diff --git a/bootstrap/unix-44/Files.c b/bootstrap/unix-44/Files.c
index 81252466..7a06dc47 100644
--- a/bootstrap/unix-44/Files.c
+++ b/bootstrap/unix-44/Files.c
@@ -88,8 +88,7 @@ export void Files_ReadInt (Files_Rider *R, address *R__typ, int16 *x);
 export void Files_ReadLInt (Files_Rider *R, address *R__typ, int32 *x);
 export void Files_ReadLReal (Files_Rider *R, address *R__typ, LONGREAL *x);
 export void Files_ReadLine (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len);
-export void Files_ReadNum (Files_Rider *R, address *R__typ, int32 *x);
-export void Files_ReadNum64 (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len);
+export void Files_ReadNum (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len);
 export void Files_ReadReal (Files_Rider *R, address *R__typ, REAL *x);
 export void Files_ReadSet (Files_Rider *R, address *R__typ, uint32 *x);
 export void Files_ReadString (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len);
@@ -915,15 +914,15 @@ void Files_ReadLine (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len)
 	} while (!b);
 }
 
-void Files_ReadNum64 (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len)
+void Files_ReadNum (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len)
 {
 	int8 s, b;
 	int64 q;
 	s = 0;
 	q = 0;
 	Files_Read(&*R, R__typ, (void*)&b);
-	while ((int16)b >= 128) {
-		q += (int64)__ASH(((int16)b - 128), s);
+	while (b < 0) {
+		q += (int64)__ASH(((int16)b + 128), s);
 		s += 7;
 		Files_Read(&*R, R__typ, (void*)&b);
 	}
@@ -932,23 +931,6 @@ void Files_ReadNum64 (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x
 	__MOVE((address)&q, (address)x, x__len);
 }
 
-void Files_ReadNum (Files_Rider *R, address *R__typ, int32 *x)
-{
-	int8 s;
-	CHAR ch;
-	int32 n;
-	s = 0;
-	n = 0;
-	Files_Read(&*R, R__typ, (void*)&ch);
-	while ((int16)ch >= 128) {
-		n += __ASH(((int16)ch - 128), s);
-		s += 7;
-		Files_Read(&*R, R__typ, (void*)&ch);
-	}
-	n += __ASH((__MASK((int16)ch, -64) - __ASHL(__ASHR((int16)ch, 6), 6)), s);
-	*x = n;
-}
-
 void Files_WriteBool (Files_Rider *R, address *R__typ, BOOLEAN x)
 {
 	Files_Write(&*R, R__typ, __VAL(CHAR, x));
diff --git a/bootstrap/unix-44/Files.h b/bootstrap/unix-44/Files.h
index af64d06f..69903ae1 100644
--- a/bootstrap/unix-44/Files.h
+++ b/bootstrap/unix-44/Files.h
@@ -45,8 +45,7 @@ import void Files_ReadInt (Files_Rider *R, address *R__typ, int16 *x);
 import void Files_ReadLInt (Files_Rider *R, address *R__typ, int32 *x);
 import void Files_ReadLReal (Files_Rider *R, address *R__typ, LONGREAL *x);
 import void Files_ReadLine (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len);
-import void Files_ReadNum (Files_Rider *R, address *R__typ, int32 *x);
-import void Files_ReadNum64 (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len);
+import void Files_ReadNum (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len);
 import void Files_ReadReal (Files_Rider *R, address *R__typ, REAL *x);
 import void Files_ReadSet (Files_Rider *R, address *R__typ, uint32 *x);
 import void Files_ReadString (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len);
diff --git a/bootstrap/unix-44/OPM.c b/bootstrap/unix-44/OPM.c
index 7e770a33..1457a09c 100644
--- a/bootstrap/unix-44/OPM.c
+++ b/bootstrap/unix-44/OPM.c
@@ -745,7 +745,7 @@ int32 OPM_SymRInt (void)
 {
 	int32 _o_result;
 	int32 k;
-	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, &k);
+	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&k, 4);
 	_o_result = k;
 	return _o_result;
 }
@@ -754,19 +754,19 @@ int64 OPM_SymRInt64 (void)
 {
 	int64 _o_result;
 	int64 k;
-	Files_ReadNum64(&OPM_oldSF, Files_Rider__typ, (void*)&k, 8);
+	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&k, 8);
 	_o_result = k;
 	return _o_result;
 }
 
 void OPM_SymRSet64 (uint64 *s)
 {
-	Files_ReadNum64(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 8);
+	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 8);
 }
 
 void OPM_SymRSet (uint32 *s)
 {
-	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (int32*)&*s);
+	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 4);
 }
 
 void OPM_SymRReal (REAL *r)
diff --git a/bootstrap/unix-44/extTools.c b/bootstrap/unix-44/extTools.c
index fe7eb545..b082e82c 100644
--- a/bootstrap/unix-44/extTools.c
+++ b/bootstrap/unix-44/extTools.c
@@ -64,7 +64,7 @@ static void extTools_execute (CHAR *title, LONGINT title__len, CHAR *cmd, LONGIN
 
 static void extTools_InitialiseCompilerCommand (CHAR *s, LONGINT s__len)
 {
-	__COPY("gcc -g -O1", s, s__len);
+	__COPY("gcc -g", s, s__len);
 	Strings_Append((CHAR*)" -I \"", 6, (void*)s, s__len);
 	Strings_Append(OPM_ResourceDir, 1024, (void*)s, s__len);
 	Strings_Append((CHAR*)"/include\" ", 11, (void*)s, s__len);
diff --git a/bootstrap/unix-48/Files.c b/bootstrap/unix-48/Files.c
index 81252466..7a06dc47 100644
--- a/bootstrap/unix-48/Files.c
+++ b/bootstrap/unix-48/Files.c
@@ -88,8 +88,7 @@ export void Files_ReadInt (Files_Rider *R, address *R__typ, int16 *x);
 export void Files_ReadLInt (Files_Rider *R, address *R__typ, int32 *x);
 export void Files_ReadLReal (Files_Rider *R, address *R__typ, LONGREAL *x);
 export void Files_ReadLine (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len);
-export void Files_ReadNum (Files_Rider *R, address *R__typ, int32 *x);
-export void Files_ReadNum64 (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len);
+export void Files_ReadNum (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len);
 export void Files_ReadReal (Files_Rider *R, address *R__typ, REAL *x);
 export void Files_ReadSet (Files_Rider *R, address *R__typ, uint32 *x);
 export void Files_ReadString (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len);
@@ -915,15 +914,15 @@ void Files_ReadLine (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len)
 	} while (!b);
 }
 
-void Files_ReadNum64 (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len)
+void Files_ReadNum (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len)
 {
 	int8 s, b;
 	int64 q;
 	s = 0;
 	q = 0;
 	Files_Read(&*R, R__typ, (void*)&b);
-	while ((int16)b >= 128) {
-		q += (int64)__ASH(((int16)b - 128), s);
+	while (b < 0) {
+		q += (int64)__ASH(((int16)b + 128), s);
 		s += 7;
 		Files_Read(&*R, R__typ, (void*)&b);
 	}
@@ -932,23 +931,6 @@ void Files_ReadNum64 (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x
 	__MOVE((address)&q, (address)x, x__len);
 }
 
-void Files_ReadNum (Files_Rider *R, address *R__typ, int32 *x)
-{
-	int8 s;
-	CHAR ch;
-	int32 n;
-	s = 0;
-	n = 0;
-	Files_Read(&*R, R__typ, (void*)&ch);
-	while ((int16)ch >= 128) {
-		n += __ASH(((int16)ch - 128), s);
-		s += 7;
-		Files_Read(&*R, R__typ, (void*)&ch);
-	}
-	n += __ASH((__MASK((int16)ch, -64) - __ASHL(__ASHR((int16)ch, 6), 6)), s);
-	*x = n;
-}
-
 void Files_WriteBool (Files_Rider *R, address *R__typ, BOOLEAN x)
 {
 	Files_Write(&*R, R__typ, __VAL(CHAR, x));
diff --git a/bootstrap/unix-48/Files.h b/bootstrap/unix-48/Files.h
index af64d06f..69903ae1 100644
--- a/bootstrap/unix-48/Files.h
+++ b/bootstrap/unix-48/Files.h
@@ -45,8 +45,7 @@ import void Files_ReadInt (Files_Rider *R, address *R__typ, int16 *x);
 import void Files_ReadLInt (Files_Rider *R, address *R__typ, int32 *x);
 import void Files_ReadLReal (Files_Rider *R, address *R__typ, LONGREAL *x);
 import void Files_ReadLine (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len);
-import void Files_ReadNum (Files_Rider *R, address *R__typ, int32 *x);
-import void Files_ReadNum64 (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len);
+import void Files_ReadNum (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len);
 import void Files_ReadReal (Files_Rider *R, address *R__typ, REAL *x);
 import void Files_ReadSet (Files_Rider *R, address *R__typ, uint32 *x);
 import void Files_ReadString (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len);
diff --git a/bootstrap/unix-48/OPM.c b/bootstrap/unix-48/OPM.c
index 7e770a33..1457a09c 100644
--- a/bootstrap/unix-48/OPM.c
+++ b/bootstrap/unix-48/OPM.c
@@ -745,7 +745,7 @@ int32 OPM_SymRInt (void)
 {
 	int32 _o_result;
 	int32 k;
-	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, &k);
+	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&k, 4);
 	_o_result = k;
 	return _o_result;
 }
@@ -754,19 +754,19 @@ int64 OPM_SymRInt64 (void)
 {
 	int64 _o_result;
 	int64 k;
-	Files_ReadNum64(&OPM_oldSF, Files_Rider__typ, (void*)&k, 8);
+	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&k, 8);
 	_o_result = k;
 	return _o_result;
 }
 
 void OPM_SymRSet64 (uint64 *s)
 {
-	Files_ReadNum64(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 8);
+	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 8);
 }
 
 void OPM_SymRSet (uint32 *s)
 {
-	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (int32*)&*s);
+	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 4);
 }
 
 void OPM_SymRReal (REAL *r)
diff --git a/bootstrap/unix-48/extTools.c b/bootstrap/unix-48/extTools.c
index fe7eb545..b082e82c 100644
--- a/bootstrap/unix-48/extTools.c
+++ b/bootstrap/unix-48/extTools.c
@@ -64,7 +64,7 @@ static void extTools_execute (CHAR *title, LONGINT title__len, CHAR *cmd, LONGIN
 
 static void extTools_InitialiseCompilerCommand (CHAR *s, LONGINT s__len)
 {
-	__COPY("gcc -g -O1", s, s__len);
+	__COPY("gcc -g", s, s__len);
 	Strings_Append((CHAR*)" -I \"", 6, (void*)s, s__len);
 	Strings_Append(OPM_ResourceDir, 1024, (void*)s, s__len);
 	Strings_Append((CHAR*)"/include\" ", 11, (void*)s, s__len);
diff --git a/bootstrap/unix-88/Files.c b/bootstrap/unix-88/Files.c
index 75dee180..a884abf3 100644
--- a/bootstrap/unix-88/Files.c
+++ b/bootstrap/unix-88/Files.c
@@ -88,8 +88,7 @@ export void Files_ReadInt (Files_Rider *R, address *R__typ, int16 *x);
 export void Files_ReadLInt (Files_Rider *R, address *R__typ, int32 *x);
 export void Files_ReadLReal (Files_Rider *R, address *R__typ, LONGREAL *x);
 export void Files_ReadLine (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len);
-export void Files_ReadNum (Files_Rider *R, address *R__typ, int32 *x);
-export void Files_ReadNum64 (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len);
+export void Files_ReadNum (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len);
 export void Files_ReadReal (Files_Rider *R, address *R__typ, REAL *x);
 export void Files_ReadSet (Files_Rider *R, address *R__typ, uint32 *x);
 export void Files_ReadString (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len);
@@ -915,15 +914,15 @@ void Files_ReadLine (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len)
 	} while (!b);
 }
 
-void Files_ReadNum64 (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len)
+void Files_ReadNum (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len)
 {
 	int8 s, b;
 	int64 q;
 	s = 0;
 	q = 0;
 	Files_Read(&*R, R__typ, (void*)&b);
-	while ((int16)b >= 128) {
-		q += (int64)__ASH(((int16)b - 128), s);
+	while (b < 0) {
+		q += (int64)__ASH(((int16)b + 128), s);
 		s += 7;
 		Files_Read(&*R, R__typ, (void*)&b);
 	}
@@ -932,23 +931,6 @@ void Files_ReadNum64 (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x
 	__MOVE((address)&q, (address)x, x__len);
 }
 
-void Files_ReadNum (Files_Rider *R, address *R__typ, int32 *x)
-{
-	int8 s;
-	CHAR ch;
-	int32 n;
-	s = 0;
-	n = 0;
-	Files_Read(&*R, R__typ, (void*)&ch);
-	while ((int16)ch >= 128) {
-		n += __ASH(((int16)ch - 128), s);
-		s += 7;
-		Files_Read(&*R, R__typ, (void*)&ch);
-	}
-	n += __ASH((__MASK((int16)ch, -64) - __ASHL(__ASHR((int16)ch, 6), 6)), s);
-	*x = n;
-}
-
 void Files_WriteBool (Files_Rider *R, address *R__typ, BOOLEAN x)
 {
 	Files_Write(&*R, R__typ, __VAL(CHAR, x));
diff --git a/bootstrap/unix-88/Files.h b/bootstrap/unix-88/Files.h
index 0ba00834..02e44bed 100644
--- a/bootstrap/unix-88/Files.h
+++ b/bootstrap/unix-88/Files.h
@@ -47,8 +47,7 @@ import void Files_ReadInt (Files_Rider *R, address *R__typ, int16 *x);
 import void Files_ReadLInt (Files_Rider *R, address *R__typ, int32 *x);
 import void Files_ReadLReal (Files_Rider *R, address *R__typ, LONGREAL *x);
 import void Files_ReadLine (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len);
-import void Files_ReadNum (Files_Rider *R, address *R__typ, int32 *x);
-import void Files_ReadNum64 (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len);
+import void Files_ReadNum (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len);
 import void Files_ReadReal (Files_Rider *R, address *R__typ, REAL *x);
 import void Files_ReadSet (Files_Rider *R, address *R__typ, uint32 *x);
 import void Files_ReadString (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len);
diff --git a/bootstrap/unix-88/OPM.c b/bootstrap/unix-88/OPM.c
index deeaaa1d..0c2ad2b1 100644
--- a/bootstrap/unix-88/OPM.c
+++ b/bootstrap/unix-88/OPM.c
@@ -745,7 +745,7 @@ int32 OPM_SymRInt (void)
 {
 	int32 _o_result;
 	int32 k;
-	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, &k);
+	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&k, 4);
 	_o_result = k;
 	return _o_result;
 }
@@ -754,19 +754,19 @@ int64 OPM_SymRInt64 (void)
 {
 	int64 _o_result;
 	int64 k;
-	Files_ReadNum64(&OPM_oldSF, Files_Rider__typ, (void*)&k, 8);
+	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&k, 8);
 	_o_result = k;
 	return _o_result;
 }
 
 void OPM_SymRSet64 (uint64 *s)
 {
-	Files_ReadNum64(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 8);
+	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 8);
 }
 
 void OPM_SymRSet (uint32 *s)
 {
-	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (int32*)&*s);
+	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 4);
 }
 
 void OPM_SymRReal (REAL *r)
diff --git a/bootstrap/unix-88/extTools.c b/bootstrap/unix-88/extTools.c
index fe7eb545..b082e82c 100644
--- a/bootstrap/unix-88/extTools.c
+++ b/bootstrap/unix-88/extTools.c
@@ -64,7 +64,7 @@ static void extTools_execute (CHAR *title, LONGINT title__len, CHAR *cmd, LONGIN
 
 static void extTools_InitialiseCompilerCommand (CHAR *s, LONGINT s__len)
 {
-	__COPY("gcc -g -O1", s, s__len);
+	__COPY("gcc -g", s, s__len);
 	Strings_Append((CHAR*)" -I \"", 6, (void*)s, s__len);
 	Strings_Append(OPM_ResourceDir, 1024, (void*)s, s__len);
 	Strings_Append((CHAR*)"/include\" ", 11, (void*)s, s__len);
diff --git a/bootstrap/windows-48/Files.c b/bootstrap/windows-48/Files.c
index 003173fa..6163931f 100644
--- a/bootstrap/windows-48/Files.c
+++ b/bootstrap/windows-48/Files.c
@@ -88,8 +88,7 @@ export void Files_ReadInt (Files_Rider *R, address *R__typ, int16 *x);
 export void Files_ReadLInt (Files_Rider *R, address *R__typ, int32 *x);
 export void Files_ReadLReal (Files_Rider *R, address *R__typ, LONGREAL *x);
 export void Files_ReadLine (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len);
-export void Files_ReadNum (Files_Rider *R, address *R__typ, int32 *x);
-export void Files_ReadNum64 (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len);
+export void Files_ReadNum (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len);
 export void Files_ReadReal (Files_Rider *R, address *R__typ, REAL *x);
 export void Files_ReadSet (Files_Rider *R, address *R__typ, uint32 *x);
 export void Files_ReadString (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len);
@@ -915,15 +914,15 @@ void Files_ReadLine (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len)
 	} while (!b);
 }
 
-void Files_ReadNum64 (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len)
+void Files_ReadNum (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len)
 {
 	int8 s, b;
 	int64 q;
 	s = 0;
 	q = 0;
 	Files_Read(&*R, R__typ, (void*)&b);
-	while ((int16)b >= 128) {
-		q += (int64)__ASH(((int16)b - 128), s);
+	while (b < 0) {
+		q += (int64)__ASH(((int16)b + 128), s);
 		s += 7;
 		Files_Read(&*R, R__typ, (void*)&b);
 	}
@@ -932,23 +931,6 @@ void Files_ReadNum64 (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x
 	__MOVE((address)&q, (address)x, x__len);
 }
 
-void Files_ReadNum (Files_Rider *R, address *R__typ, int32 *x)
-{
-	int8 s;
-	CHAR ch;
-	int32 n;
-	s = 0;
-	n = 0;
-	Files_Read(&*R, R__typ, (void*)&ch);
-	while ((int16)ch >= 128) {
-		n += __ASH(((int16)ch - 128), s);
-		s += 7;
-		Files_Read(&*R, R__typ, (void*)&ch);
-	}
-	n += __ASH((__MASK((int16)ch, -64) - __ASHL(__ASHR((int16)ch, 6), 6)), s);
-	*x = n;
-}
-
 void Files_WriteBool (Files_Rider *R, address *R__typ, BOOLEAN x)
 {
 	Files_Write(&*R, R__typ, __VAL(CHAR, x));
diff --git a/bootstrap/windows-48/Files.h b/bootstrap/windows-48/Files.h
index 12fa2cfa..56c229a3 100644
--- a/bootstrap/windows-48/Files.h
+++ b/bootstrap/windows-48/Files.h
@@ -45,8 +45,7 @@ import void Files_ReadInt (Files_Rider *R, address *R__typ, int16 *x);
 import void Files_ReadLInt (Files_Rider *R, address *R__typ, int32 *x);
 import void Files_ReadLReal (Files_Rider *R, address *R__typ, LONGREAL *x);
 import void Files_ReadLine (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len);
-import void Files_ReadNum (Files_Rider *R, address *R__typ, int32 *x);
-import void Files_ReadNum64 (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len);
+import void Files_ReadNum (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len);
 import void Files_ReadReal (Files_Rider *R, address *R__typ, REAL *x);
 import void Files_ReadSet (Files_Rider *R, address *R__typ, uint32 *x);
 import void Files_ReadString (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len);
diff --git a/bootstrap/windows-48/OPM.c b/bootstrap/windows-48/OPM.c
index 7e770a33..1457a09c 100644
--- a/bootstrap/windows-48/OPM.c
+++ b/bootstrap/windows-48/OPM.c
@@ -745,7 +745,7 @@ int32 OPM_SymRInt (void)
 {
 	int32 _o_result;
 	int32 k;
-	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, &k);
+	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&k, 4);
 	_o_result = k;
 	return _o_result;
 }
@@ -754,19 +754,19 @@ int64 OPM_SymRInt64 (void)
 {
 	int64 _o_result;
 	int64 k;
-	Files_ReadNum64(&OPM_oldSF, Files_Rider__typ, (void*)&k, 8);
+	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&k, 8);
 	_o_result = k;
 	return _o_result;
 }
 
 void OPM_SymRSet64 (uint64 *s)
 {
-	Files_ReadNum64(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 8);
+	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 8);
 }
 
 void OPM_SymRSet (uint32 *s)
 {
-	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (int32*)&*s);
+	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 4);
 }
 
 void OPM_SymRReal (REAL *r)
diff --git a/bootstrap/windows-48/extTools.c b/bootstrap/windows-48/extTools.c
index fe7eb545..b082e82c 100644
--- a/bootstrap/windows-48/extTools.c
+++ b/bootstrap/windows-48/extTools.c
@@ -64,7 +64,7 @@ static void extTools_execute (CHAR *title, LONGINT title__len, CHAR *cmd, LONGIN
 
 static void extTools_InitialiseCompilerCommand (CHAR *s, LONGINT s__len)
 {
-	__COPY("gcc -g -O1", s, s__len);
+	__COPY("gcc -g", s, s__len);
 	Strings_Append((CHAR*)" -I \"", 6, (void*)s, s__len);
 	Strings_Append(OPM_ResourceDir, 1024, (void*)s, s__len);
 	Strings_Append((CHAR*)"/include\" ", 11, (void*)s, s__len);
diff --git a/bootstrap/windows-88/Files.c b/bootstrap/windows-88/Files.c
index 36fc4d53..ff0e4a78 100644
--- a/bootstrap/windows-88/Files.c
+++ b/bootstrap/windows-88/Files.c
@@ -88,8 +88,7 @@ export void Files_ReadInt (Files_Rider *R, address *R__typ, int16 *x);
 export void Files_ReadLInt (Files_Rider *R, address *R__typ, int32 *x);
 export void Files_ReadLReal (Files_Rider *R, address *R__typ, LONGREAL *x);
 export void Files_ReadLine (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len);
-export void Files_ReadNum (Files_Rider *R, address *R__typ, int32 *x);
-export void Files_ReadNum64 (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len);
+export void Files_ReadNum (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len);
 export void Files_ReadReal (Files_Rider *R, address *R__typ, REAL *x);
 export void Files_ReadSet (Files_Rider *R, address *R__typ, uint32 *x);
 export void Files_ReadString (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len);
@@ -915,15 +914,15 @@ void Files_ReadLine (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len)
 	} while (!b);
 }
 
-void Files_ReadNum64 (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len)
+void Files_ReadNum (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len)
 {
 	int8 s, b;
 	int64 q;
 	s = 0;
 	q = 0;
 	Files_Read(&*R, R__typ, (void*)&b);
-	while ((int16)b >= 128) {
-		q += (int64)__ASH(((int16)b - 128), s);
+	while (b < 0) {
+		q += (int64)__ASH(((int16)b + 128), s);
 		s += 7;
 		Files_Read(&*R, R__typ, (void*)&b);
 	}
@@ -932,23 +931,6 @@ void Files_ReadNum64 (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x
 	__MOVE((address)&q, (address)x, x__len);
 }
 
-void Files_ReadNum (Files_Rider *R, address *R__typ, int32 *x)
-{
-	int8 s;
-	CHAR ch;
-	int32 n;
-	s = 0;
-	n = 0;
-	Files_Read(&*R, R__typ, (void*)&ch);
-	while ((int16)ch >= 128) {
-		n += __ASH(((int16)ch - 128), s);
-		s += 7;
-		Files_Read(&*R, R__typ, (void*)&ch);
-	}
-	n += __ASH((__MASK((int16)ch, -64) - __ASHL(__ASHR((int16)ch, 6), 6)), s);
-	*x = n;
-}
-
 void Files_WriteBool (Files_Rider *R, address *R__typ, BOOLEAN x)
 {
 	Files_Write(&*R, R__typ, __VAL(CHAR, x));
diff --git a/bootstrap/windows-88/Files.h b/bootstrap/windows-88/Files.h
index 35d709e7..e00e603f 100644
--- a/bootstrap/windows-88/Files.h
+++ b/bootstrap/windows-88/Files.h
@@ -47,8 +47,7 @@ import void Files_ReadInt (Files_Rider *R, address *R__typ, int16 *x);
 import void Files_ReadLInt (Files_Rider *R, address *R__typ, int32 *x);
 import void Files_ReadLReal (Files_Rider *R, address *R__typ, LONGREAL *x);
 import void Files_ReadLine (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len);
-import void Files_ReadNum (Files_Rider *R, address *R__typ, int32 *x);
-import void Files_ReadNum64 (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len);
+import void Files_ReadNum (Files_Rider *R, address *R__typ, SYSTEM_BYTE *x, LONGINT x__len);
 import void Files_ReadReal (Files_Rider *R, address *R__typ, REAL *x);
 import void Files_ReadSet (Files_Rider *R, address *R__typ, uint32 *x);
 import void Files_ReadString (Files_Rider *R, address *R__typ, CHAR *x, LONGINT x__len);
diff --git a/bootstrap/windows-88/OPM.c b/bootstrap/windows-88/OPM.c
index deeaaa1d..0c2ad2b1 100644
--- a/bootstrap/windows-88/OPM.c
+++ b/bootstrap/windows-88/OPM.c
@@ -745,7 +745,7 @@ int32 OPM_SymRInt (void)
 {
 	int32 _o_result;
 	int32 k;
-	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, &k);
+	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&k, 4);
 	_o_result = k;
 	return _o_result;
 }
@@ -754,19 +754,19 @@ int64 OPM_SymRInt64 (void)
 {
 	int64 _o_result;
 	int64 k;
-	Files_ReadNum64(&OPM_oldSF, Files_Rider__typ, (void*)&k, 8);
+	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&k, 8);
 	_o_result = k;
 	return _o_result;
 }
 
 void OPM_SymRSet64 (uint64 *s)
 {
-	Files_ReadNum64(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 8);
+	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 8);
 }
 
 void OPM_SymRSet (uint32 *s)
 {
-	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (int32*)&*s);
+	Files_ReadNum(&OPM_oldSF, Files_Rider__typ, (void*)&*s, 4);
 }
 
 void OPM_SymRReal (REAL *r)
diff --git a/bootstrap/windows-88/extTools.c b/bootstrap/windows-88/extTools.c
index fe7eb545..b082e82c 100644
--- a/bootstrap/windows-88/extTools.c
+++ b/bootstrap/windows-88/extTools.c
@@ -64,7 +64,7 @@ static void extTools_execute (CHAR *title, LONGINT title__len, CHAR *cmd, LONGIN
 
 static void extTools_InitialiseCompilerCommand (CHAR *s, LONGINT s__len)
 {
-	__COPY("gcc -g -O1", s, s__len);
+	__COPY("gcc -g", s, s__len);
 	Strings_Append((CHAR*)" -I \"", 6, (void*)s, s__len);
 	Strings_Append(OPM_ResourceDir, 1024, (void*)s, s__len);
 	Strings_Append((CHAR*)"/include\" ", 11, (void*)s, s__len);
diff --git a/src/compiler/OPM.Mod b/src/compiler/OPM.Mod
index 6db573f6..a2beb450 100644
--- a/src/compiler/OPM.Mod
+++ b/src/compiler/OPM.Mod
@@ -600,16 +600,16 @@ MODULE OPM;  (* RC 6.3.89 / 28.6.89, J.Templ 10.7.89 / 22.7.96  *)
 
   PROCEDURE SymRInt64*(): SYSTEM.INT64;
     VAR k: SYSTEM.INT64;
-  BEGIN Files.ReadNum64(oldSF, k); RETURN k
+  BEGIN Files.ReadNum(oldSF, k); RETURN k
   END SymRInt64;
 
   (* todo - combine RSet64 and RSet *)
   PROCEDURE SymRSet64*(VAR s: SYSTEM.SET64);
-  BEGIN Files.ReadNum64(oldSF, s)
+  BEGIN Files.ReadNum(oldSF, s)
   END SymRSet64;
 
   PROCEDURE SymRSet*(VAR s: SET);
-  BEGIN Files.ReadNum(oldSF, SYSTEM.VAL(LONGINT, s))
+  BEGIN Files.ReadNum(oldSF, s)
   END SymRSet;
 
   PROCEDURE SymRReal*(VAR r: REAL);
diff --git a/src/runtime/Files.Mod b/src/runtime/Files.Mod
index 893abf1f..a8246ace 100644
--- a/src/runtime/Files.Mod
+++ b/src/runtime/Files.Mod
@@ -657,7 +657,7 @@ Especially Length would become fairly complex.
   PROCEDURE ReadNum*(VAR R: Rider; VAR x: ARRAY OF SYSTEM.BYTE);
     VAR s, b: SYSTEM.INT8; q: SYSTEM.INT64;
   BEGIN s := 0; q := 0; Read(R, b);
-    WHILE b >= 128 DO INC(q, ASH(b-128, s)); INC(s, 7); Read(R, b) END;
+    WHILE b < 0 DO INC(q, ASH(b+128, s)); INC(s, 7); Read(R, b) END;
     INC(q, ASH(b MOD 64 - b DIV 64 * 64, s));
     ASSERT(LEN(x) <= 8);
     SYSTEM.MOVE(SYSTEM.ADR(q), SYSTEM.ADR(x), LEN(x))  (* Assumes little endian representation of q and x. *)
diff --git a/src/system/Files.Mod b/src/system/Files.Mod
index 94ef014a..e4add256 100644
--- a/src/system/Files.Mod
+++ b/src/system/Files.Mod
@@ -654,23 +654,14 @@ Especially Length would become fairly complex.
     UNTIL b
   END ReadLine;
 
-  (* todo combine ReadNum and ReadNum64 *)
-  PROCEDURE ReadNum64*(VAR R: Rider; VAR x: ARRAY OF SYSTEM.BYTE);
+  PROCEDURE ReadNum*(VAR R: Rider; VAR x: ARRAY OF SYSTEM.BYTE);
     VAR s, b: SYSTEM.INT8; q: SYSTEM.INT64;
-  BEGIN s := 0; q := 0; Read(R, b);
-    WHILE b >= 128 DO INC(q, ASH(b-128, s)); INC(s, 7); Read(R, b) END;
+  BEGIN
+    s := 0; q := 0; Read(R, b);
+    WHILE b < 0 DO INC(q, ASH(b+128, s)); INC(s, 7); Read(R, b) END;
     INC(q, ASH(b MOD 64 - b DIV 64 * 64, s));
     ASSERT(LEN(x) <= 8);
     SYSTEM.MOVE(SYSTEM.ADR(q), SYSTEM.ADR(x), LEN(x))  (* Assumes little endian representation of q and x. *)
-  END ReadNum64;
-
-
-  PROCEDURE ReadNum* (VAR R: Rider; VAR x: LONGINT);
-    VAR s: SHORTINT; ch: CHAR; n: LONGINT;
-  BEGIN s := 0; n := 0; Read(R, ch);
-    WHILE ORD(ch) >= 128 DO INC(n, ASH(ORD(ch) - 128, s) ); INC(s, 7); Read(R, ch) END;
-    INC(n, ASH(ORD(ch) MOD 64 - ORD(ch) DIV 64 * 64, s) );
-    x := n
   END ReadNum;
 
   PROCEDURE WriteBool* (VAR R: Rider; x: BOOLEAN);
diff --git a/src/tools/make/configure.c b/src/tools/make/configure.c
index b8d261dd..d3ccc2d1 100644
--- a/src/tools/make/configure.c
+++ b/src/tools/make/configure.c
@@ -126,7 +126,7 @@ void determineOS() {
   #endif
 }
 
-#define optimize " -O1"
+#define optimize "" // " -O1"
 
 void determineCCompiler() {
   snprintf(libspec, sizeof(libspec), " -l %s", oname);