Everything is pin for pin except pin 22 - that's a secondary (active high) chip select on the uDP43257 that Sega used and an (active low) output enable signal on the FRAM. Since CE/ controls the outputs too, you can just lift pin 22 and wire the pin to ground.
You can't change the region on the fly without a reset because the jumpers are only read on reset - you can switch video mode without a reset (so make sure that the switchless mod you are using allows you to change video mode without changing region). I personally found that a combination of the region-free boot ROM and a soft 50/60Hz switch worked better for me.
crystal clear as always mr. Trimesh
I'll ground pin 22 of the fram to the nearest ground point
However there are three questions still remaining about region & frequency:
1)Let's say I have my switchless mod set to PAL 50, put in a PAL game and then while playing the game I long press the reset button and change to NTSC-US. Will the game crash? Or will it just change to 60 Hz and play normally?
2)Let's say I change my switchless mod to NTSC-US and then reset the console to keep this setting active. Will a NTSC-US game boot normally (without needing a region-free bios)?
3)Will NTSC-US and NTSC-J games run properly on a PAL console in general, or is the PAL saturn crystal not producing the correct frequency and these games play a bit more slowly?
Edit:
I think I found the answers to 1) and 2) in
https://knzl.at/saturnmod/ , which is written by Seb, the original author of the switchless mod.
1)long pressing less than 1,25 sec on the fly will only change the frequency (50/60 Hz) and not the region
2)Yes Ntsc-us and ntsc-j discs will work fine with the switchless mod only - no need for region free bios!
So my preferred mod combo will be phantom + FRAM + switchless mod + battery in place.
But question 3) is still unanswered... do I also need a dfo mod, and how do I combine it with the switchless mod?