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Merge pull request #21 from GooseDB/update-readme 

Updated readme: euclidean_algo example
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Matthias Endler 2019-10-22 19:55:35 +02:00 committed by GitHub
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@ -13,106 +13,44 @@ It builds with the latest stable Rust and supports `#[no_std]` targets.
```rust
extern crate mos6502;
use mos6502::cpu;
use mos6502::address::Address;
use mos6502::cpu;
fn main() {
let mut cpu = cpu::CPU::new();
let zero_page_data = [
// ZeroPage data start
0x00,
0x02, // ADC ZeroPage target
0x00,
0x04, // ADC ZeroPageX target
0x00,
0x00,
0x00,
0x00,
0x10, // ADC IndexedIndirectX address
0x80, // ADC IndexedIndirectX address
0x00,
0x00,
0x00,
0x00,
0x00,
0x08, // ADC IndirectIndexedY address
0x80, // ADC IndirectIndexedY address
];
let zero_page_data = [56, 49];
let program = [
// Code start
0xA9, // LDA Immediate
0x01, // Immediate operand
0x69, // ADC Immediate
0x07, // Immediate operand
0x65, // ADC ZeroPage
0x01, // ZeroPage operand
0xA2, // LDX Immediate
0x01, // Immediate operand
0x75, // ADC ZeroPageX
0x02, // ZeroPageX operand
0x6D, // ADC Absolute
0x01, // Absolute operand
0x80, // Absolute operand
0xA2, // LDX immediate
0x08, // Immediate operand
0x7D, // ADC AbsoluteX
0x00, // AbsoluteX operand
0x80, // AbsoluteX operand
0xA0, // LDY immediate
0x04, // Immediate operand
0x79, // ADC AbsoluteY
0x00, // AbsoluteY operand
0x80, // AbsoluteY operand
0xA2, // LDX immediate
0x05, // Immediate operand
0x61, // ADC IndexedIndirectX
0x03, // IndexedIndirectX operand
0xA0, // LDY immediate
0x10, // Immediate operand
0x71, // ADC IndirectIndexedY
0x0F, // IndirectIndexedY operand
0xEA, // NOP :)
0xFF, // Something invalid -- the end!
// (F)irst | (S)econd
// .algo
0xa5, 0x00, // Load from F to A
// .algo_
0x38, // Set carry flag
0xe5, 0x01, // Substract S from number in A (from F)
0xf0, 0x07, // Jump to .end if diff is zero
0x30, 0x08, // Jump to .swap if diff is negative
0x85, 0x00, // Load A to F
0x4c, 0x12, 0x00, // Jump to .algo_
// .end
0xa5, 0x00, // Load from S to A
0xff,
// .swap
0xa6, 0x00, // load F to X
0xa4, 0x01, // load S to Y
0x86, 0x01, // Store X to F
0x84, 0x00, // Store Y to S
0x4c, 0x10, 0x00, // Jump to .algo
];
let data: [u8; 25] = [
0x00,
0x09, // ADC Absolute target
0x00,
0x00,
0x40, // ADC AbsoluteY target
0x00,
0x00,
0x00,
0x11, // ADC AbsoluteX target
0x00,
0x00,
0x00,
0x00,
0x00,
0x00,
0x00,
0x12, // ADC IndexedIndirectX target
0x00,
0x00,
0x00,
0x00,
0x00,
0x00,
0x00,
0x06, // ADC IndirectIndexedY target
];
let mut cpu = cpu::CPU::new();
// "Load" a program
cpu.memory.set_bytes(Address(0x0000), &zero_page_data);
cpu.memory.set_bytes(Address(0x4000), &program);
cpu.memory.set_bytes(Address(0x8000), &data);
cpu.registers.program_counter = Address(0x4000);
cpu.memory.set_bytes(Address(0x00), &zero_page_data);
cpu.memory.set_bytes(Address(0x10), &program);
cpu.registers.program_counter = Address(0x10);
cpu.run();
assert_eq!(7, cpu.registers.accumulator);
}
```