Its looking great I notice the screen take a while to refresh, and it like does a scanline as it renders the next screen.  Is this intentional?  Since i think it can be removed with clever use of updating buffers.

I can't seem to hear the music lagging, but that might have to do with the scanline problem as well, because the DispGraph^rr is in the interrupt now to increase quality. The scanline thing is because before each row is drawn, the interrupt is turned off, then turned on once the row is finished. I'll have to see about getting around that.

This is very nice

Or you could just disable them before the entire screen and then re enable them only after everything has been drawn maybe?

That could work if there was one screen update per interrupt, but there is probably a counter. So during the time that the interrupts are disabled, it will miss some counts.

Looks much better, although it still isnt updating all at once is it?  Still, great improvement fro  my view

The flickering is probably a by-product of the horrible LCD, but while standing still the grey is almost perfect.

@Builderboy: It still doesn't update all at once, instead it updates every two rows. It's much less noticeable, on-calc or emulated, and once I fix the music lag, then I think I can call this pretty much done.

Still working on the music lag, but I did manage to have it draw a black tile whenever part of the map is out of bounds.

Nice!