From b04190ce29a4dee75b3f8b6f9069d98950c87a52 Mon Sep 17 00:00:00 2001
From: Andrew Keeton <andrewrkeeton@gmail.com>
Date: Fri, 26 Sep 2014 03:52:13 -0400
Subject: [PATCH] Add some stuff.

---
 6502emu/src/main.rs | 70 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)

diff --git a/6502emu/src/main.rs b/6502emu/src/main.rs
index 32a3485..0b777a1 100644
--- a/6502emu/src/main.rs
+++ b/6502emu/src/main.rs
@@ -1,3 +1,73 @@
+struct Processor {
+	accumulator:     u8,
+	index_x:         u8,
+	index_y:         u8,
+	stack_pointer:   u8,
+	program_counter: u16,
+	status:          u8,
+}
+
+impl Processor {
+}
+
+#[deriving(PartialEq)]
+#[deriving(Eq)]
+#[deriving(PartialOrd)]
+#[deriving(Ord)]
+struct Address(u16);
+
+impl Address {
+	fn to_int(&self) -> u16 {
+		match *self {
+			Address(address_) => address_
+		}
+	}
+
+	fn min() -> Address { Address(0x0100) }
+	fn max() -> Address { Address(0x01ff) }
+
+	fn is_valid(&self) -> bool {
+		Address::min() <= *self && *self <= Address::max()
+	}
+}
+
+struct Memory {
+	bytes: [u8,.. 256]
+}
+
+impl Memory {
+	fn address_to_byte_offset(address: &Address) -> uint {
+		(address.to_int() - Address::min().to_int()) as uint
+	}
+
+	fn get_byte(&self, address: &Address) -> u8 {
+		if !address.is_valid()
+		{
+			fail!("Invalid address.");
+		}
+		else
+		{
+			return self.bytes[Memory::address_to_byte_offset(address)];
+		}
+	}
+
+	// Sets the byte at the given address to the given value and returns the
+	// previous value at the address. 
+	fn set_byte(&mut self, address: &Address, value: u8) -> u8 {
+		if !address.is_valid()
+		{
+			fail!("Invalid address.");
+		}
+		else
+		{
+			let old_value = self.get_byte(address);
+			self.bytes[Memory::address_to_byte_offset(address)] = value;
+
+			return old_value;
+		}
+	}
+}
+
 fn main() {
 	println!("Hello, world!")
 }