ADD SUB Flag
From SnesLab
The ADD SUB Flag is bit 7 of CGADSUB (2131h).
When set, the Main Screen and Sub Screen are added together. When clear, the Sub Screen is subtracted from the Main Screen.
The ADD SUB Flag is bit 7 of CGADSUB (2131h).
When set, the Main Screen and Sub Screen are added together. When clear, the Sub Screen is subtracted from the Main Screen.