Yes its was open sourced from the start - sorry just forgot to include the link:
https://github.com/vipoo/rc2014-chip8
At the moment this code only works on a RC2014 kit - but i plan to port it to MSX configuration - so it should be able to be run on MSX emulators and real MSX hardware in the future.
I am currently trying to get Chicken Scratch to run - it requires all the scrolling instructions.
The scrolling proving to be bit of a challenge. When scrolling an individual colour plane, I had to do this in software - which is quite slow. But when scrolling on plane 3 - i can unleash the full power of the hardware acceleration available from the 1980s!