Interesting: SaveKey

[Deleted]

Did you know the Atari 2600 has a save game dongle? It plugs into the joystick port and games send I2C commands to store and retrieve data.
www.vectrex.biz/MemCard.htm

Since Genesis joysticks can be used on the 2600 I bet it could handle being plugged into a Genesis. I've found no documentation on using I2C devices on the Genesis though. Maybe it's similar to using serial devices?

[Tiido]

You just bitbang the i2c EEPROM or whatever there is. i2c protocol is clearly defined and with a help from datasheet you get things work. µWire and SPI are nicer than i2c.

[Deleted]

I'll try searching on the term "bitbanging" and 68k for more clues on how to control this I2C device from a Genesis controller port. Thanks!

Are there already µWire and SPI eeprom devices that have a Genesis compatible DB9 connection? I guess one advantage to these SaveKey things is that they are already made

[sega16]

All bitbang does is simulate a common protocol using carefully timed bit-wise operations much harder to implant than it is to explain ;D