![Wink ;-)](./images/smilies/icon_wink.gif)
In an emulator, I found that the best way to handle SRAM in an automatical way (but certainly not accurate) is to handle all writes above ROM size area as SRAM writes (some games use 300000h and above, I also found a 4MB korean game which uses the 400000h-40FFFFh area) and emulate the "official" mapper at A130F1h by default (for the few games having ROM & SRAM mapped in the same area)
I also wonder if it's possible to have SRAM mapped under 200000h and access it: doesn't it need some particular asserted signals ?