Atari 2600 Recreated In An FPGA

Behold [Retromaster’s] field programmable gate array implementation of an Atari 2600. The processor and video chip have both been built in the 100,000 gate Spartan-3E FPGA, with connectors for audio, video, and a Sega controller. The output signals are generated using two DACs made from R-2R resistor ladders, much like the project we saw in August. [Retromaster] included functionality for the system switches (difficulty and select) in the controller itself. There is VHDL code and board details available if you want to make one of your own. To help in making that decision we’ve embedded video of it after the break. Continue reading “Atari 2600 Recreated In An FPGA”

Building A Discrete Digital-analog-converter

Want to take back control of how your digital audio files become sound? One thing you can do is to build your own digital to analog converter. This one is made from discrete components, centered around a resistive ladder. Yes, there are a couple of integrated circuits in there which are used for demultiplexing the incoming signal but the magic happens in that R-2R network. The project is an interesting read and makes a point of looking at the issues raised when trying to precision match resistors. Apparently it can be done with 0.1% components if you have a lot of them and a multimeter that can measure down to seven decimal places.

[Thanks Bigbob]