2018-10-25 13:02:27 +00:00
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# mos6502
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[](https://travis-ci.org/mre/mos6502)
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2017-10-08 15:31:20 +00:00
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2018-11-04 20:39:15 +00:00
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An emulator for the [MOS 6502 CPU](https://en.wikipedia.org/wiki/MOS_Technology_6502) written in Rust.
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2018-11-04 20:54:09 +00:00
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This started off as a fork of [amw-zero/6502-rs](https://github.com/amw-zero/6502-rs),
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2017-10-08 15:31:20 +00:00
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which seems to be unmaintained at this point.
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2018-11-04 19:40:00 +00:00
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It builds with the latest stable Rust and supports `#[no_std]` targets.
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2018-11-04 19:26:51 +00:00
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## Usage example
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```rust
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extern crate mos6502;
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use mos6502::cpu;
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use mos6502::address::Address;
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fn main() {
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let mut cpu = cpu::CPU::new();
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let zero_page_data = [
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// ZeroPage data start
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0x00,
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0x02, // ADC ZeroPage target
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0x00,
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0x04, // ADC ZeroPageX target
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0x00,
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0x00,
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0x00,
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0x00,
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0x10, // ADC IndexedIndirectX address
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0x80, // ADC IndexedIndirectX address
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0x00,
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0x00,
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0x00,
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0x00,
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0x00,
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0x08, // ADC IndirectIndexedY address
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0x80, // ADC IndirectIndexedY address
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];
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let program = [
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// Code start
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0xA9, // LDA Immediate
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0x01, // Immediate operand
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0x69, // ADC Immediate
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0x07, // Immediate operand
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0x65, // ADC ZeroPage
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0x01, // ZeroPage operand
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0xA2, // LDX Immediate
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0x01, // Immediate operand
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0x75, // ADC ZeroPageX
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0x02, // ZeroPageX operand
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0x6D, // ADC Absolute
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0x01, // Absolute operand
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0x80, // Absolute operand
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0xA2, // LDX immediate
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0x08, // Immediate operand
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0x7D, // ADC AbsoluteX
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0x00, // AbsoluteX operand
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0x80, // AbsoluteX operand
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0xA0, // LDY immediate
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0x04, // Immediate operand
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0x79, // ADC AbsoluteY
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0x00, // AbsoluteY operand
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0x80, // AbsoluteY operand
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0xA2, // LDX immediate
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0x05, // Immediate operand
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0x61, // ADC IndexedIndirectX
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0x03, // IndexedIndirectX operand
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0xA0, // LDY immediate
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0x10, // Immediate operand
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0x71, // ADC IndirectIndexedY
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0x0F, // IndirectIndexedY operand
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0xEA, // NOP :)
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0xFF, // Something invalid -- the end!
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];
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let data: [u8; 25] = [
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0x00,
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0x09, // ADC Absolute target
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0x00,
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0x00,
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0x40, // ADC AbsoluteY target
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0x00,
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0x00,
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0x00,
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0x11, // ADC AbsoluteX target
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0x00,
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0x00,
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0x00,
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0x00,
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0x00,
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0x00,
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0x00,
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0x12, // ADC IndexedIndirectX target
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0x00,
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0x00,
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0x00,
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0x00,
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0x00,
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0x00,
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0x00,
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0x06, // ADC IndirectIndexedY target
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];
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// "Load" a program
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cpu.memory.set_bytes(Address(0x0000), &zero_page_data);
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cpu.memory.set_bytes(Address(0x4000), &program);
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cpu.memory.set_bytes(Address(0x8000), &data);
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cpu.registers.program_counter = Address(0x4000);
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cpu.run();
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}
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```
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