I posted on assemblergames on how to mod a SG-1000 MK1 and MK2 for composite video!
Those of you who own one and are looking to get better video than RF, feel free to check out my guide
http://assemblergames.com/l/threads/how ... rgb.63383/
Also includes a link for RGB modding a SG-1000 MK2 (5 Rubber feet models only)
From what I've been told there might be an FPGA board solution to adding RGB to Model 1 SG-1000's in the future