wondering how smb3 would look like on msx1

Huey you forgot my game objects have 2 colors each.

Mario = 8 (16x32 + 16x16 for tail + 16x16 when grabing a shell)
Fireballs = 3 x 2 (16x16)
Powerup= 2 (16x16)
NPCs = 4 x 4 (16x32)

So I can't have more than 1 powerup, more than 3 fireballs and more than 4 enemies on screen. the Bowser should take 2 NPCs slots.
For the ship I can have up to 9 cannon balls since there is plants there and I can borrow plant's fireball.

The slots have fixed positions, so this make the animation sets a lot easier. Mario has an updside down T shape.

>>with 32 sprites on a row you need 8 frames to display all. looks horrible.

what about a pseudo-random order, scrambling the SAT instead of ring buffering it ?

Interesting technique. I'll try this as my patterns do not overlap themselves. This makes the copy little slower as extra logic is inserted.

I have fixed pattern slots, not fixed SAT slots. It's a new concept (i suppose). But you are right, I could end up having holes in the sat, but I can move them to the end of the SAT without any problem and avoid flicking them. In the demo I have 24 used sprites, so 8 holes are flicking around.
how can I do it ? Simple, I have 2 SAT tables in RAM, those sats are double buffered, i update the off-screen SAT always, synchronizing with the interrupt. Those RAM SATs they have fixed slots. But the interrupt will copy the SAT to VRAM ringing it every 1/60s. (i can add a check for the 5th sprite). So the interrupt will selectively flick only the used slots or use any different algorithm.

Right now I rotate the entire SAT 4 sprites left every vsync. Why do I have a SAT in ram ? because the code updates the RAM SAT 0 which is always mario. But the interrupt will take the RAM SAT 0 and copy to VRAM shifting it left every vsync. So I don't care what position is the mario SAT in VRAM (there is only one mario in VRAM, all the SAT is copied but rotated), I always use RAM instead. And why 2 SATS ? Because I use a lot of sprites, I don't want to disable interrupts when updating several sprites, or allow sprites to tear because an interrupt occurred between the update, so I update the second buffer then I flush it at the end. When I flush the interrupt will look for the second buffer and leave the first for me to update. This forces me to update all positions to the current buffer but it's ok.
The same thing I do for patterns. I have the sprite pattern 0 and 32 for the first sat position, 1 and 33 for second and so on. When I need to update a pattern I take the pattern that is not being displayed. And the new pattern will be displayed only when I flush the SAT.
If I need to use more than 32 sprites I will need to share the same pattern, but this is not the ideal for my engine, as patterns flips, can receive special effects like scissors (when mario is going down a pipe), etc.