I just have been making so much progress. But now I am VERY stuck. When I download the "firmdl.bat" file to the RCX, it climbs up to 67%, then fails. Here is the error:
"Response = -4"
I have researched, but cannot find what this means. I have tried replacing batteries, changing amount of ambient light, etc. No solution yet. I would really appreciate any answers to this problem, thanks.