// GNROM (mapper 66) demo — 32 KB PRG page + 8 KB CHR bank in a // single write to `$8000-$FFFF`. Bits 4-5 select the PRG page, // bits 0-1 select the CHR bank. Single-page GNROM is functionally // equivalent to AxROM at the PRG level; this example just exercises // the reset-time init and iNES header emission. game "GNROM Demo" { mapper: GNROM } 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