// CNROM (mapper 3) demo — fixed 32 KB PRG, switchable 8 KB CHR. // Single-bank CNROM exercises the mapper reset, header emission, // and compatible runtime — functionally equivalent to NROM but // with a different iNES mapper number. game "CNROM Demo" { mapper: CNROM } var px: u8 = 120 var dx: u8 = 1 on frame { if dx == 1 { px += 1 if px >= 240 { dx = 0 } } else { px -= 1 if px == 0 { dx = 1 } } draw Ball at: (px, 100) } start Main