What is a Copper Chunky2Planar?

[DamageX]

As i understand with a copper c2p routine you have also all bitplanes to make more stuff.

You can't use bitplanes on the same lines as copper chunky modes because bitplanes would prevent the copper from copying pixels at full speed.

[DamageX]

Walls1.7 takes advantage of this by displaying 3 bitplanes of screen images overlapping the copper chunky backdrop.

It doesn't look to me like a copper chunky backdrop, just a copper "rainbow"

Any more than 3 bitplanes on the ECS chips will cause the blitter to steal DMA channels from the copper and ruin the copper-chunky effect.

Uh oh, now I'm confused. I don't see how this could be possible. How many memory accesses are needed for each copper chunky pixel? One instruction and one data? Or can the copper have one instruction followed by a whole line worth of data? Does copper list DMA have priority over CPU access to chipmem?