From 2b3874879e64588ed68743ca4e101fab1c99b8bd Mon Sep 17 00:00:00 2001
From: Brad Grantham <grantham@plunk.org>
Date: Sun, 6 Nov 2016 13:30:23 -0800
Subject: [PATCH] CMP abs,Y

---
 apple2e.cpp | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/apple2e.cpp b/apple2e.cpp
index 675531c..564cdc2 100644
--- a/apple2e.cpp
+++ b/apple2e.cpp
@@ -502,6 +502,17 @@ struct CPU6502
                 break;
             }
 
+            case 0xD9: {
+                int addr = read_pc_inc(bus) + read_pc_inc(bus) * 256;
+                if(debug & DEBUG_DECODE) printf("CMP %04X, Y\n", addr);
+                unsigned char m = bus.read(addr + y);
+                flag_change(C, m <= a);
+                m = a - m;
+                flag_change(N, m & 0x80);
+                flag_change(Z, m == 0);
+                break;
+            }
+
             case 0xB9: {
                 int addr = read_pc_inc(bus) + read_pc_inc(bus) * 256;
                 if(debug & DEBUG_DECODE) printf("LDA %04X, Y\n", addr);