Thanks for the feedback :-)
I know the VDP emulation is not perfect yet. Also sprites which should be partially visible on the left and right side on the screen are now not rendered at all, and the 4 sprites/line limit is not emulated. And you're right about the sound as well, there seems to be a problem in the PSG emulation (noise is missing sometimes).
I have to start supporting all keys in the emulator framework (was not necessary with arcade only emulation) so that I can properly support the MSX keyboard.

Other than that, was the speed correct?
On my home PC, it seems to run too fast under some java versions (1.5 and 1.6) although the FPS counter (F9) says 50FPS. But that PC seems dodgy atm anyway, so maybe I'm the only one experiencing that...

Speed seemed to be OK, I think. I'm using java version "1.5.0_05"

Just a status update.
I started trying to get smooth scrolling in SkyJaguar. I found that memory address 0xe322 can be translated to a pixel offset for the scroll field. Well, sort of...
It mostly scroll smoothly now but sometimes it starts jerking around, most of the times when enemies start flying in the screen (but not always). It seems that the background scrolling speed is not really constant, as if when some enemies appear the cpu can't keep up or something and the scrolling gets delayed. I tried raising the Z80 clock speed but this didn't help at all.
Maybe 0xe322 is not correct, or maybe I need to keep track of when the background start scrolling 8, and wait for that to happen until I update the pixel offset when it is at an offset of 7.
Any other ideas are welcome :-)
All in all, it seems more difficult than I hoped...

Oh, and I've been playing around with the idea to implement the 4 sprites on one line limit but in a way that it will only do that when 'wanted', i.e. that there will be no flickering but some effects that may use this will still work (like the effect when entering a door in MoG or falling in the water in Athletic Land).
Maybe this is possible by only counting the sprites/line when 4 sprites have the same coordinates and patterns. This of course assumes that this is usually how the developers create the effect like in MoG.