Merge pull request #19 from GooseDB/examples

New example: Euclidean algorithm

Cargo.toml

@@ -33,6 +33,7 @@ license = "BSD-3-Clause"
 version = "0.1.0"
 authors = ["The 6502-rs Developers"]
 build = "build.rs"
+exclude = ["examples/**"]
 
 [lib]
 # This will look in src/lib.rs

examples/euclidean_algo.rs

@@ -0,0 +1,47 @@
+extern crate mos6502;
+use mos6502::address::Address;
+use mos6502::cpu;
+
+fn main() {
+    println!("Enter two numbers (< 128) to know their GCD:");
+    let mut input = String::new();
+    std::io::stdin().read_line(&mut input).unwrap();
+
+    let zero_page_data = input
+        .trim()
+        .split(' ')
+        .map(|s| s.parse::<u8>().unwrap())
+        .collect::<Vec<u8>>();
+
+    let program = [
+    // (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 mut cpu = cpu::CPU::new();
+
+    cpu.memory.set_bytes(Address(0x00), &zero_page_data);
+    cpu.memory.set_bytes(Address(0x10), &program);
+    cpu.registers.program_counter = Address(0x10);
+
+    cpu.run();
+
+    println!("GCD is {:?}", cpu.registers.accumulator);
+}