Remove nes implementation so that we can implement it in a better way from scratch.

2026-08-27 00:04:59 +02:00
parent 60a6364625
commit 425ebe0938
47 changed files with 0 additions and 7116 deletions
@@ -1,157 +0,0 @@
-const Cartridge = @import("cartridge.zig");
-
-const Controller = @import("controller.zig");
-
-const Ppu = @import("ppu.zig");
-
-const Apu = @import("apu.zig");
-
-const Bus = @This();
-
-ram: [0x800]u8 =
-    [_]u8{0} ** 0x800,
-
-cartridge: Cartridge,
-
-ppu: Ppu = .{},
-apu: Apu = .{},
-
-controllers: [2]Controller = .{
-    .{},
-    .{},
-},
-
-open_bus: u8 = 0,
-
-oam_dma_page: ?u8 = null,
-
-pub fn init(
-    rom: []const u8,
-) Cartridge.Error!Bus {
-    return .{
-        .cartridge = try Cartridge.init(rom),
-    };
-}
-
-pub fn reset(
-    self: *Bus,
-) void {
-    self.ppu.reset();
-    self.apu.reset();
-
-    for (&self.controllers) |*controller|
-        controller.reset();
-
-    self.oam_dma_page = null;
-}
-
-pub inline fn read(
-    self: *Bus,
-    address: u16,
-) u8 {
-    const value: u8 = switch (address) {
-        // 2 KiB internal RAM + mirrors.
-        0x0000...0x1fff => self.ram[address & 0x07ff],
-
-        // PPU registers + mirrors.
-        0x2000...0x3fff => self.ppu.cpuRead(
-            &self.cartridge,
-            address & 7,
-        ),
-
-        // APU status.
-        0x4015 => self.apu.readStatus(),
-
-        // Controller 1.
-        0x4016 => self.controllers[0].read(),
-
-        // Controller 2.
-        0x4017 => self.controllers[1].read(),
-
-        // Cartridge space.
-        0x4020...0xffff => self.cartridge.cpuRead(address),
-
-        else => self.open_bus,
-    };
-
-    self.open_bus = value;
-
-    return value;
-}
-
-pub inline fn write(
-    self: *Bus,
-    address: u16,
-    value: u8,
-) void {
-    self.open_bus = value;
-
-    switch (address) {
-        0x0000...0x1fff => self.ram[address & 0x07ff] =
-            value,
-
-        0x2000...0x3fff => self.ppu.cpuWrite(
-            &self.cartridge,
-            address & 7,
-            value,
-        ),
-
-        0x4000...0x4013 => self.apu.write(
-            address,
-            value,
-        ),
-
-        // OAMDMA
-        0x4014 => self.oam_dma_page = value,
-
-        0x4015 => self.apu.writeStatus(value),
-
-        0x4016 => {
-            self.controllers[0].write(value);
-            self.controllers[1].write(value);
-        },
-
-        0x4017 => self.apu.writeFrameCounter(value),
-
-        else => self.cartridge.cpuWrite(
-            address,
-            value,
-        ),
-    }
-}
-
-/// Called exactly once for every CPU cycle.
-pub inline fn tick(
-    self: *Bus,
-) void {
-    self.apu.tick();
-
-    // NTSC NES: PPU runs at 3× CPU clock.
-    self.ppu.tick(&self.cartridge);
-    self.ppu.tick(&self.cartridge);
-    self.ppu.tick(&self.cartridge);
-}
-
-pub fn nmiLine(
-    self: *Bus,
-) bool {
-    return self.ppu.nmiAsserted();
-}
-
-pub fn irqLine(
-    self: *Bus,
-) bool {
-    return self.apu.irqAsserted() or
-        self.cartridge.irqAsserted();
-}
-
-pub fn takeOamDmaPage(
-    self: *Bus,
-) ?u8 {
-    const page =
-        self.oam_dma_page;
-
-    self.oam_dma_page = null;
-
-    return page;
-}