Neville, I'm glad you like that. Let me tell you about the funny story that lead to these being emulated.
The other day I set out to emulate the JyCompany mapper for Dragon Ball Z Super B. 2. - it was needed to get the English translation to work, since the translation patch only worked on the original cart rom.
After finishing up the mapper, I give the game a try and it didn't start, mapper91 not implimented..
By some stupid mistake (PSA:I make a lot of them), I ended up emulating mapper 90 (Jy Company), which took many, many hours.
The game really needed mapper 91 (Older Jy Company/Hummer team), which is a simple mapper that took under 20 minutes to complete.
derp! On the other hand, its nice to have this extra mapper.
best regards,
- dink