DIY Master system converter


New Member
Hi people.

In the past couple of weeks I've been building a Master System converter to be able to play Master System games on my Genesis.
It works like a charm and every game I fire at it works.
The bios stack thing is simulated by an AVR.

I've also build a flashrom cartridge with a 315-5235 mapper chip so I can flash and play games up to 512K on there.

As reference material a friend of mine send me his spare master system 2 so I could compare signals of my bios stack AVR to the behavior of the real master system.

Main reason for starting this project is that I had an SMS2, but the I/O & Timer chip died so I couldn't play my master system games anymore.