Managed to get the RC2014 SIO/2 Board to work with my MSX rig.
Its took a bit of finessing to get the higher baud rate (57200) working with MSX BIOS interrupt handler - the overheads make it easy to lose data.
The application talks directly to the SIO chip. A future goal will be to integrate the serial driver within the BIOS/Nextor systems.
After a few bodge fixes - i was able to get the sound board working (YM2149 chip). I considered using the RC2014 Sound board, but I don't think the revision I have supports the MSX ports. A later revision seems to.
The board I designed, also support controller ports -- if only I owned a MSX controller!
(The missing chips are required for the controller ports - will install when i get an MSX controller to test with)
In the next few days, I will try and get myself organised, and upload designs.
In the meantime you can watch me playing PACMAN really badly.