The JTSIMSON core has been updated to include the 1990 arcade game, which was known as Parodius da! in Japan and Parodius! From Myth to Laughter elsewhere in the world.
It is the second game in the Parodius series and would be ported to the NES, SNES, Game Boy, PC Engine, PlayStation, Sega Saturn and X68000, with the European SNES, Saturn and PlayStation ports being named Parodius: Non-Sense Fantasy.
The Parodius series is a parody of Konami's own Gradius franchise and includes similar gameplay mechanics.
Here's the detail from JOTEGO's latest Patreon update:
We worked on Parodius da! schematics last year. It turned out to be very similar to The Simpsons board, with some differences:
+ Different sprite chipset: 053244/5 instead of 053246/7. This chipset is very similar but only supports half the sprite count of the Simpsons one. Sprite scaling uses a different range and there are some small changes in what configuration bits mean that brought a bigger headache than expected...
+ Sprite shading disabled (devices not soldered on the board)
+ Differences in device memory mapping
I have extended JTSIMSON to support this board. The game seems fully playable although I have only tested the first two levels. You will notice some broken sprites due to the sprite scale range not being fully implemented yet.
This game also uses an unknown CPU instruction. This is the Konami CPU for which not everything is known yet. We are kind of bypassing that instruction and the game seems to run ok. We want to experiment with the original hardware to derive the instruction meaning and correctly implement it.
You'll need to be signed up to JOTEGO's Patreon account to be able to play this.