diff --git a/stella/src/debugger/Debugger.cxx b/stella/src/debugger/Debugger.cxx
index 6eb6cb339..1938f8dd5 100644
--- a/stella/src/debugger/Debugger.cxx
+++ b/stella/src/debugger/Debugger.cxx
@@ -13,7 +13,7 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: Debugger.cxx,v 1.67 2005-07-16 21:29:44 stephena Exp $
+// $Id: Debugger.cxx,v 1.68 2005-07-18 02:03:40 urchlay Exp $
 //============================================================================
 
 #include "bspf.hxx"
@@ -98,6 +98,7 @@ void Debugger::initialize()
   string initBreak = myOSystem->settings().getString("break");
   if(initBreak != "") run("break " + initBreak);
   myOSystem->settings().setString("break", "", false);
+  autoExec();
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -129,10 +130,6 @@ void Debugger::setConsole(Console* console)
   delete myTiaDebug;
   myTiaDebug = new TIADebug(this, myConsole);
 
-  // Let the parser know about the new subsystems (so YaccParser can use them)
-// FIXME
-//  myParser->updateDebugger(this, myConsole);
-
   autoLoadSymbols(myOSystem->romFile());
 
   saveOldState();
@@ -164,6 +161,20 @@ void Debugger::autoLoadSymbols(string fileName) {
 	//	cerr << "loading syms from file " << file << ": " << ret << endl;
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+void Debugger::autoExec() {
+	string file = myOSystem->romFile();
+
+	string::size_type pos;
+	if( (pos = file.find_last_of('.')) != string::npos ) {
+		file.replace(pos, file.size(), ".stella");
+	} else {
+		file += ".stella";
+	}
+	myPrompt->print("\nautoExec():\n" + myParser->exec(file));
+	myPrompt->printPrompt();
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 const string Debugger::run(const string& command)
 {
diff --git a/stella/src/debugger/Debugger.hxx b/stella/src/debugger/Debugger.hxx
index d30d5b4de..127b0f9e6 100644
--- a/stella/src/debugger/Debugger.hxx
+++ b/stella/src/debugger/Debugger.hxx
@@ -13,7 +13,7 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: Debugger.hxx,v 1.54 2005-07-15 15:27:29 stephena Exp $
+// $Id: Debugger.hxx,v 1.55 2005-07-18 02:03:40 urchlay Exp $
 //============================================================================
 
 #ifndef DEBUGGER_HXX
@@ -63,7 +63,7 @@ typedef uInt16 (Debugger::*DEBUGGER_WORD_METHOD)();
   for all debugging operations in Stella (parser, 6502 debugger, etc).
 
   @author  Stephen Anthony
-  @version $Id: Debugger.hxx,v 1.54 2005-07-15 15:27:29 stephena Exp $
+  @version $Id: Debugger.hxx,v 1.55 2005-07-18 02:03:40 urchlay Exp $
 */
 class Debugger : public DialogContainer
 {
@@ -285,6 +285,7 @@ class Debugger : public DialogContainer
 
     void reset();
     void autoLoadSymbols(string file);
+    void autoExec();
     void clearAllBreakPoints();
 
     void formatFlags(BoolArray& b, char *out);
diff --git a/stella/src/debugger/DebuggerParser.cxx b/stella/src/debugger/DebuggerParser.cxx
index 1a8cd2440..2c882b560 100644
--- a/stella/src/debugger/DebuggerParser.cxx
+++ b/stella/src/debugger/DebuggerParser.cxx
@@ -13,15 +13,18 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: DebuggerParser.cxx,v 1.63 2005-07-17 15:50:34 urchlay Exp $
+// $Id: DebuggerParser.cxx,v 1.64 2005-07-18 02:03:40 urchlay Exp $
 //============================================================================
 
 #include "bspf.hxx"
+#include <iostream>
+#include <fstream>
 #include "Debugger.hxx"
 #include "CpuDebug.hxx"
 #include "DebuggerParser.hxx"
 #include "YaccParser.hxx"
 #include "M6502.hxx"
+#include "Expression.hxx"
 
 #include "DebuggerParser.hxx"
 
@@ -154,6 +157,14 @@ Command DebuggerParser::commands[] = {
 		&DebuggerParser::executeDump
 	},
 
+	{
+		"exec",
+		"Execute script file",
+		true,
+		{ kARG_FILE, kARG_END_ARGS },
+		&DebuggerParser::executeExec
+	},
+
 	{
 		"frame",
 		"Advance emulation by xx frames (default=1)",
@@ -929,7 +940,7 @@ bool DebuggerParser::validateArgs(int cmd) {
 
 			case kARG_MULTI_BYTE:
 			case kARG_MULTI_WORD:
-				break; // FIXME: implement!
+				break; // FIXME: validate these (for now, any number's allowed)
 
 			default:
 				commandResult = red("too many arguments");
@@ -951,8 +962,10 @@ bool DebuggerParser::validateArgs(int cmd) {
 
 // main entry point: PromptWidget calls this method.
 string DebuggerParser::run(const string& command) {
+
+	/*
+		// this was our parser test code. Left for reference.
 	static Expression *lastExpression;
-	int i=0;
 
 	// special case: parser testing
 	if(strncmp(command.c_str(), "expr ", 5) == 0) {
@@ -983,10 +996,16 @@ string DebuggerParser::run(const string& command) {
 			commandResult = "no valid expr";
 		return commandResult;
 	}
+	*/
 
 	getArgs(command);
+#ifdef EXPR_REF_COUNT
+	extern int refCount;
+	cerr << "Expression count: " << refCount << endl;
+#endif
 	commandResult = "";
 
+	int i=0;
 	do {
 		if( subStringMatch(verb, commands[i].cmdString.c_str()) ) {
 			if( validateArgs(i) )
@@ -1041,6 +1060,42 @@ const char *DebuggerParser::getCompletionPrefix() {
 	return compPrefix.c_str();
 }
 
+string DebuggerParser::exec(const string& cmd, bool verbose) {
+	string file = cmd;
+	string ret;
+	int count = 0;
+	char buffer[256]; // FIXME: static buffers suck
+
+	string::size_type pos;
+	if( (pos = file.find_last_of('.')) == string::npos ) {
+		file += ".stella";
+	}
+
+	ifstream in(file.c_str());
+	if(!in.is_open())
+		return red("file \"" + file + "\" not found.");
+
+	while( !in.eof() ) {
+		if(!in.getline(buffer, 255))
+			break;
+
+		count++;
+		if(verbose) {
+			ret += "exec> ";
+			ret += buffer;
+			ret += "\n";
+			ret += run(buffer);
+			ret += "\n";
+		}
+	}
+	ret += "Executed ";
+	ret += debugger->valueToString(count);
+	ret += " commands from \"";
+	ret += file;
+	ret += "\"\n";
+	return ret;
+}
+
 ////// executor methods for commands[] array. All are void, no args.
 
 // "a"
@@ -1203,6 +1258,11 @@ void DebuggerParser::executeDump() {
 	commandResult = dump();
 }
 
+// "exec"
+void DebuggerParser::executeExec() {
+	commandResult = exec(argStrings[0]);
+}
+
 // "height"
 void DebuggerParser::executeHeight() {
 	int height = debugger->setHeight(args[0]);
diff --git a/stella/src/debugger/DebuggerParser.hxx b/stella/src/debugger/DebuggerParser.hxx
index 842e81978..ef206d5b4 100644
--- a/stella/src/debugger/DebuggerParser.hxx
+++ b/stella/src/debugger/DebuggerParser.hxx
@@ -13,7 +13,7 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: DebuggerParser.hxx,v 1.34 2005-07-17 15:50:36 urchlay Exp $
+// $Id: DebuggerParser.hxx,v 1.35 2005-07-18 02:03:40 urchlay Exp $
 //============================================================================
 
 #ifndef DEBUGGER_PARSER_HXX
@@ -50,6 +50,7 @@ class DebuggerParser
 		int countCompletions(const char *in);
 		const char *getCompletions();
 		const char *getCompletionPrefix();
+		string exec(const string& cmd, bool verbose=true);
 
 		static inline string red(string msg ="") {
 			// This is TIA color 0x34. The octal value is 0x80+(0x34>>1).
@@ -107,6 +108,7 @@ class DebuggerParser
 		void executeDelwatch();
 		void executeDisasm();
 		void executeDump();
+		void executeExec();
 		void executeFrame();
 		void executeHeight();
 		void executeHelp();
diff --git a/stella/src/debugger/Expression.cxx b/stella/src/debugger/Expression.cxx
index 0dd136f3f..5fa0bc63f 100644
--- a/stella/src/debugger/Expression.cxx
+++ b/stella/src/debugger/Expression.cxx
@@ -13,21 +13,34 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: Expression.cxx,v 1.1 2005-07-12 17:02:35 stephena Exp $
+// $Id: Expression.cxx,v 1.2 2005-07-18 02:03:41 urchlay Exp $
 //============================================================================
 
 #include "Expression.hxx"
 
+#ifdef EXPR_REF_COUNT
+#include "bspf.hxx"
+    int refCount = 0;
+#endif
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 Expression::Expression(Expression* lhs, Expression* rhs)
   : myLHS(lhs),
     myRHS(rhs)
 {
+#ifdef EXPR_REF_COUNT
+  refCount++;
+  cerr << "new Expression::Expression()" << endl;
+#endif
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 Expression::~Expression()
 {
+#ifdef EXPR_REF_COUNT
+  refCount--;
+  cerr << "~Expression::Expression()" << endl;
+#endif
   delete myLHS;
   delete myRHS;
 }
diff --git a/stella/src/debugger/Expression.hxx b/stella/src/debugger/Expression.hxx
index 1c0cd5a1a..2263c2d38 100644
--- a/stella/src/debugger/Expression.hxx
+++ b/stella/src/debugger/Expression.hxx
@@ -13,12 +13,16 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: Expression.hxx,v 1.1 2005-07-12 17:02:35 stephena Exp $
+// $Id: Expression.hxx,v 1.2 2005-07-18 02:03:41 urchlay Exp $
 //============================================================================
 
 #ifndef EXPRESSION_HXX
 #define EXPRESSION_HXX
 
+// define this to count Expression instances. Only useful for debugging
+// Stella itself.
+//#define EXPR_REF_COUNT
+
 /**
   This class provides an implementation of an expression node, which
   is a construct that is given two other expressions and evaluates and
@@ -26,7 +30,7 @@
   can represent complex expression statements.
 
   @author  Stephen Anthony
-  @version $Id: Expression.hxx,v 1.1 2005-07-12 17:02:35 stephena Exp $
+  @version $Id: Expression.hxx,v 1.2 2005-07-18 02:03:41 urchlay Exp $
 */
 class Expression
 {
diff --git a/stella/src/emucore/m6502/src/M6502.cxx b/stella/src/emucore/m6502/src/M6502.cxx
index c8d117d82..60e3d218f 100644
--- a/stella/src/emucore/m6502/src/M6502.cxx
+++ b/stella/src/emucore/m6502/src/M6502.cxx
@@ -13,7 +13,7 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: M6502.cxx,v 1.10 2005-07-17 15:50:37 urchlay Exp $
+// $Id: M6502.cxx,v 1.11 2005-07-18 02:03:41 urchlay Exp $
 //============================================================================
 
 #include "M6502.hxx"
@@ -113,6 +113,7 @@ void M6502::addCondBreak(Expression *e, string name)
 void M6502::delCondBreak(unsigned int brk)
 {
   if(brk < myBreakConds.size()) {
+    delete myBreakConds[brk];
     myBreakConds.remove_at(brk);
     myBreakCondNames.remove_at(brk);
   }
@@ -121,6 +122,8 @@ void M6502::delCondBreak(unsigned int brk)
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void M6502::clearCondBreaks()
 {
+  for(unsigned int i=0; i<myBreakConds.size(); i++)
+    delete myBreakConds[i];
   myBreakConds.clear();
   myBreakCondNames.clear();
 }
diff --git a/stella/src/yacc/YaccParser.cxx b/stella/src/yacc/YaccParser.cxx
index 65d34f11e..52814419a 100644
--- a/stella/src/yacc/YaccParser.cxx
+++ b/stella/src/yacc/YaccParser.cxx
@@ -13,7 +13,7 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: YaccParser.cxx,v 1.12 2005-07-16 23:46:36 urchlay Exp $
+// $Id: YaccParser.cxx,v 1.13 2005-07-18 02:03:41 urchlay Exp $
 //
 //   Based on code from ScummVM - Scumm Interpreter
 //   Copyright (C) 2002-2004 The ScummVM project
@@ -25,6 +25,8 @@
 //extern "C" {
 //#endif
 
+#include <vector>
+
 #include "Expression.hxx"
 #include "CpuDebug.hxx"
 
diff --git a/stella/src/yacc/stella.y b/stella/src/yacc/stella.y
index cb9043cb9..4657e25c1 100644
--- a/stella/src/yacc/stella.y
+++ b/stella/src/yacc/stella.y
@@ -1,6 +1,8 @@
 %{
 #include <stdio.h>
 
+Expression* lastExp = 0;
+
 #define YYERROR_VERBOSE 1
 
 int yylex();
@@ -10,6 +12,8 @@ void yyerror(char *e) {
 	//fprintf(stderr, "%s at token \"%s\"\n", e, yytext);
 	fprintf(stderr, "%s\n", e);
 	errMsg = e;
+	if(lastExp)
+		delete lastExp;
 }
 
 %}
@@ -48,35 +52,35 @@ void yyerror(char *e) {
 statement:	expression { fprintf(stderr, "\ndone\n"); result.exp = $1; }
 	;
 
-expression:	expression '+' expression { fprintf(stderr, " +"); $$ = new PlusExpression($1, $3); }
-	|	expression '-' expression { fprintf(stderr, " -"); $$ = new MinusExpression($1, $3); }
-	|	expression '*' expression { fprintf(stderr, " *"); $$ = new MultExpression($1, $3); }
-	|	expression '/' expression { fprintf(stderr, " /"); $$ = new DivExpression($1, $3); }
-	|	expression '%' expression { fprintf(stderr, " %%"); $$ = new ModExpression($1, $3);  }
-	|	expression '&' expression { fprintf(stderr, " &"); $$ = new BinAndExpression($1, $3); }
-	|	expression '|' expression { fprintf(stderr, " |"); $$ = new BinOrExpression($1, $3); }
-	|	expression '^' expression { fprintf(stderr, " ^"); $$ = new BinXorExpression($1, $3); }
-	|	expression '<' expression { fprintf(stderr, " <"); $$ = new LessExpression($1, $3); }
-	|	expression '>' expression { fprintf(stderr, " >"); $$ = new GreaterExpression($1, $3); }
-	|	expression GTE expression { fprintf(stderr, " >="); $$ = new GreaterEqualsExpression($1, $3); }
-	|	expression LTE expression { fprintf(stderr, " <="); $$ = new LessEqualsExpression($1, $3); }
-	|	expression NE  expression { fprintf(stderr, " !="); $$ = new NotEqualsExpression($1, $3); }
-	|	expression EQ  expression { fprintf(stderr, " =="); $$ = new EqualsExpression($1, $3); }
-	|	expression SHR expression { fprintf(stderr, " >>"); $$ = new ShiftRightExpression($1, $3); }
-	|	expression SHL expression { fprintf(stderr, " <<"); $$ = new ShiftLeftExpression($1, $3); }
-	|	expression LOG_OR expression { fprintf(stderr, " ||"); $$ = new LogOrExpression($1, $3); }
-	|	expression LOG_AND expression { fprintf(stderr, " &&"); $$ = new LogAndExpression($1, $3); }
-	|	'-' expression %prec UMINUS	{ fprintf(stderr, " U-"); $$ = new UnaryMinusExpression($2); }
-	|	'~' expression %prec UMINUS	{ fprintf(stderr, " ~"); $$ = new BinNotExpression($2); }
-	|	'!' expression %prec UMINUS	{ fprintf(stderr, " !"); $$ = new LogNotExpression($2); }
-	|	'*' expression %prec DEREF { fprintf(stderr, " U*"); $$ = new ByteDerefExpression($2); }
-	|	'@' expression %prec DEREF { fprintf(stderr, " U@"); $$ = new WordDerefExpression($2); }
-	|	'<' expression { fprintf(stderr, " U<");  $$ = new LoByteExpression($2);  }
-	|	'>' expression { fprintf(stderr, " U>");  $$ = new HiByteExpression($2);  }
-	|	'(' expression ')'	{ fprintf(stderr, " ()"); $$ = $2; }
-	|	NUMBER { fprintf(stderr, " %d", $1); $$ = new ConstExpression($1); }
-	|	EQUATE { fprintf(stderr, " %s", $1); $$ = new EquateExpression($1); }
-	|	INT_METHOD { fprintf(stderr, " (intMethod)"); $$ = new IntMethodExpression($1); }
+expression:	expression '+' expression { fprintf(stderr, " +"); $$ = new PlusExpression($1, $3); lastExp = $$; }
+	|	expression '-' expression { fprintf(stderr, " -"); $$ = new MinusExpression($1, $3); lastExp = $$; }
+	|	expression '*' expression { fprintf(stderr, " *"); $$ = new MultExpression($1, $3); lastExp = $$; }
+	|	expression '/' expression { fprintf(stderr, " /"); $$ = new DivExpression($1, $3); lastExp = $$; }
+	|	expression '%' expression { fprintf(stderr, " %%"); $$ = new ModExpression($1, $3);  lastExp = $$; }
+	|	expression '&' expression { fprintf(stderr, " &"); $$ = new BinAndExpression($1, $3); lastExp = $$; }
+	|	expression '|' expression { fprintf(stderr, " |"); $$ = new BinOrExpression($1, $3); lastExp = $$; }
+	|	expression '^' expression { fprintf(stderr, " ^"); $$ = new BinXorExpression($1, $3); lastExp = $$; }
+	|	expression '<' expression { fprintf(stderr, " <"); $$ = new LessExpression($1, $3); lastExp = $$; }
+	|	expression '>' expression { fprintf(stderr, " >"); $$ = new GreaterExpression($1, $3); lastExp = $$; }
+	|	expression GTE expression { fprintf(stderr, " >="); $$ = new GreaterEqualsExpression($1, $3); lastExp = $$; }
+	|	expression LTE expression { fprintf(stderr, " <="); $$ = new LessEqualsExpression($1, $3); lastExp = $$; }
+	|	expression NE  expression { fprintf(stderr, " !="); $$ = new NotEqualsExpression($1, $3); lastExp = $$; }
+	|	expression EQ  expression { fprintf(stderr, " =="); $$ = new EqualsExpression($1, $3); lastExp = $$; }
+	|	expression SHR expression { fprintf(stderr, " >>"); $$ = new ShiftRightExpression($1, $3); lastExp = $$; }
+	|	expression SHL expression { fprintf(stderr, " <<"); $$ = new ShiftLeftExpression($1, $3); lastExp = $$; }
+	|	expression LOG_OR expression { fprintf(stderr, " ||"); $$ = new LogOrExpression($1, $3); lastExp = $$; }
+	|	expression LOG_AND expression { fprintf(stderr, " &&"); $$ = new LogAndExpression($1, $3); lastExp = $$; }
+	|	'-' expression %prec UMINUS	{ fprintf(stderr, " U-"); $$ = new UnaryMinusExpression($2); lastExp = $$; }
+	|	'~' expression %prec UMINUS	{ fprintf(stderr, " ~"); $$ = new BinNotExpression($2); lastExp = $$; }
+	|	'!' expression %prec UMINUS	{ fprintf(stderr, " !"); $$ = new LogNotExpression($2); lastExp = $$; }
+	|	'*' expression %prec DEREF { fprintf(stderr, " U*"); $$ = new ByteDerefExpression($2); lastExp = $$; }
+	|	'@' expression %prec DEREF { fprintf(stderr, " U@"); $$ = new WordDerefExpression($2); lastExp = $$; }
+	|	'<' expression { fprintf(stderr, " U<");  $$ = new LoByteExpression($2);  lastExp = $$; }
+	|	'>' expression { fprintf(stderr, " U>");  $$ = new HiByteExpression($2);  lastExp = $$; }
+	|	'(' expression ')'	{ fprintf(stderr, " ()"); $$ = $2; lastExp = $$; }
+	|	NUMBER { fprintf(stderr, " %d", $1); $$ = new ConstExpression($1); lastExp = $$; }
+	|	EQUATE { fprintf(stderr, " %s", $1); $$ = new EquateExpression($1); lastExp = $$; }
+	|	INT_METHOD { fprintf(stderr, " (intMethod)"); $$ = new IntMethodExpression($1); lastExp = $$; }
 	|  ERR { fprintf(stderr, " ERR"); yyerror("Invalid label or constant"); return 1; }
 	;
 %%
diff --git a/stella/src/yacc/y.tab.c b/stella/src/yacc/y.tab.c
index 638b529e5..d9bcaf8ec 100644
--- a/stella/src/yacc/y.tab.c
+++ b/stella/src/yacc/y.tab.c
@@ -23,6 +23,8 @@
 
 #include <stdio.h>
 
+Expression* lastExp = 0;
+
 #define YYERROR_VERBOSE 1
 
 int yylex();
@@ -32,10 +34,12 @@ void yyerror(char *e) {
 	//fprintf(stderr, "%s at token \"%s\"\n", e, yytext);
 	fprintf(stderr, "%s\n", e);
 	errMsg = e;
+	if(lastExp)
+		delete lastExp;
 }
 
 
-#line 17 "stella.y"
+#line 21 "stella.y"
 #ifndef YYSTYPE
 typedef union {
 	int val;
@@ -121,10 +125,10 @@ static const short yyrhs[] =
 /* YYRLINE[YYN] -- source line where rule number YYN was defined. */
 static const short yyrline[] =
 {
-       0,    48,    51,    52,    53,    54,    55,    56,    57,    58,
-      59,    60,    61,    62,    63,    64,    65,    66,    67,    68,
-      69,    70,    71,    72,    73,    74,    75,    76,    77,    78,
-      79,    80
+       0,    52,    55,    56,    57,    58,    59,    60,    61,    62,
+      63,    64,    65,    66,    67,    68,    69,    70,    71,    72,
+      73,    74,    75,    76,    77,    78,    79,    80,    81,    82,
+      83,    84
 };
 #endif
 
@@ -948,128 +952,128 @@ yyreduce:
   switch (yyn) {
 
 case 1:
-#line 48 "stella.y"
+#line 52 "stella.y"
 { fprintf(stderr, "\ndone\n"); result.exp = yyvsp[0].exp; }
     break;
 case 2:
-#line 51 "stella.y"
-{ fprintf(stderr, " +"); yyval.exp = new PlusExpression(yyvsp[-2].exp, yyvsp[0].exp); }
+#line 55 "stella.y"
+{ fprintf(stderr, " +"); yyval.exp = new PlusExpression(yyvsp[-2].exp, yyvsp[0].exp); lastExp = yyval.exp; }
     break;
 case 3:
-#line 52 "stella.y"
-{ fprintf(stderr, " -"); yyval.exp = new MinusExpression(yyvsp[-2].exp, yyvsp[0].exp); }
+#line 56 "stella.y"
+{ fprintf(stderr, " -"); yyval.exp = new MinusExpression(yyvsp[-2].exp, yyvsp[0].exp); lastExp = yyval.exp; }
     break;
 case 4:
-#line 53 "stella.y"
-{ fprintf(stderr, " *"); yyval.exp = new MultExpression(yyvsp[-2].exp, yyvsp[0].exp); }
+#line 57 "stella.y"
+{ fprintf(stderr, " *"); yyval.exp = new MultExpression(yyvsp[-2].exp, yyvsp[0].exp); lastExp = yyval.exp; }
     break;
 case 5:
-#line 54 "stella.y"
-{ fprintf(stderr, " /"); yyval.exp = new DivExpression(yyvsp[-2].exp, yyvsp[0].exp); }
+#line 58 "stella.y"
+{ fprintf(stderr, " /"); yyval.exp = new DivExpression(yyvsp[-2].exp, yyvsp[0].exp); lastExp = yyval.exp; }
     break;
 case 6:
-#line 55 "stella.y"
-{ fprintf(stderr, " %%"); yyval.exp = new ModExpression(yyvsp[-2].exp, yyvsp[0].exp);  }
+#line 59 "stella.y"
+{ fprintf(stderr, " %%"); yyval.exp = new ModExpression(yyvsp[-2].exp, yyvsp[0].exp);  lastExp = yyval.exp; }
     break;
 case 7:
-#line 56 "stella.y"
-{ fprintf(stderr, " &"); yyval.exp = new BinAndExpression(yyvsp[-2].exp, yyvsp[0].exp); }
+#line 60 "stella.y"
+{ fprintf(stderr, " &"); yyval.exp = new BinAndExpression(yyvsp[-2].exp, yyvsp[0].exp); lastExp = yyval.exp; }
     break;
 case 8:
-#line 57 "stella.y"
-{ fprintf(stderr, " |"); yyval.exp = new BinOrExpression(yyvsp[-2].exp, yyvsp[0].exp); }
+#line 61 "stella.y"
+{ fprintf(stderr, " |"); yyval.exp = new BinOrExpression(yyvsp[-2].exp, yyvsp[0].exp); lastExp = yyval.exp; }
     break;
 case 9:
-#line 58 "stella.y"
-{ fprintf(stderr, " ^"); yyval.exp = new BinXorExpression(yyvsp[-2].exp, yyvsp[0].exp); }
+#line 62 "stella.y"
+{ fprintf(stderr, " ^"); yyval.exp = new BinXorExpression(yyvsp[-2].exp, yyvsp[0].exp); lastExp = yyval.exp; }
     break;
 case 10:
-#line 59 "stella.y"
-{ fprintf(stderr, " <"); yyval.exp = new LessExpression(yyvsp[-2].exp, yyvsp[0].exp); }
+#line 63 "stella.y"
+{ fprintf(stderr, " <"); yyval.exp = new LessExpression(yyvsp[-2].exp, yyvsp[0].exp); lastExp = yyval.exp; }
     break;
 case 11:
-#line 60 "stella.y"
-{ fprintf(stderr, " >"); yyval.exp = new GreaterExpression(yyvsp[-2].exp, yyvsp[0].exp); }
+#line 64 "stella.y"
+{ fprintf(stderr, " >"); yyval.exp = new GreaterExpression(yyvsp[-2].exp, yyvsp[0].exp); lastExp = yyval.exp; }
     break;
 case 12:
-#line 61 "stella.y"
-{ fprintf(stderr, " >="); yyval.exp = new GreaterEqualsExpression(yyvsp[-2].exp, yyvsp[0].exp); }
+#line 65 "stella.y"
+{ fprintf(stderr, " >="); yyval.exp = new GreaterEqualsExpression(yyvsp[-2].exp, yyvsp[0].exp); lastExp = yyval.exp; }
     break;
 case 13:
-#line 62 "stella.y"
-{ fprintf(stderr, " <="); yyval.exp = new LessEqualsExpression(yyvsp[-2].exp, yyvsp[0].exp); }
+#line 66 "stella.y"
+{ fprintf(stderr, " <="); yyval.exp = new LessEqualsExpression(yyvsp[-2].exp, yyvsp[0].exp); lastExp = yyval.exp; }
     break;
 case 14:
-#line 63 "stella.y"
-{ fprintf(stderr, " !="); yyval.exp = new NotEqualsExpression(yyvsp[-2].exp, yyvsp[0].exp); }
+#line 67 "stella.y"
+{ fprintf(stderr, " !="); yyval.exp = new NotEqualsExpression(yyvsp[-2].exp, yyvsp[0].exp); lastExp = yyval.exp; }
     break;
 case 15:
-#line 64 "stella.y"
-{ fprintf(stderr, " =="); yyval.exp = new EqualsExpression(yyvsp[-2].exp, yyvsp[0].exp); }
+#line 68 "stella.y"
+{ fprintf(stderr, " =="); yyval.exp = new EqualsExpression(yyvsp[-2].exp, yyvsp[0].exp); lastExp = yyval.exp; }
     break;
 case 16:
-#line 65 "stella.y"
-{ fprintf(stderr, " >>"); yyval.exp = new ShiftRightExpression(yyvsp[-2].exp, yyvsp[0].exp); }
+#line 69 "stella.y"
+{ fprintf(stderr, " >>"); yyval.exp = new ShiftRightExpression(yyvsp[-2].exp, yyvsp[0].exp); lastExp = yyval.exp; }
     break;
 case 17:
-#line 66 "stella.y"
-{ fprintf(stderr, " <<"); yyval.exp = new ShiftLeftExpression(yyvsp[-2].exp, yyvsp[0].exp); }
+#line 70 "stella.y"
+{ fprintf(stderr, " <<"); yyval.exp = new ShiftLeftExpression(yyvsp[-2].exp, yyvsp[0].exp); lastExp = yyval.exp; }
     break;
 case 18:
-#line 67 "stella.y"
-{ fprintf(stderr, " ||"); yyval.exp = new LogOrExpression(yyvsp[-2].exp, yyvsp[0].exp); }
+#line 71 "stella.y"
+{ fprintf(stderr, " ||"); yyval.exp = new LogOrExpression(yyvsp[-2].exp, yyvsp[0].exp); lastExp = yyval.exp; }
     break;
 case 19:
-#line 68 "stella.y"
-{ fprintf(stderr, " &&"); yyval.exp = new LogAndExpression(yyvsp[-2].exp, yyvsp[0].exp); }
+#line 72 "stella.y"
+{ fprintf(stderr, " &&"); yyval.exp = new LogAndExpression(yyvsp[-2].exp, yyvsp[0].exp); lastExp = yyval.exp; }
     break;
 case 20:
-#line 69 "stella.y"
-{ fprintf(stderr, " U-"); yyval.exp = new UnaryMinusExpression(yyvsp[0].exp); }
+#line 73 "stella.y"
+{ fprintf(stderr, " U-"); yyval.exp = new UnaryMinusExpression(yyvsp[0].exp); lastExp = yyval.exp; }
     break;
 case 21:
-#line 70 "stella.y"
-{ fprintf(stderr, " ~"); yyval.exp = new BinNotExpression(yyvsp[0].exp); }
+#line 74 "stella.y"
+{ fprintf(stderr, " ~"); yyval.exp = new BinNotExpression(yyvsp[0].exp); lastExp = yyval.exp; }
     break;
 case 22:
-#line 71 "stella.y"
-{ fprintf(stderr, " !"); yyval.exp = new LogNotExpression(yyvsp[0].exp); }
+#line 75 "stella.y"
+{ fprintf(stderr, " !"); yyval.exp = new LogNotExpression(yyvsp[0].exp); lastExp = yyval.exp; }
     break;
 case 23:
-#line 72 "stella.y"
-{ fprintf(stderr, " U*"); yyval.exp = new ByteDerefExpression(yyvsp[0].exp); }
+#line 76 "stella.y"
+{ fprintf(stderr, " U*"); yyval.exp = new ByteDerefExpression(yyvsp[0].exp); lastExp = yyval.exp; }
     break;
 case 24:
-#line 73 "stella.y"
-{ fprintf(stderr, " U@"); yyval.exp = new WordDerefExpression(yyvsp[0].exp); }
+#line 77 "stella.y"
+{ fprintf(stderr, " U@"); yyval.exp = new WordDerefExpression(yyvsp[0].exp); lastExp = yyval.exp; }
     break;
 case 25:
-#line 74 "stella.y"
-{ fprintf(stderr, " U<");  yyval.exp = new LoByteExpression(yyvsp[0].exp);  }
+#line 78 "stella.y"
+{ fprintf(stderr, " U<");  yyval.exp = new LoByteExpression(yyvsp[0].exp);  lastExp = yyval.exp; }
     break;
 case 26:
-#line 75 "stella.y"
-{ fprintf(stderr, " U>");  yyval.exp = new HiByteExpression(yyvsp[0].exp);  }
+#line 79 "stella.y"
+{ fprintf(stderr, " U>");  yyval.exp = new HiByteExpression(yyvsp[0].exp);  lastExp = yyval.exp; }
     break;
 case 27:
-#line 76 "stella.y"
-{ fprintf(stderr, " ()"); yyval.exp = yyvsp[-1].exp; }
+#line 80 "stella.y"
+{ fprintf(stderr, " ()"); yyval.exp = yyvsp[-1].exp; lastExp = yyval.exp; }
     break;
 case 28:
-#line 77 "stella.y"
-{ fprintf(stderr, " %d", yyvsp[0].val); yyval.exp = new ConstExpression(yyvsp[0].val); }
+#line 81 "stella.y"
+{ fprintf(stderr, " %d", yyvsp[0].val); yyval.exp = new ConstExpression(yyvsp[0].val); lastExp = yyval.exp; }
     break;
 case 29:
-#line 78 "stella.y"
-{ fprintf(stderr, " %s", yyvsp[0].equate); yyval.exp = new EquateExpression(yyvsp[0].equate); }
+#line 82 "stella.y"
+{ fprintf(stderr, " %s", yyvsp[0].equate); yyval.exp = new EquateExpression(yyvsp[0].equate); lastExp = yyval.exp; }
     break;
 case 30:
-#line 79 "stella.y"
-{ fprintf(stderr, " (intMethod)"); yyval.exp = new IntMethodExpression(yyvsp[0].intMethod); }
+#line 83 "stella.y"
+{ fprintf(stderr, " (intMethod)"); yyval.exp = new IntMethodExpression(yyvsp[0].intMethod); lastExp = yyval.exp; }
     break;
 case 31:
-#line 80 "stella.y"
-{ fprintf(stderr, " ERR"); yyerror("Invalid label or expression"); return 1; }
+#line 84 "stella.y"
+{ fprintf(stderr, " ERR"); yyerror("Invalid label or constant"); return 1; }
     break;
 }
 
@@ -1304,5 +1308,5 @@ yyreturn:
 #endif
   return yyresult;
 }
-#line 82 "stella.y"
+#line 86 "stella.y"