diff --git a/README.SRC.txt b/README.SRC.txt
index 50e0f76a38..86d9232abc 100644
--- a/README.SRC.txt
+++ b/README.SRC.txt
@@ -31,8 +31,10 @@ Makefile - Makefile for building C interpreter.
 native/ - source code for Factor interpreter written in C.
 library/platform/native - C interpreter-specific code
 f - compiled C interpreter - needs image to run
-boot.image.le - image for x86
-boot.image.be - image for 32-bit SPARC and 32-bit PowerPC
+boot.image.le32 - image for x86
+boot.image.le64 - image for AMD64
+boot.image.be32 - image for 32-bit SPARC and 32-bit PowerPC
+boot.image.be64 - iamge for 64-bit SPARC and 64-bit PowerPC
 
 Notes on the C interpreter
 --------------------------
@@ -40,20 +42,3 @@ Notes on the C interpreter
 When you run the interpreter with a boot image, it loads a
 bunch of files and saves a 'factor.image'. Run the
 interpreter again with this image.
-
-At the moment it assumes a 32-bit architecture. Your C
-compiler's types must be as follows:
-
-short - signed 16 bits
-long - signed 32 bits
-long long - signed 64 bits
-double -IEEE double precision 64-bit float
-
-Moving to 64-bits would require a few changes in the image
-cross-compiler, namely in the way it packs strings.
-
-Not everything has been implemented yet. However, a lot
-already works. Compare the output of this in the C and
-Java interpreters to see how they differ:
-
-"vocabularies" get describe
diff --git a/examples/factoroids.factor b/examples/factoroids.factor
index 335917fd9b..d5f8870586 100644
--- a/examples/factoroids.factor
+++ b/examples/factoroids.factor
@@ -1,5 +1,12 @@
-! Currently the plugin doesn't handle GENERIC: and M:, so we
-! disable the parser. too many errors :sidekick.parser=none:
+! A simple space shooter.
+!
+! To play the game:
+!
+! ./f factor.image -libraries:sdl=libSDL.so -libraries:sdl-gfx=libSDL_gfx.so
+!
+! "examples/oop.factor" run-file
+! "examples/factoroids.factor" run-file
+
 IN: factoroids
 
 USE: combinators
@@ -267,3 +274,6 @@ SYMBOL: event
     ] with-screen ;
 
 factoroids
+
+! Currently the plugin doesn't handle GENERIC: and M:, so we
+! disable the parser. too many errors :sidekick.parser=none:
diff --git a/library/platform/native/debugger.factor b/library/platform/native/debugger.factor
index 4812bf14ca..96b8178b7b 100644
--- a/library/platform/native/debugger.factor
+++ b/library/platform/native/debugger.factor
@@ -94,18 +94,6 @@ USE: words
 : ffi-error ( obj -- )
     "FFI: " write print ;
 
-: datastack-underflow-error ( obj -- )
-    drop "Datastack underflow" print ;
-
-: datastack-overflow-error ( obj -- )
-    drop "Datastack overflow" print ;
-
-: callstack-underflow-error ( obj -- )
-    drop "Callstack underflow" print ;
-
-: callstack-overflow-error ( obj -- )
-    drop "Callstack overflow" print ;
-
 : port-closed-error ( obj -- )
     "Port closed: " write . ;
 
@@ -126,10 +114,6 @@ USE: words
         c-string-error
         ffi-disabled-error
         ffi-error
-        datastack-underflow-error
-        datastack-overflow-error
-        callstack-underflow-error
-        callstack-overflow-error
         port-closed-error
     } vector-nth execute ;
 
diff --git a/native/error.c b/native/error.c
index 131fc59fe6..d10168a95e 100644
--- a/native/error.c
+++ b/native/error.c
@@ -18,9 +18,12 @@ void critical_error(char* msg, CELL tagged)
 	exit(1);
 }
 
-void throw_error(CELL error)
+void throw_error(CELL error, bool keep_stacks)
 {
 	thrown_error = error;
+	thrown_keep_stacks = keep_stacks;
+	thrown_ds = ds;
+	thrown_cs = cs;
 
 	/* Return to run() method */
 	siglongjmp(toplevel,1);
@@ -28,30 +31,32 @@ void throw_error(CELL error)
 
 void primitive_throw(void)
 {
-	throw_error(dpop());
+	throw_error(dpop(),true);
+}
+
+void early_error(CELL error)
+{
+	if(userenv[BREAK_ENV] == F)
+	{
+		/* Crash at startup */
+		fprintf(stderr,"Error %ld thrown before BREAK_ENV set\n",to_fixnum(error));
+		fflush(stderr);
+		exit(1);
+	}
 }
 
 void general_error(CELL error, CELL tagged)
 {
-	CELL c = cons(error,cons(tagged,F));
-	if(userenv[BREAK_ENV] == F)
-	{
-		/* Crash at startup */
-		fprintf(stderr,"Error thrown before BREAK_ENV set\n");
-		fprintf(stderr,"Error #%ld\n",to_fixnum(error));
-		if(error == ERROR_TYPE)
-		{
-			CELL obj = untag_cons(untag_cons(tagged)->cdr)->car;
+	early_error(error);
+	throw_error(cons(error,cons(tagged,F)),true);
+}
 
-			fprintf(stderr,"Type #%ld\n",to_fixnum(
-				untag_cons(tagged)->car));
-			fprintf(stderr,"Object %ld\n",obj);
-			fprintf(stderr,"Got type #%ld\n",type_of(obj));
-		}
-		fflush(stderr);
-		exit(1);
-	}
-	throw_error(c);
+/* It is not safe to access 'ds' from a signal handler, so we just not
+touch it */
+void signal_error(int signal)
+{
+	early_error(ERROR_SIGNAL);
+	throw_error(cons(ERROR_SIGNAL,cons(tag_fixnum(signal),F)),false);
 }
 
 void type_error(CELL type, CELL tagged)
diff --git a/native/error.h b/native/error.h
index 47d1a98170..89d83cd464 100644
--- a/native/error.h
+++ b/native/error.h
@@ -13,21 +13,22 @@
 #define ERROR_C_STRING (12<<3)
 #define ERROR_FFI_DISABLED (13<<3)
 #define ERROR_FFI (14<<3)
-#define ERROR_DATASTACK_UNDERFLOW (15<<3)
-#define ERROR_DATASTACK_OVERFLOW (16<<3)
-#define ERROR_CALLSTACK_UNDERFLOW (17<<3)
-#define ERROR_CALLSTACK_OVERFLOW (18<<3)
-#define ERROR_CLOSED (19<<3)
+#define ERROR_CLOSED (15<<3)
 
 /* When throw_error throws an error, it sets this global and
 longjmps back to the top-level. */
 CELL thrown_error;
+CELL thrown_keep_stacks;
+CELL thrown_ds;
+CELL thrown_cs;
 
 void init_errors(void);
 void fatal_error(char* msg, CELL tagged);
 void critical_error(char* msg, CELL tagged);
-void throw_error(CELL object);
+void throw_error(CELL error, bool keep_stacks);
+void early_error(CELL error);
 void general_error(CELL error, CELL tagged);
+void signal_error(int signal);
 void type_error(CELL type, CELL tagged);
 void primitive_throw(void);
 void range_error(CELL tagged, FIXNUM index, CELL max);
diff --git a/native/run.c b/native/run.c
index 1d7469acc4..c2d94cd70f 100644
--- a/native/run.c
+++ b/native/run.c
@@ -18,7 +18,14 @@ void run(void)
 	sigsetjmp(toplevel, 1);
 	if(thrown_error != F)
 	{
-		fix_stacks();
+		if(thrown_keep_stacks)
+		{
+			ds = thrown_ds;
+			cs = thrown_cs;
+		}
+		else
+			fix_stacks();
+
 		dpush(thrown_error);
 		/* Notify any 'catch' blocks */
 		call(userenv[BREAK_ENV]);
diff --git a/native/signal.c b/native/signal.c
index 402b2d5364..37db15c3c8 100644
--- a/native/signal.c
+++ b/native/signal.c
@@ -2,12 +2,6 @@
 
 void signal_handler(int signal, siginfo_t* siginfo, void* uap)
 {
-	general_error(ERROR_SIGNAL,tag_fixnum(signal));
-}
-
-void memory_signal_handler(int signal, siginfo_t* siginfo, void* uap)
-{
-	fprintf(stderr,"memory signal\n");
 	if(active.here > active.limit)
 	{
 		fprintf(stderr,"Out of memory\n");
@@ -18,7 +12,7 @@ void memory_signal_handler(int signal, siginfo_t* siginfo, void* uap)
 		exit(1);
 	}
 	else
-		general_error(ERROR_SIGNAL,tag_fixnum(signal));
+		signal_error(signal);
 }
 
 /* Called from a signal handler. XXX - is this safe? */
@@ -41,19 +35,16 @@ void init_signals(void)
 {
 	struct sigaction custom_sigaction;
 	struct sigaction profiling_sigaction;
-	struct sigaction memory_sigaction;
 	struct sigaction ign_sigaction;
 	custom_sigaction.sa_sigaction = signal_handler;
 	custom_sigaction.sa_flags = SA_SIGINFO;
 	profiling_sigaction.sa_sigaction = call_profiling_step;
 	profiling_sigaction.sa_flags = SA_SIGINFO;
-	memory_sigaction.sa_sigaction = memory_signal_handler;
-	memory_sigaction.sa_flags = SA_SIGINFO;
 	ign_sigaction.sa_handler = SIG_IGN;
 	sigaction(SIGABRT,&custom_sigaction,NULL);
 	sigaction(SIGFPE,&custom_sigaction,NULL);
-	sigaction(SIGBUS,&memory_sigaction,NULL);
-	sigaction(SIGSEGV,&memory_sigaction,NULL);
+	sigaction(SIGBUS,&custom_sigaction,NULL);
+	sigaction(SIGSEGV,&custom_sigaction,NULL);
 	sigaction(SIGPIPE,&ign_sigaction,NULL);
 	sigaction(SIGPROF,&profiling_sigaction,NULL);
 }