philw07 / pich8 Goto Github PK

Spacefight2091! is again broken, because VF is not properly set to 1 when I overflows for CHIP-8 / S-CHIP ROMs.
This behavior is caused by the bigger memory size introduced by XO-CHIP compatibility.
Therefore we must assume CHIP-8 / S-CHIP memory limit unless one of the following is true.

• Loaded ROM size is bigger than available CHIP-8 / S-CHIP memory
• An XO-CHIP only instruction is used

Following this conversation on reddit, it seems the implementation of sprite wrapping is wrong.
Currently, sprites are wrapping even if only partially off screen, whereas the provided sources suggest sprites should only be wrapped if they're completely off screen, otherwise they're clipped.

Since many modern interpreters (including Octo) wrap partially, there might be ROMs out there that rely on partial wrapping, so it might be worth keeping a quirk setting to enable partial wrapping.