Outrun style road demo MSX2

I don't know for the current version ... I think the last time I checked it was around 10 fps.
The result looks good, that's all I know.

It's a joint work between the V9938 and the Z80.
The VDP provides the blitter engine for main rectangle areas.
The Z80 calculates and outs the rest.

That is my intention.

But I'm cautious, and for 2 reasons :

• The framerate is OK for now, but there's only the road rendering engine and it's already making intensive use of CPU and VDP. If I add multiple sprites (and I will need all 32 of them, maybe even use spritesplit to add some more), score, music, background, it might slow down things too much to be playable. That's why I'm going one step at a time.
• I know myself. I tend not to finish things. So far, I must say that it's been the MSX project on which I have worked the longest (5 months), but I know life tends to interfere at some point ...

Awesome! I think back in 1996 i could lift such optimization myself (i remember i was hunting each CPU cycle), and now i see i was too linear with my routine and therefore dumb, maybe decades of not programming assembler made those skills quite rusty. Thanks, i'm gonna use your snippet, it have a nice low overhead

Can't your engine skip frames?,if so you can leave free a lot of time and increase the speed feeling.

Obviously, but how much of the current FPS is due to the VDP? Would things get much smoother with a fast VDP such as the G9k? I'm just trying to find out if there's an MSX configuration that would run this smoothly, with music, sprites and perhaps some objects passing by, background mountains etc. What would e.g. the performance be with a tR/R800 + g9k?

If I disable the part of the rendering done by the Z80, I gain 25% of the total cycles needed to built a full frame. But you have to keep in mind that the Z80 is rendering during the VDP HMMV commands. Therefore, a big part of the Z80 cycles are absorbed.