Found the problem with it,I tried every possible thing on Earth with it and finally the simplest solution pops up: it seems that the protection jump at $f03c0 a.k.a. the palette ram sub-routine is called with the wrong vector.Differences between this call and all the others is that the D2 register is not equal to zero but is equal to 0x0b00000.My 0,50 € guess is that the programmers added this extra “feature” to protect the most interesting thing of this game. 😛

Now I need to check the other two girls and if there’s consistency I have to add this to the sub-routine…

Fixed the bankswitch bug in Urashima Mahjong.It uses a ram location at $8001c and some combinations between the two bg roms.

 I hate to say but it happens that when a problem is fixed another one pops up.Needs to know why when you win the colors are screwed up like this:

Color bankswitching?

As I’ve expected previously,this game simply uses different addresses for the video ram and two planes instead of four.It appears to be an earliest revision than the other games of this hardware,namely:

urashima -> daireika/mjzoomin -> kakumei/kakumei2 -> suchipi

Needless to say,the game now “somewhat” works.Still to do: fix/find the tile banking (as you can see in snap 4) and double check the scrolling registers.

Got a look into the jalmah.c driver again,fixed a regression which caused an hang bug into daireika,mjzoomin and urashima and fixed a protection issue with the random number generator into Mahjong Daireikai.Game now fully playable with some annoying video issues here and there.

Next episode only on this channel: get Urashima Mahjong to work.

Well,got some new ST-V games to boot thanks to a better understanding of the IC13 rom loading:

Find Love

Suikoenbu

Sokyugurentai / Terra Diver

Now the bad news:none of these three games are really playable for a reason or another,but I’m still investigating on it…