[Nirvous] managed to get composite video out working on the DIDJ. He knew that the CPU had the ability to generate the signal, and that similar devices already had this capability. After studying some DIDJ teardowns he figured out which connection on the processor should provide the appropriate signal. Next was the firmware side of things and after sifting through a lot of code he was pleased to find a flag that looked like it would enable video out. Some cross-compiling, soldering, and a low-pass filter got it to work.
If you’ve been hacking around on the device you might try this. The CPU uses a ball grid array so soldering is a bit difficult. We covered a BGA soldering trick that might be just the thing so check it out before you retreat into your soldering-fortress of solitude.
Above is a new demo video called Phasor developed by [Lft]. It is run from an AVR ATmega88 and a few passive components, and the result is pretty amazing. [Lft] goes into detail about the tricks he used to get this up and running. The chip is clocked at 17.73447 MHz which is exactly four times the frequency of the PAL color carrier wave which allows him to fake a smooth signal. He also uses a timer trick to get the voltages that he needs. The work done here is beyond hardcore and quite frankly we can’t believe he managed to fit all of this into 8.5 KB of program space with just 1 KB or RAM. We wonder if there’s enough room there to add sound and color to the AVR Tetris project.
[Ben] built an AVR based Tetris game that uses a TV as the display. He linked his project in a comment from the AVR Tetris project featured last week. His work taps the power of his own tvText library to handle the composite video out. Using a TV takes all of the hardware work out of the equation, leaving just the composite jack and a few buttons to connect to the ATmega168 and its 20MHz clock. We’ve embedded the game play video after the break. It’s black and white but also clean and crisp.
[Ben] didn’t include music with his build but another commenter, [Eric], has started to work on that. We can’t help but think that they both should have tipped us off sooner about their projects.
Continue reading “More AVR Tetris”
[bunnie] posted this pretty slick way of getting composite video out of a Chumby. The Chumby is an open source connectivity device that has already seen some decent hacking. This modification, done by [xobs] isn’t too difficult. It only requires patching into some pads on the motherboard and loading a custom kernel to support the external output.
[Ben Heck] posted this writeup about getting S-Video/composite out of an Atari 2600. This is actually the hack of [Longhorn Engineer], who showed it to [Ben] at a recent event. If any of you have tried to play these classics on a modern TV you may have found it to be quite difficult. If you manage to get it physically connected, through adapters and such, you may still have video issues. This alleviates that issue completely. After you solder this in, your Atari has native composite/S-video. As you can see in the video after the break, it seems to work pretty well.
Continue reading “S-video from an Atari 2600”