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?

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.

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...

[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.

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.

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 :).

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.

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.