Struct Cartridge 

#[non_exhaustive]
pub struct Cartridge {

    pub prg_rom: Box<[u8]>,
    pub chr_rom: Box<[u8]>,
    pub mapper_id: u16,
    pub submapper: u8,
    pub mirroring: Mirroring,
    pub region: Region,
    pub console_type: ConsoleType,
    pub vs_ppu_type: VsPpuType,
    pub vs_dual_system: bool,
    pub prg_ram_size: u32,
    pub chr_ram_size: u32,
    pub has_battery: bool,
    pub has_trainer: bool,
    pub is_nes2: bool,
    pub nametable_wiring_bits: u8,
}

Concrete iNES / NES 2.0 cartridge value.

prg_rom and chr_rom are read-only ROM banks. prg_ram_size and chr_ram_size are requested sizes; mapper implementations allocate the matching RAM buffers in their constructors.

Field set follows docs/cartridge-format.md §Public API. mapper (the boxed dyn Mapper from docs/mappers.md) is constructed by crate::parse and stored on the cartridge separately from this metadata header so the metadata is cheap to clone.

#[non_exhaustive] since v3.0.0 (T-API-EXTENSIBLE): outside this crate a cartridge comes from crate::parse (or the other loaders), or from Cartridge::synthetic for a device with no cartridge header; set the public fields that differ afterwards. A later header field is then not a break, as nametable_wiring_bits was at v2.9.9.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

prg_rom: Box<[u8]>

PRG-ROM bytes. Length is a multiple of 16 KiB for standard sizes; may be irregular when the NES 2.0 exponent-multiplier encoding is used.

chr_rom: Box<[u8]>

CHR-ROM bytes. Empty when the cartridge uses CHR-RAM (length 0).

mapper_id: u16

12-bit mapper id (iNES 1.0 only uses the low 8 bits).

submapper: u8

4-bit submapper id (NES 2.0 only; always 0 for iNES 1.0).

mirroring: Mirroring

Initial mirroring as selected by the header.

region: Region

Region from NES 2.0 byte 12; defaults to Region::Ntsc for iNES 1.0.

console_type: ConsoleType

Console type from NES 2.0 byte 7; always ConsoleType::Nes for iNES 1.0.

vs_ppu_type: VsPpuType

Vs. System PPU type from NES 2.0 byte 13 (low nibble), valid only when console_type == ConsoleType::VsSystem; VsPpuType::None otherwise.

vs_dual_system: bool

True when the header marks a Vs. DualSystem board (NES 2.0 byte-13 high nibble = Vs. hardware type 5/6). Detection only; the two-CPU/two-PPU emulation is a documented v2.0 deferral.

prg_ram_size: u32

Requested PRG-RAM size in bytes.

chr_ram_size: u32

Requested CHR-RAM size in bytes (0 if the cart ships with CHR-ROM only).

has_battery: bool

True if the cartridge has non-volatile save data: battery-backed PRG-RAM per the header, or (v2.9.6) a self-flashable board’s flash (mappers 30 and 111), set by the loader whatever the header’s bit says.

has_trainer: bool

True if a 512-byte trainer was present in the file (loaded at $7000-$71FF).

is_nes2: bool

True if the file format is NES 2.0 (vs. iNES 1.0).

nametable_wiring_bits: u8

The raw iNES byte-6 nametable bits, byte6 & 0x09 (bit 3 four-screen, bit 0 the arrangement bit), before Self::mirroring folds them. Mappers 30 (UNROM 512) and 218 (Magic Floor) wire CIRAM from these bits directly, so two headers that both say FourScreen can build different machines; v2.9.9 carries the bits so the movie and netplay board check can tell them apart (core re-audit NC-10). Zero for formats without an iNES header (FDS, NSF).

Implementations

impl Cartridge

pub fn synthetic(mapper_id: u16, prg_ram_size: u32, chr_ram_size: u32) -> Self

v3.0.0 — metadata for a machine whose program does not come from a cartridge header (the FDS, an NSF player): empty PRG/CHR-ROM, NTSC, horizontal mirroring, a stock NES, no battery, trainer or NES 2.0 header, and the given mapper id and RAM sizes. The bus consults little of it for such a machine; the device owns its own storage. Set any field that differs after construction.

pub fn uses_chr_ram(&self) -> bool

Returns true when this cartridge ships PRG-ROM only (no CHR-ROM bank).

Trait Implementations

impl Clone for Cartridge

fn clone(&self) -> Cartridge

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Cartridge

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.