nesdev.org

From what I can remember, I did some testing of LY writes at some point (you can probably find the tests with expected output if you snoop around the gambatte repo), and concluded that LY write, in fact, does absolutely nothing.

On the CGB the BG scroll registers are latched per tile, but there is some pipelining or something going on, so the scroll values for a tile are latched some time before it is drawn (around 16 clock cycles IIRC).

I really should get around to properly documenting all my findings on the GBC (and eventually the DMG when I've done more testing). Unfortunately I'm up to my neck in stuff that needs to be done, so for now there's only emulator source code and cryptic test ROMs. Of course, some of it comes down to ...

I share blargg's opinion on this. I tend to implement sound and video on a catch-up basis, and only update status registers when they're accessed. (I do update the cycle counter in the middle of memory opcodes of course.) My event system is almost entirely dedicated to interrupts. Since most or all ...