From 7530f815076316d52307377f2b9292c615fcc7fc Mon Sep 17 00:00:00 2001
From: Mike Naberezny <mike@naberezny.com>
Date: Wed, 12 Mar 2014 10:02:25 -0700
Subject: [PATCH] Fix 65C02 opcode $D2: CMP Zero Page, Indirect

---
 CHANGES.txt                         |  2 ++
 py65/devices/mpu65c02.py            |  2 +-
 py65/tests/devices/test_mpu65c02.py | 38 ++++++++++++++++++++++++++---
 3 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/CHANGES.txt b/CHANGES.txt
index d19fd5b..27ee689 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,5 +1,7 @@
 0.19-dev (Next Release)
 
+  - Fixed 65C02 opcode $D2: CMP Zero Page, Indirect.
+
   - Blocking character input at $F005 has been removed.  The I/O area
     was designed to be compatible with Michal Kowalski's simulator,
     and it uses this address for another purpose.  Examples that depended
diff --git a/py65/devices/mpu65c02.py b/py65/devices/mpu65c02.py
index 9b63890..a2c3b36 100644
--- a/py65/devices/mpu65c02.py
+++ b/py65/devices/mpu65c02.py
@@ -274,7 +274,7 @@ class MPU(mpu6502.MPU):
 
     @instruction(name="CMP", mode='zpi', cycles=5)
     def inst_0xd2(self):
-        self.opCPY(self.ZeroPageIndirectAddr)
+        self.opCMPR(self.ZeroPageIndirectAddr, self.a)
         self.pc += 1
 
     @instruction(name="SMB5", mode="zpg", cycles=5)
diff --git a/py65/tests/devices/test_mpu65c02.py b/py65/tests/devices/test_mpu65c02.py
index dd258ce..e2b84fd 100644
--- a/py65/tests/devices/test_mpu65c02.py
+++ b/py65/tests/devices/test_mpu65c02.py
@@ -13,7 +13,7 @@ class MPUTests(unittest.TestCase, Common6502Tests):
 
     # ADC Indirect, Indexed (X)
 
-    def test_adc_ind_indexed_has_page_wrap_bug(self):
+    def test_adc_ind_indexed_does_not_have_wrap_bug(self):
         mpu = self._make_mpu()
         mpu.a = 0x01
         mpu.x = 0xFF
@@ -476,9 +476,41 @@ class MPUTests(unittest.TestCase, Common6502Tests):
         self.assertEqual(mpu.BREAK, mpu.p & mpu.BREAK)
         self.assertEqual(0, mpu.p & mpu.DECIMAL)
 
+    # CMP Zero Page, Indirect
+
+    def test_cmp_zpi_sets_z_flag_if_equal(self):
+        mpu = self._make_mpu()
+        mpu.a = 0x42
+        # $0000 AND ($10)
+        # $0010 Vector to $ABCD
+        self._write(mpu.memory, 0x0000, (0xd2, 0x10))
+        self._write(mpu.memory, 0x0010, (0xCD, 0xAB))
+        mpu.memory[0xABCD] = 0x42
+        mpu.step()
+        self.assertEqual(0x0002, mpu.pc)
+        self.assertEqual(5, mpu.processorCycles)
+        self.assertEqual(0x42, mpu.a)
+        self.assertEqual(mpu.ZERO, mpu.p & mpu.ZERO)
+        self.assertEqual(0, mpu.p & mpu.NEGATIVE)
+
+    def test_cmp_zpi_resets_z_flag_if_unequal(self):
+        mpu = self._make_mpu()
+        mpu.a = 0x43
+        # $0000 AND ($10)
+        # $0010 Vector to $ABCD
+        self._write(mpu.memory, 0x0000, (0xd2, 0x10))
+        self._write(mpu.memory, 0x0010, (0xCD, 0xAB))
+        mpu.memory[0xABCD] = 0x42
+        mpu.step()
+        self.assertEqual(0x0002, mpu.pc)
+        self.assertEqual(5, mpu.processorCycles)
+        self.assertEqual(0x43, mpu.a)
+        self.assertEqual(0, mpu.p & mpu.ZERO)
+        self.assertEqual(0, mpu.p & mpu.NEGATIVE)
+
     # CMP Indirect, Indexed (X)
 
-    def test_cmp_ind_x_has_page_wrap_bug(self):
+    def test_cmp_ind_x_does_not_have_page_wrap_bug(self):
         mpu = self._make_mpu()
         mpu.p = 0
         mpu.a = 0x42
@@ -944,7 +976,7 @@ class MPUTests(unittest.TestCase, Common6502Tests):
 
     # SBC Indirect, Indexed (X)
 
-    def test_sbc_ind_x_has_page_wrap_bug(self):
+    def test_sbc_ind_x_does_not_have_page_wrap_bug(self):
         mpu = self._make_mpu()
         mpu.p = mpu.CARRY
         mpu.a = 0x03