Jagosaurus wrote:So you need the M3/GG converter, then a M3 to SMS pinout converter. Interesting.
If you're going to use the RF's 3-in-1 adapter to play SMS games via that top slot, yes.
Something like this would work,

Of course, that's not the only way to play SMS games on the RetroFreak. You could eliminate that 3-in-1 adapter from the equation altogether.
Again, I was just pointing out another way in which it could be done.
FYI, other options (but not limited to) for SMS games:

Just to add,
you don't need a Mark III to SMS converter with the Retron 5's own 3-in-1 adapter. That top slot is designed for SMS carts.
Does it support SMS ROMS off SD w/o any of this?
Haven't tried it. It could well do.