From eb5c3f3c2aedba14ee45363e4c26c0f2fb189a56 Mon Sep 17 00:00:00 2001
From: Andrew Keeton <andrewrkeeton@gmail.com>
Date: Thu, 6 Nov 2014 19:38:56 -0500
Subject: [PATCH 1/3] Add branch_if_carry_set_test().

---
 src/machine.rs | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/machine.rs b/src/machine.rs
index 357b01b..5fbc7c1 100644
--- a/src/machine.rs
+++ b/src/machine.rs
@@ -886,6 +886,19 @@ fn branch_if_carry_clear_test() {
     assert_eq!(machine.registers.program_counter, Address(0xABCD));
 }
 
+#[test]
+fn branch_if_carry_set_test() {
+    let mut machine = Machine::new();
+
+    machine.execute_instruction((instruction::CLC, instruction::UseImplied));
+    machine.branch_if_carry_set(Address(0xABCD));
+    assert_eq!(machine.registers.program_counter, Address(0));
+
+    machine.execute_instruction((instruction::SEC, instruction::UseImplied));
+    machine.branch_if_carry_set(Address(0xABCD));
+    assert_eq!(machine.registers.program_counter, Address(0xABCD));
+}
+
 #[test]
 fn branch_if_minus_test() {
     {

From da6a28f63912b63c22780c6ec20bbefee1ba8dfa Mon Sep 17 00:00:00 2001
From: Andrew Keeton <andrewrkeeton@gmail.com>
Date: Thu, 6 Nov 2014 19:39:46 -0500
Subject: [PATCH 2/3] Add branch_if_carry_set().

---
 src/machine.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/machine.rs b/src/machine.rs
index 5fbc7c1..039fa6f 100644
--- a/src/machine.rs
+++ b/src/machine.rs
@@ -554,6 +554,12 @@ impl Machine {
         }
     }
 
+    fn branch_if_carry_set(&mut self, addr: Address) {
+        if self.registers.status.contains(PS_CARRY) {
+            self.registers.program_counter = addr;
+        }
+    }
+
     fn branch_if_minus(&mut self, addr: Address) {
         if self.registers.status.contains(PS_NEGATIVE) {
             self.registers.program_counter = addr;

From 59168cbbe449dec96b369f075569c69f7912f533 Mon Sep 17 00:00:00 2001
From: Andrew Keeton <andrewrkeeton@gmail.com>
Date: Thu, 6 Nov 2014 19:42:08 -0500
Subject: [PATCH 3/3] Add BCS to execute_instruction().

---
 src/machine.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/machine.rs b/src/machine.rs
index 039fa6f..1b90a47 100644
--- a/src/machine.rs
+++ b/src/machine.rs
@@ -116,6 +116,11 @@ impl Machine {
                 self.branch_if_carry_clear(addr);
             }
 
+            (instruction::BCS, instruction::UseRelative(rel)) => {
+                let addr = self.registers.program_counter
+                         + AddressDiff(rel as i32);
+                self.branch_if_carry_set(addr);
+            }
 
             (instruction::BIT, instruction::UseAddress(addr)) => {
                 let a: u8 = self.registers.accumulator as u8;