Gerard Gascón
The video card uses a 4kB dual port SRAM, a 25.175MHz oscillator downclocked to 6.29375MHz by a counter and has been tested using an Arduino Mega. In this version I generate an image with the size of 160x120px (An eighth part of 640x480).
Make your own
If you want to build it yourself, I've left some scripts for image conversion and SRAM communication via Arduino. The build process is very similar to Ben Eater's version, except for the VGA timings and memory read process.
For more details, you can find all the schematics below.
Extending it
The reason I made this project is to find an alternative to Ben Eater's implementation with the 6502. In this case my solution should be much more performant than his version as this one doesn't depend on halting the CPU during the screen refresh process.
Another thing that could be done would be to get more colors, it shouldn't be hard, the only problem is that in this project I didn't want to print a PCB, I wanted to do that in breadboards, so the SRAM had to be small because larger models use other packages that aren't DIP.
For higher resolution, the problem would be the same, I will need a PCB in order to keep the dual port SRAM in the circuit.
If you try to expand this circuit, I'd love to hear how it goes!
Ian Hanschen
Jon Thomasson
rossumur
danielbn