one thing that the so-called HERF alarmists overlook: Energy! Lots of it. We're talking about a nuke, after all.

Can HERF be real? Can it be made the size of a can of cola? Sure. The only thing you alarmists haven't figured out is what's powering this bugger. The closest anyone has come to the HERF weapon are the Soviet era Gyrotron radar tubes.

I was an intern for a certain DOD installation many years ago where we figured out how to conduct electronic warfare against such things. HERF? Sheesh. Wake up and smell the bullshit.

Re:Info on TEMPEST, van Eck, HERF, etc

[Black Acid]

HERF is an interesting weapon. The best web site about it I've found is http://www.codexdatasystems.com/herf.html , which is now unavailable, although you can view the entire archive of it at http://web.archive.org/web/20010814122813/http://w ww.codexdatasystems.com/herf.html.

Original Tempest-AM

[Anonymous Coward]

Here's the original Tempest-AM that the Tempest for Eliza use for its routines:

http://silcnet.org/priikone/english/programs.shtml #tempest.'

It's got a longer introduction to the subject in the README file.

who the fuck do you think you are?

[posmon]

and what are you doing with my email? cunt.

Re:who the fuck do you think you are?

[posmon]

yeah, that's really fucking flamebait, isn't it. responding to someone who thinks he's the dido's dildo, just because he can change a couple of words into symbols.

fuckarse moderator.

harumph. Another Johnny-Come-Lately

[hawk]

While remembering the 8bits and their tricks is impressive, it was hardly new. This was done on IBM's and others at least in the 60's, and possibly the late 50's.

Additionally, line printerss played Jingle Bells . . .

hawk

Re:SPAMBOTS C'MON DOWN

[Anonymous Coward]

Now, that's good comedy

PDP-7

[hawk]

Yes, there was such a beast. And the PDP-6, which was the predecessor to the 10. PDP 1-11 were all designed, but not all were built.

However, these are still later than the playing of such tunes on mainframes in the 60s

hawk

Re:I have a quality monitor AND I CAN'T HEAR CRAP!

[buckeyeguy]

Think maybe it has something to do with the newer monitors that meet (or have to meet?) "low-emission" standards?

Quite a cool hack...

[Strangely Unbiased]

But not as cool as taking your photo using your monitor.

Re:harumph. Another Johnny-Come-Lately

[dattaway]

This was done on IBM's and others at least in the 60's, and possibly the late 50's.

This still won't stop some talented individual who is handy with patent applications from filing today. Be warned...

Old hat, nothing new

[SpacePunk]

This sort of thing was being done on Sinclair ZX81's wayyyyyy back in the early 80's. Check back issues of Sync magazine. Been there, done that, nothing more to see here, move along.

There was a change ~1980

[hawk]

The FCC tightened the requirements at about 1980. Some things were grandfathered in, but newer models had to comply.

Take apart an atary 800. It has an SS50(iirc) edge connector that was made for expansion. They had to give that up and encase the thing in about 1/8" metal to handle the RF. A side effect was a serial interface, making for slow floppies, even for its day. ON top of that, the floppies weren't interleaved at first, so that after reading a a sector, theentire disk had to spin around again before reading the next. ROM C in about 81 added interleave. My demo unit preceded this (heck, the 800 had serial number 49. I knew the owner of IMSAI #13 at the time, too). On top of that, it was unable to keep track of which track it was on, so every track change resulted in a move to 0, then counting its way out . . .

Apple redesigned the II's motherboard to cut rf, and shielded the inside of the case. I don't think this was the same time as Rev 6, which cut the purplish tint on text (by killing the color subcarrier on text lines, iirc). And the ever-popular Supermod II wadesigned by apple, but farmed out for production, so that the II wouldn't be making an RF broadcast.

These continue today. One of the reasons your laptop has an external power supply is so that the supply can be certified, rather than sending the whole laptop for certification with every minor change.

hawk

Beeping remote?

[BillyGoatThree]

Why would I hear beeping over AM on a remote? They are all infrared (and the original ones were ultrasonic). I've never heard of an RF remote...

Re:Beeping remote?

[ocelotbob]

Yes, I know most remotes are IR. However, the phenomena I'm talking about is fairly well documented; there are several faqs floating around on the internet discussing the subject. Because of how AM radios work, any localized source of radiation of sufficient strength, no matter what the frequency, will cause interference. Its similar to how a thunderstorm will cause pops when listening to the radio.

May be illegal in the US

[uslinux.net]

In the US, the FCC allows anyone to broadcast an AM signal under Part 15 of the FCC rules, so long as it doesn't exceed something like 47 microvolts at 100 meters from the property line. Unfortunately, most AM receivers need at least 300 microvolts to detect a signal and the signal degrades logrithmically, so unless you have a very large piece of property, AM broadcast will probably be illegal for you.

Disclaimer: I'm not an RF engineer, but I have worked with several in attempting to obtain an AM broadcast license for our college radio station a few years back. Take it for what you will, and understand that the FCC *probably* won't come after you unless people complain. But, if people complain, you can expect them to triangulate your position, take your equipment, and fine you heavily.

Re:May be illegal in the US

[Anonymous Coward]

You're broadcasting already, the difference is what you broadcast.

Re:May be illegal in the US

[glwtta]

Read some of the new laws - using computers is illegal in the US. Period.

linux....

[guinsu]

Well, the software only works on Linux, which I assume means that Windows isn't suceptable to tempest eavesdropping at all.

You lazy bastard.

[Anonymous Coward]

The code's GPL'ed -- port it yourself you lazy bastard.

other eminations

[emoeric]

my computer speakers make a noticable buzzing noise about 2 seconds before my cellphone (nokia 8260) rings. Consistently. Its good because i can turn down the speakers and answer the phone after like one ring. I assume this is an unintended conflict of sharing emission frequency or somesuch.

Random? Relevant? who knows!

Re:Weird. (OT)

[Anonymous Coward]

people regularly spend more money trying to improve their shopping trolley of a car (ie. Vauxhall Nova) than they actually paid out to buy the thing in the first place.

Yeah, but you should see these Free Software people on the net. They spend more of their valuable and limited time here on Earth trying to build and improve half-functioning software when they could go out and pay to get a working thing in the first place.

See?

HAL 9000

[Mignon]

Here's what I'll listen to first when I get this working.

Who needs a radio when you've got speakers?

[almightyjustin]

My PC's speakers pick up AM radio on a frequency of about 1100 if you hold the volume knob just right...I remember I hooked up a big headphone extension cord and a microphone to the microphone jack and I could record pretty good sound off the radio station...I guess it's my cheapass AcerMagic S20 soundcard....

Tenpest

[darkonc]

For those who don't know, "tempest" was the unclassified name for a project (and specifications) designed to allow/prevent the capturing of intelligence information using the EMI from computers... As quoted from the top of the referenced page:

Across the darkened street, a windowless van is parked. Inside, an antenna is pointed out through a fiberglass panel. It's aimed at an office window on the third floor. As the CEO works on a word processing document, outlining his strategy for a hostile take-over of a competitor, he never knows what appears on his monitor is being captured, displayed, and recorded in the van below.

*sniff*

[hawk]

> I stand corrected, but let's face it, after the ~72 model year, the
> car wasn't the same, much like the rest of the American auto industry.

*sniff*

That was the end, yes. 71 might even be a better cutoff--72 was the year GM emasculated the big cars, dropping down to two barrels. I had a '72 Impala 400, and wish I still had it. The '71, thought, with the 4bbl, was rated at about 50% higher horsepower. And it went down from there. After the carb barrels, they started lopping of cylinders.

Should detroit ever ship a 3 ton vehicle with a 400cid engine again, I'll be the guy you see on the news standing at the front of the line at the factory gates . . .

hawk

Re:*sniff*

[biohazard99]

If it makes you feel better, my 78 Buick Electra had a factory Rochester Q-Jet on top of the mighty Olds 403 Small Block, 4300 Pounds curb weight, 25 gallon fuel tank, 190 Horsepower/310 Lbs/ft torque, oh yeah, It got 12MPG anywhere anytime

Re:*sniff*

[ThatComputerGuy]

This will probably make both of you feel bad, but about a year and a half ago I was lucky enough to be able to buy a 70 Trans Am (400) Ram Air III, with plenty of engine/suspension work done.

In response to your unasked question, yes, it seriously kicks ass.

Re:*sniff*

[JJorda]

If it makes you feel better, my 78 Buick Electra had a factory Rochester Q-Jet on top of the mighty Olds 403 Small Block, 4300 Pounds curb weight, 25 gallon fuel tank, 190 Horsepower/310 Lbs/ft torque, oh yeah, It got 12MPG anywhere anytime

Consider yourself lucky to get something in the late '70s, my '82 Chevy Caprice has a dinky 2bbl carb on it's 267 small block putting out an impressive 115 horsepower 20 years ago, and age wasn't kind to this motor. For a 2+ ton car, 115 horsepower is not enough. Scarily enough, there were 2 engines offered that year with less horsepower than mine! '79 was the last year for a decent motor from GM in the big cars until the early 90's.

Re:Back in ancient times (OT)

[dohnut]

Yeah, it's more the physical situation that the computer is in. The power cord isn't long enough to move the computer out to where I could work with it -- comfortably anyway. I had to slide the system into place, then hook up the peripherals and power. It's really entrenched, it has physical barriers on both sides and another server on top of it.. I should take it down one of these days anyway. It's running a fairly old kernel, there are no (known) remote exploits, but there are a few internal exploits. I'm the only user however -- It's a monogamous relationship.. It's been such a good kernel, I beat on it and it just asks for more.. I just don't think I can bring myself to pull the plug.. Huh? No, I'm not in love with my kernel! Wha? I meant beat in a figurative way! Hey! Where are you taking me?!

I need to get back to work..

troll??? huh?

[hawk]

uhh, hello? Put the crack pipe away. You do have me baffled, though, as to how anyone could *possibly* call it a troll . . .

hawk

Re:troll??? huh?

[The Pi-Guy]

And why that is modded 2, no descriptors is beyond me, someone's having a weird modding day today... --joshua

Floppy drive music

[infinite9]

This reminds me of a program I had for my Amiga. It would play Greensleeves by moving the seek head in the floppy drive at varying frequencies. There was one for the c64 also, and I'm sure it works on PCs too. Anyone know if such a thing exists for a PC?

You have no chance to amuse

[Anonymous Coward]

waste our time!

Dual Monitors

[mfos.org]

I have twin 21" HP's, I wonder if I could do a duet. Even better, get a 17" and that could be a tenor.

Talk about pirate radio

[Anonymous Coward]

Embed this thing into a worm, let it proliferate at some code red level for a few weeks, then simultaneously activate all the infected hosts to broadcast your plans for world domination.

Geek Christmas Album

[mfos.org]

We've got the barking dogs christmas carol cd, why not have a singing monitors cd?

Ok, so how about a MonNet?

[vulgrin]

Ok, so you can transmit over AM. Now you just need to have a AM receiver built into your PC, add in some software to decode the signal, build a protocol and you have a Monitor based network.

Wonder what the baud would be... :)

VtM
Sigs are for wussies

this reminds me...

[Anonymous Coward]

of the metal plate in my head. If I stand close to high-voltage power lines, I can watch DVDs by crossing my eyes. Only downside is my surgeon was too cheap to give me DTS so I only get mono.

Re:harumph. Another Johnny-Come-Lately

[BrookHarty]

And my commodore floppy drives and 300 baud modem played Jingle Bells also.

Re:harumph. Another Johnny-Come-Lately

[Anonymous Coward]

Ogg say femur on skull make big noise also. Big black rock say so.

Additionally, mastedon inestine with rock go "white christmas".

Receiving the signals?

[ascii-kekkonen]

Would it be possible to receive AM transmissions with your monitor?

FYI...

[Anonymous Coward]

This is KC9ALV, too lazy to reg, and 10.000 MHz is
the broadcast frequency of WWV. The clicks you
are hearing in shortwave radios tuned to that
frequency are from Boulder, CO, not your monitor.
They indicate the time. Listen for awhile and
you should hear a voice speaking the correct
time every minute.

As far as default monitor noise - My monitor
nails all signals on 14.313. I guess I should
be considering myself lucky. Also, my PC drives
my HT nuts. On the other hand, keying the HT
drives my computer's speakers nuts. It's a mutual
dislike. ^_^

As far as disrupting radio communications goes, I really can't encourage that, but I suggest
you go to Radio Shack and get one of those 150-in-1 kits and make a real radio transmitter. Besides, you might learn something about
electronics, and that's always useful.

Wow an Art Bell link.. on slashdot?!

[xenyz]

Never thought I'd see the day..

Severed Heads

[Anonymous Coward]

Severed Heads not only did this twenty years ago, but put it on LP under the title 'Dance' as heard on 'Clifford Darling Please Don't Live in the Past' and elsewhere.

Re:Severed Heads

[Anonymous Coward]

Using CPU EMF to create music was de rigueur in 1977-8. I remember writing songs on my Exidy Sorcerer Z80/CPM singleboard.

And If I Bite Into My Monitor Cable...

[Anonymous Coward]

...I can "hear" the music in my fillings!

Ahh...not super broadcasting but....

[Mashiki]

Doing some home experimentation, I can get a broadcast range of roughly 50ft with a small trasnistor radio and my home computer. In the city it's less due to the fact my city uses low-pressure sodium lighting, which kicks up alot of AM interfearance, try listening to a city 25mi away that broadcasts at 15,000watts and barely being able to pick it up.

Regardless, I can pick up the AM boomers out on the east coast, 1210 and 1290 both broadcasting at 50,000watts, but it might have something to do with broadcasting at a higher range, the 15k watt job is only 900.

So, comeing back to it...does that mean that the higher your range the better your broadcasting ability? Quite possibly, maybe someone with more time can do some better experimentation.

Re:Ahh...not super broadcasting but....

[Dr. Mutex]

You get the east coast stations (at night, yes?) because there is nobody else on that frequency (at night) and it bounces off the ionosphere. Your "nearby" station may very likely be using a directional antenna system (many AM stations are required to) that doesn't cover your area. Typically these small stations are required to drastically reduce their power or shut down alltogether at night. You may have a lot more interference (dammed lights) around 900kHz too.
Radio propagation is way too complex to generalize about higher being better. Within the range you mention, they should be about the same.
(I will gladly defer if any Hams or RF Engineers care to respond)

What's That Song?

[Skip666Kent]

I've got it on a Ventures disc somewhere...Besame Mucho perhaps?

Generate AM Stereo Broadcasts With Your Monitor

[Ferd Lamarche]

Well... That's pretty cool. I'll have to figure out a way to make in broadcast in AM stereo.

Musical smashing disk heads on an Apple II

[hoggoth]

A long time ago I had written a 6502 assembler program on my Apple II that tried to seek track -1 on the floppy drive, then paused a set amount of milliseconds, then did it again.
I got it so I could play songs by the vibration of the drive from the read head banging into the end of it's arm.

This did, however, void my warantee.

Re:harumph. Another Johnny-Come-Lately

[The Pi-Guy]

"line printers played Jingle Bells" And now it's scanners that play Ode to Joy (www.eeggs.com) :) --pi

Useless, except for gov or corp espionage

[mdonalds]

If you can broadcast tunes from your monitor, then you can also translate your monitor's radio signals to a picture. This does happen.

While I was at the Navy, we would get regular security checks from a team to ensure that what was on our monitors could not be picked up from outside the building. Supposedly power and analogue phone lines are also checked.

Art Bell @# +4 ; Informative #@

[Anonymous Coward]

snorts cocaine. BTW, Whitley Strieber is also
a con artist.

Thank you and have a nice day.

Informative: TI Calculators do it too

[fractaltiger]

This is interesting, since years ago, I had the custom of using sitting at my computer late at night with my walkman on.

The walkman picked up interference somewhere between 86 and 96Mhz, and the noise drops out when my screen went black.

My TI86 calculator also seemed to emit radiation around that area of the spectrum, except that it's quiet until you type "2 ^ 1000" or "54 !" and press enter. Or tried to run a graphical strange attractor algorithm for a few minutes. I had some fun with my TI by placing it at different angles near my radio and imagine the waves and the radiation... all generated with 6 Volts.

How do we even stay alive with so much "radiation" around us anyway? ;-)

Drives...

[Mattsson]

Wasn't there a crack-intro on the Amiga that played musik by moving the floppydrives head at different speeds? :-/

FCC ID Number Search

[Black Acid]

On a related note, be sure to check out the FCC-ID Number Search page. I used it to find out my Logitech Cordless mouse operates on 27.045MHz. Could be great for van Ecking arbitrary devices.

VGA port on the back of your laptop

[billstewart]

I don't know if this will work without a monitor - probably not, though I've seen television interference without one. But your laptop probably has a VGA port on the back that you could plug into a monitor to play the funky music.

Now I know

[npgmr]

why my computer is emitting sound at different frequencies..

Basically, it's more "quiet" if I feed em some jobs, and it's noisier when it's idle.. haha

I've ported tempest-am to Windows

[Anonymous Coward]

The porting was a piece of cake with the help of DJGPP and Allegro.

The problem is that I don't know how to get all the variables needed to get a usefull radio-signal. I can run the program and get a fancy pattern on the screen, but there's nothing on the radio.

Re:I've ported tempest-am to Windows

[Anonymous Coward]

cygwin or mingW should do a rather good job too...
as for your "variables", why don t you use the windose version of SDL ?

Re:I've ported tempest-am to Windows

[Anonymous Coward]

I tried using cygwin and mingw, I couldn't get it to work.

Re:I've ported tempest-am to Windows

[Anonymous Coward]

If anyone actually ports this to windows e-mail me at revolution@ureach.com please.

Somewhat O/T, but still interesting...

[longbottle]

This reminds me of how much I use sound as a troubleshooting tool... I'm probably I'm not the only geek to use the sound of fans, floppy drives and hard disks (not to mention IOMega's Zip drives' infamous "click of death") as a general indicator of their health. Does anyone else use sound as a general health indicator for their systems? If so, how do you do it?

As Florian mentioned, my CPU fan is also an indicator of the current load. Is this a common occurance? Anyone else familiar with it?

Re:A Condensed History of the Penis Bird

[Anonymous Coward]

Our network, in its normal state, is just fine. We have it a lot better than most universities and things have gotten better over the last couple of years.
Therefore, I'd like to retract my previous negative posts about the structure of our network. Futhermore, I'd like to re-reference all of those posts againsts the users of this network.
)
( \
X
8====D
That's right, you, the abusive, users of this network suck. It is your fault--completely--that our outbound is stuck at 95%. YOU, the ppl that continuously output large amounts of traffic, for extended periods of time, on an hourly and daily basis. You were the reason that a network cap was instigated and you are the reason that we need an, albeit much more effective, network cap.

May your stupidity not go unpunished.

Encoded not encrypted

[greygent]

Encoded not encrypted...there's a distinction.

Windows?

[foxxo]

Does anybody know of a WINDOWS program that does this? (Not all of us use that "linux" thing you're all so excited about)
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Re:I have a quality monitor AND I CAN'T HEAR CRAP!

[Evil MarNuke]

I doupt we can walk in and over throw a government we disagree with without reason. So all we could do was wait until they fucked up. Of course the bad thing is we armed the Taliban to gain power. Opps. Well they fucked up so now we can take them out of power. HORA!!