From 93ae3ec6a0a89fd07bad638da89af7dfc837dc9c Mon Sep 17 00:00:00 2001
From: Preston Skupinski <skupinsk@cse.msu.edu>
Date: Sun, 1 May 2011 13:46:28 -0400
Subject: [PATCH] check if transferred value is zero and set the z bit of the p
 status register

---
 cpu.js | 28 ++++++++++++++++++++++++++--
 1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/cpu.js b/cpu.js
index d1fca1e..84589b9 100644
--- a/cpu.js
+++ b/cpu.js
@@ -115,7 +115,11 @@ var TYA = {
       // 8-bit index register to 16-bit accumulator. 
       // 16-bit index register to 16-bit accumulator.
       cpu.r.a = cpu.r.y; 
-    }  
+    } 
+    if(cpu.r.a===0) {
+      cpu.p.z = 1;
+    }
+    // TODO: Set n bit of the p status register.
   }
 };
 
@@ -142,6 +146,10 @@ var TAY = {
         cpu.r.y = cpu.r.a;
       }
     }
+    if(cpu.r.y===0) {
+      cpu.p.z = 1;
+    }
+    // TODO: Set n bit of the p status register.
   }
 };
 
@@ -163,7 +171,11 @@ var TXA = {
       // 8-bit index register to 16-bit accumulator. 
       // 16-bit index register to 16-bit accumulator.
       cpu.r.a = cpu.r.x; 
-    }  
+    }
+    if(cpu.r.a===0) {
+      cpu.p.z = 1;
+    }
+    // TODO: Set n bit of the p status register.
   }
 };
 
@@ -190,6 +202,10 @@ var TAX = {
         cpu.r.x = cpu.r.a;
       }
     }
+    if(cpu.r.x===0) {
+      cpu.p.z = 1;
+    }
+    // TODO: Set n bit of the p status register.
   }
 };
 
@@ -199,6 +215,10 @@ var TXY = {
   },
   execute:function(cpu) {
     cpu.r.y = cpu.r.x;
+    if(cpu.r.y===0) {
+      cpu.p.z = 1;
+    }
+    // TODO: Set n bit of the p status register.
   }
 };
 
@@ -208,6 +228,10 @@ var TYX = {
   },
   execute:function(cpu) {
     cpu.r.y = cpu.r.x;
+    if(cpu.r.y===0) {
+      cpu.p.z = 1;
+    }
+    // TODO: Set n bit of the p status register.
   }
 };