Post by bjonte on Aug 17, 2020 15:19:05 GMT
While working on a game I noticed a very important issue with the SuperCPU that needed a workaround.
I had the VIC configured in bank 1 and I configured the SuperCPU to mirror bank 1 to C128 RAM. Then I used a relocated stack to write a sprite to RAM bank 1 under the MMU registers at $ff00. This works when not having a SuperCPU attached but the SuperCPU is tricked by the stack relocation and doesn’t mirror the copied sprite data to the C128 RAM so it acts as if nothing was copied.
One workaround is of course to not do stack relocation writes to bank 1. Another one is to mirror both banks when doing the copy (didn’t try this).
I had the VIC configured in bank 1 and I configured the SuperCPU to mirror bank 1 to C128 RAM. Then I used a relocated stack to write a sprite to RAM bank 1 under the MMU registers at $ff00. This works when not having a SuperCPU attached but the SuperCPU is tricked by the stack relocation and doesn’t mirror the copied sprite data to the C128 RAM so it acts as if nothing was copied.
One workaround is of course to not do stack relocation writes to bank 1. Another one is to mirror both banks when doing the copy (didn’t try this).
