Zerd no Densetsu (Japan) crashes out on the very first screen

[benderscruffy]

[wwark]

Some information for this game that only work on Gameboy. (Original Gameboy Color hangs on this game)

https://mgba.io/2017/05/29/holy-grail-bugs/#stat-irq-glitches

"The second glitch only occurs on the Game Boy, not on the Game Boy Color. When writing to the STAT register there are actually circumstances in which an interrupt will spuriously trigger without any of the STAT IRQ conditions being fulfilled. As with seemingly all obscure hardware bugs there are games that rely on this bug as well. A commonly cited game is Legend of Zerd (ザードの伝説, also known as Legend of Xerd or Zerd no Densetsu), which immediately crashes if the bug is not emulated. Likewise, the game will not run on a Game Boy Color since the bug was fixed."

[drhelius]

Thanks! Yes, I’ve known how to fix the LCD STAT IRQ for a long time, see #158.

The challenge here is that it’s tricky, and if it’s not done correctly it can break many other games.

I’ll implement it eventually, though.