Enum PpuRevision 

pub enum PpuRevision {
    Rp2c02H,
    Rp2c02G,
}

v2.1.7 P5 — selectable 2C02 die revision, gating revision-dependent quirks.

Additive and default-off: the Default (Self::Rp2c02H) preserves RustyNES’s established behavior byte-for-byte, so AccuracyCoin, the commercial oracle, and the visual / audio regression suites are unaffected at the default. Only the opt-in Self::Rp2c02G selection changes any emulated behavior (see below).

Real RP2C02 dies shipped across several letter revisions. The one behavioral difference RustyNES currently models per-revision is the OAMADDR ($2003) write-during-rendering OAM corruption glitch: writing $2003 while rendering is enabled on a visible / pre-render scanline copies one 8-byte OAM “row” from row 0 over the row the write’s high bits target, on the next rendered dot (the same CorruptOAM mechanism the rendering-disable model uses; see Ppu::process_oam_corruption). A handful of titles — notably Huge Insect — trip it. It is not enabled on the default revision.

Honesty note (see docs/accuracy-ledger.md): the exact mapping of the $2003 corruption onto specific 2C02 letter revisions is not firmly established in the public literature, and the precise per-title byte output of the glitch is not independently oracle-verified in this cut. RustyNES therefore offers the model as an opt-in approximation keyed to a single “earlier revision” selection (Self::Rp2c02G) rather than claiming exact silicon-revision fidelity. This is config, not save-state: like PpuRegion it is re-applied on load and is not part of the snapshot.

Variants

Rp2c02H

Default. Later RP2C02 die (the “H”-class revision RustyNES has always modeled). The OAMADDR ($2003) write-during-rendering OAM corruption is not modeled, so the deterministic output is byte-identical to a build without this feature.

Rp2c02G

Earlier RP2C02 die (“rev E+” in the nesdev notes). Additionally models the OAMADDR ($2003) write-during-rendering OAM row-corruption glitch that Huge Insect and a few other titles trip. Opt-in; changes emulated behavior only for software that writes $2003 mid-render.

Implementations

impl PpuRevision

pub const fn models_oamaddr_corruption(self) -> bool

Whether this revision models the OAMADDR ($2003) write-during-rendering OAM corruption glitch. Only Self::Rp2c02G does; the default returns false, keeping the default build byte-identical.

Trait Implementations

impl Clone for PpuRevision

fn clone(&self) -> PpuRevision

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PpuRevision

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

Formats the value using the given formatter.

impl Default for PpuRevision

fn default() -> PpuRevision

Returns the “default value” for a type.

impl Hash for PpuRevision

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for PpuRevision

fn eq(&self, other: &PpuRevision) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for PpuRevision

impl Eq for PpuRevision

impl StructuralPartialEq for PpuRevision