diff --git a/src/cpu/ctfe_d6502.d b/src/cpu/ctfe_d6502.d
index ced851d..34a1f41 100644
--- a/src/cpu/ctfe_d6502.d
+++ b/src/cpu/ctfe_d6502.d
@@ -422,7 +422,7 @@ string OpBody(int op, string chip, bool s, bool c)
             if (op != 0xAB)
                 ret ~= Load(_A ~ " = " ~ _X, env);
             else
-                return "";
+                ret ~= LAX_IMM_Undoc(env);
             break;
         case "SAX":
             ret ~= Store(_A ~ " & " ~ _X, env);
@@ -440,15 +440,20 @@ string OpBody(int op, string chip, bool s, bool c)
             ret ~= AXS_Undoc(env);
             break;
         case "AHX":
-            return "";
+            ret ~= Strange_Undoc(_A ~ " &" ~ _X, env);
+            break;
         case "SHY":
-            return "";
+            ret ~= Strange_Undoc(_Y, env);
+            break;
         case "SHX":
-            return "";
+            ret ~= Strange_Undoc(_X, env);
+            break;
         case "TAS":
-            return "";
+            ret ~= Strange_Undoc(_S ~ " = " ~ _A ~ " & " ~ _X, env);
+            break;
         case "XAA":
-            return "";
+            ret ~= XAA_Undoc(env);
+            break;
         case "SLO":
             ret ~= RMW_Undoc(ShiftLeft("data"),
                              SetNZ(_A ~ " |= data"), env);
@@ -870,6 +875,50 @@ string AXS_Undoc(Env env)
 }
 
 
+/*
+ * This opcode is unstable on certain machines; see
+ * http://visual6502.org/wiki/index.php?title=6502_Opcode_8B_(XAA,ANE)
+ */
+string XAA_Undoc(Env env)
+{
+    /*
+     * As far as I can tell, the only programs in the wild that depend
+     * on this opcode are certain C64 Mastertronic tape loaders; this
+     * magic value is used in the VICE emulator to make them work.
+     */
+    string MAGIC = "0xff";
+
+    return ReadInto(Local("ubyte", "data"), "address", env) ~
+           _A ~ " = ((" ~ _A ~ " | " ~ MAGIC ~ ") & " ~ _X ~ " & data);\n" ~
+           SetNZ(_A);
+}
+
+
+/*
+ * This opcode is unstable on certain machines.
+ */
+string LAX_IMM_Undoc(Env env)
+{
+    // From the VICE emulator.
+    string MAGIC = "0xee";
+
+    return ReadInto(Local("ubyte", "data"), "address", env) ~
+           _A ~ " = ((" ~ _A ~ " | " ~ MAGIC ~ ") & " ~ _X ~ " & data);\n" ~
+           SetNZ(_A);
+}
+
+
+// TODO: these are affected by DMA on the C64.
+string Strange_Undoc(string val, Env env)
+{
+    return "ubyte addrHi = cast(ubyte)((address >> 8) + 1);\n" ~
+           Local("ubyte", "data") ~ " = " ~ val ~ " & addrHi;\n" ~
+           "address = (guess == address) ? address : " ~
+           "((data << 8) | (address & 0xff));\n" ~
+           Write("address", "data", env);
+}
+
+
 string Local(string type)
 {
     version(OpFunctions)
diff --git a/test/test_new_cpu.d b/test/test_new_cpu.d
index 7bfc9fa..876518e 100644
--- a/test/test_new_cpu.d
+++ b/test/test_new_cpu.d
@@ -39,27 +39,8 @@ void main()
             test_opcode_timing!TX2(op, report2);
     }
 
-    test_func([0x00, 0x08, 0x10, 0x18, 0x28, 0x30, 0x38, 0x50, 0x58, 0x68,
-               0x70, 0x78, 0x90, 0xad, 0xb0, 0xb8, 0xd0, 0xd8, 0xf0, 0xf8,
-               0xae, 0xac, 0x8d, 0x8e, 0x8c, 0xe8, 0xc8, 0xca, 0x88, 0xcd,
-               0xec, 0xcc, 0x0d, 0x2d, 0x4d, 0xee, 0xce, 0x60, 0x6d, 0xed,
-               0x4c, 0x09, 0x29, 0x49, 0x69, 0xe9, 0xc9, 0xe0, 0xc0, 0xa9,
-               0xa2, 0xa0, 0x1d, 0x19, 0x3d, 0x39, 0x5d, 0x59, 0x7d, 0x79,
-               0xfd, 0xf9, 0xdd, 0xd9, 0xde, 0xfe, 0xbd, 0xb9, 0x9d, 0x99,
-               0xbe, 0xbc, 0x6c, 0x7c, 0xb2, 0x72, 0x32, 0xd2, 0x52, 0x12,
-               0xf2, 0x92, 0xaa, 0x8a, 0xa8, 0x98, 0xba, 0x9a, 0x0a, 0x0e,
-               0x1e, 0x48, 0x2c, 0x05, 0x25, 0x45, 0x65, 0xe5, 0xc5, 0xe4,
-               0xc4, 0xc6, 0xe6, 0x06, 0x26, 0x46, 0x66, 0xa5, 0x85, 0xa6,
-               0x86, 0xa4, 0x84, 0x24, 0x15, 0x35, 0x55, 0x75, 0xf5, 0xd5,
-               0xd6, 0xf6, 0x16, 0x36, 0x56, 0x76, 0xb5, 0x95, 0xb6, 0x96,
-               0xb4, 0x94, 0x01, 0x21, 0x41, 0x61, 0xe1, 0xc1, 0xa1, 0x81,
-               0x11, 0x31, 0x51, 0x71, 0xf1, 0xd1, 0xb1, 0x91, 0xda, 0x5a,
-               0x7a, 0xfa, 0x89, 0x34, 0x3c, 0x1a, 0x3a, 0x80, 0x64, 0x74,
-               0x14, 0x1c, 0x04, 0x0c, 0x40, 0x03, 0x07, 0x0f, 0x13, 0x17,
-               0x1b, 0x1f, 0x23, 0x27, 0x2f, 0x33, 0x37, 0x3b, 0x3f, 0x43,
-               0x47, 0x4f, 0x53, 0x57, 0x5b, 0x5f, 0x5c, 0x63, 0x67, 0x6f,
-               0x73, 0x77, 0x7b, 0x7f, 0xc3, 0xc7, 0xcf, 0xd3, 0xd7, 0xdb,
-               0xdf, 0xe3, 0xe7, 0xe7, 0xf3, 0xf7, 0xfb, 0xff, 0xbb, 0x83,
-               0x87, 0x8f, 0x97, 0xa3, 0xa7, 0xaf, 0xb3, 0xb7, 0xbf, 0x6b,
-               0x0b, 0x2b, 0x4b, 0xeb, 0xcb]);
+    ubyte[256] ops;
+    foreach (x; 0..256) ops[x] = cast(ubyte)x;
+
+    test_func(ops);
 }