Hey there. I have a rather peculiar problem with this specific mapper. I've expanded my ROM with KingMike's nflate and it somehow throws 256kb of empty space to the beginning of the ROM just after the header. The question is: how the heck can I calculate bank indexes for switching, if the text starts much further on and it starts with bank index 1?
The whole bank index writing procedure involves 3 indexes (6 banks are emulated as 3 here, as they are switched in pairs). The bank index writing routine looks like this:
I understand, this is a special case (as KingMike explained in his readme) but how can I use the free space I obtained?

It's Dream Master and yeah, it runs perfectly. Expansion was from 512 and up to 768kb but we were somehow confused about the way it expanded PRG. And it has the same number of banks as Kaijuu, as I see - from 00 to 0f - but the thing is that all the empty space after expansion was BEFORE the original banks. I mean, header, empty space, original banks with text I want to swap. So if text is somewhere in 50xxx inside the rom, empty chunk begins somewhere at 11-12, then 32xxx and so on. It uses only 3 doubled banks for dialogue text - (2x8kb per each) and it does seem to use direct values. we need to dig in, I guess - thanks for the hint!

UPDATE: Ok, for those interested, the game starts indexing new-formed bank from 10 and further on, starting from the the address 10 where the first new bank starts. So generally, indexing goes as follows inside the rom: 10, 11...1f, 00, 01...0f.

Hmm... It's quite strange 'cause after nflate expansion it seems to work without any problem... But the banks now start with 10,11... then go original 00,01 banks. And the tile map seems to be ok as well... At the moment I only have some problems with moving the text there (I need to make custom pointers) but the text is easily read from new banks. The only peculiarity is that the banks here are seen as 4000 by the program as it switches 'em in pairs...