30 lines
1.2 KiB
Markdown
30 lines
1.2 KiB
Markdown
# emu_nes
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A Nintendo Entertainment System (NES) emulator written for the purpose of
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understanding how the NES and similar 8-bit computers of that era worked.
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The NES used a variant of the MOS 6502 8-bit microcontroller called a
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Ricoh 2A03 that contained the 6502 without the BCD mode for arithmetic,
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an audio signal generator (APU), controlling the gamepads, and for DMA.
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([Source: NESdev](https://www.nesdev.org/wiki/DMA))
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A major goal for the emulator is finishing the software implementation
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in C and later implement this in hardware with either an FPGA or another
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CPU like a RISC-V. Later, I want to generalize the 2A03 simulator into
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a full 6502 for use with a Commodore 64 and Apple II.
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Makes heavy use of the [NESdev wiki](https://www.nesdev.org/wiki).
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## Current State
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- [x] CPU (Ricoh 2A03, variant of MOS 6502)
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- [ ] PPU (Graphics)
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- [ ] APU (Audio)
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Currently, running the emulator with nestest.nes results in incorrect
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results in the memory space of the APU registers. This is due to the
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APU not being implemented yet.
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Also, the only ROM mapper that is implemented is Mapper 0 to
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run the test ROM, but it also supports many other ROMs listed
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[here](https://nesdir.github.io/mapper0.html) such as Donkey Kong and
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Super Mario Bros.
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