Gamebuino forum

I'm working on a project that involves I2C and I would like to know what speed Gamebuino uses. I'm interfacing it with an Arduino Zero.

Hey,
The Gamebuino is based on Arduino Uno, so it uses it's default 100kHz.

They explain in this Arduino forum post how to increase it to 400kHz, but I doubt it's really necessary.
The advantage of I2C is that you can have many slaves with no extra pins thank to the adresses system. But if you want more speed, you can use the SPI bus (talking about MEGA hertz here, wow!) which is accessible though the 6 pin ISP port on the left of the Gamebuino. Beware, as this bus is shared between the screen and the micro SD, don't leave your slave enabled when not communicating, or it will interfere. You can use the pins from the I2C as outputs to drive the chip select pin of your slave.

I need both multiplayer and the Arduino Zero on I2C. How could I achieve that? As the SPI data transfer will be handled by DMA and not the CPU of Zero, how am I supposed to stop the SPI transfer over I2C without the CPU intervening. The CPU will probably be busy with rendering the TV output.

P.S. I'm working on a "pseudo-graphics card" for Gamebuino that would give the games better graphics.