v9990 coding....

msd: BMLL is not as usefull as BMXL. BMLL can be replaced by LMMM in most cases (without any speed difference).

manuel: Setting bit 7 of reg#8 during display period will not keep the vdp from displaying.
Writing to r#17 or r#21 will make the vdp continue to display from that line. And writing to high parts (r#18 and r#22) will again be ignored until vblank.

When you fix those thing I can stop using my 'Dragon Engine' for v9990 emulation (or even the real thing).

manuel: Setting bit 7 of reg#8 during display period will not keep the vdp from displaying.
Writing to r#17 or r#21 will make the vdp continue to display from that line. And writing to high parts (r#18 and r#22) will again be ignored until vblank.

GhostwriterP: I fixed this in openMSX. I hope it's useable for you now.
BTW what is this 'Dragon Engine' you're talking about?

GhostwriterP: interesting. Is it available somewhere? Preferably the source code. I'm sure there is other useful info in there to improve the V9990 emulation in openMSX. Or even in general it can be useful for other emulator developers.