Initial D Gaiden (Japan) (SGB Enhanced).gb flashing lines during gameplay

[jsgroth]

I'm not able to test this on actual hardware at the moment, but this might be the game's programming. It relies on lots of mid-frame SCX writes to render the road and it will skip some of those writes if the timer interrupt triggers at specific points in the middle of its STAT interrupt handler. Forcibly disabling the timer interrupt eliminates a lot of the glitchy lines but breaks the music outside of gameplay.

Comparing to a few other emulators:

• SameBoy and Gambatte - Very similar behavior, although it's less noticeable in SameBoy because it emulates LCD motion blur
• Emulicious - Significant graphical corruption and the game runs too slow
• ~bgb - Doesn't boot~

[jsgroth]

Correction, I thought it was failing to boot in bgb but it was actually just taking a long time to initialize the SGB border. The game works in bgb and behaves similarly to how it does in SameBoy/Gambatte, lots of flickering lines.