diff --git a/lang/cem/cemcom/BigPars b/lang/cem/cemcom/BigPars
index 1c3888eb0..eeacd0564 100644
--- a/lang/cem/cemcom/BigPars
+++ b/lang/cem/cemcom/BigPars
@@ -1,5 +1,5 @@
 !File: lint.h
-#undef	LINT		1	/* if defined, 'lint' is produced	*/
+/*#define	LINT		1	/* if defined, 'lint' is produced	*/
 
 
 !File: pathlength.h
@@ -75,7 +75,7 @@
 
 
 !File: botch_free.h
-#undef BOTCH_FREE	1	/* when defined, botch freed memory, as a check	*/
+/*#define BOTCH_FREE	1	/* when defined, botch freed memory, as a check	*/
 
 
 !File: dataflow.h
@@ -83,7 +83,7 @@
 
 
 !File: debug.h
-#undef DEBUG		1	/* perform various self-tests		*/
+/*#define DEBUG		1	/* perform various self-tests		*/
 
 
 !File: use_tmp.h
@@ -112,16 +112,16 @@
 
 
 !File: nopp.h
-#undef NOPP		1	/* if NOT defined, use built-int preprocessor */
+/*#define NOPP		1	/* if NOT defined, use built-int preprocessor */
 
 
 !File: nobitfield.h
-#undef NOBITFIELD	1	/* if NOT defined, implement bitfields	*/
+/*#define NOBITFIELD	1	/* if NOT defined, implement bitfields	*/
 
 
 !File: spec_arith.h
 /* describes internal compiler arithmetics */
-#undef	SPECIAL_ARITHMETICS	/* something different from native long */
+/*#define	SPECIAL_ARITHMETICS	/* something different from native long */
 
 
 !File: static.h
@@ -129,19 +129,19 @@
 
 
 !File: nofloat.h
-#undef NOFLOAT		1	/* if NOT defined, floats are implemented */
+/*#define NOFLOAT		1	/* if NOT defined, floats are implemented */
 
 
 !File: noRoption.h
-#undef NOROPTION	1	/* if NOT defined, R option is implemented */
+/*#define NOROPTION	1	/* if NOT defined, R option is implemented */
 
 
 !File: nocross.h
-#undef NOCROSS		1	/* if NOT defined, cross compiler */
+/*#define NOCROSS		1	/* if NOT defined, cross compiler */
 
 
 !File: regcount.h
-#undef REGCOUNT		1	/* count occurrences for register messages */
+/*#define REGCOUNT		1	/* count occurrences for register messages */
 
 !File: dbsymtab.h
 #define DBSYMTAB	1	/* ability to produce symbol table for debugger
diff --git a/lang/cem/cemcom/SmallPars b/lang/cem/cemcom/SmallPars
index c50f1ad44..ec0df8e77 100644
--- a/lang/cem/cemcom/SmallPars
+++ b/lang/cem/cemcom/SmallPars
@@ -1,5 +1,5 @@
 !File: lint.h
-#undef	LINT		1	/* if defined, 'lint' is produced	*/
+/*#define	LINT		1	/* if defined, 'lint' is produced	*/
 
 
 !File: pathlength.h
@@ -75,23 +75,23 @@
 
 
 !File: botch_free.h
-#undef BOTCH_FREE	1	/* when defined, botch freed memory, as a check	*/
+/*#define BOTCH_FREE	1	/* when defined, botch freed memory, as a check	*/
 
 
 !File: dataflow.h
-#undef DATAFLOW	1	/* produce some compile-time xref	*/
+/*#define DATAFLOW	1	/* produce some compile-time xref	*/
 
 
 !File: debug.h
-#undef DEBUG		1	/* perform various self-tests		*/
+/*#define DEBUG		1	/* perform various self-tests		*/
 
 
 !File: use_tmp.h
-#undef PREPEND_SCOPES	1	/* collect exa, exp, ina and inp commands
+/*#define PREPEND_SCOPES	1	/* collect exa, exp, ina and inp commands
 					and if USE_TMP is defined let them
 					precede the rest of the generated
 					compact code	*/
-#undef USE_TMP		1	/* use C_insertpart, C_endpart mechanism
+/*#define USE_TMP		1	/* use C_insertpart, C_endpart mechanism
 					to generate EM-code in the order needed
 					for the code-generators. If not defined,
 					the old-style peephole optimizer is
@@ -108,7 +108,7 @@
 
 
 !File: inputtype.h
-#undef INP_READ_IN_ONE	1	/* read input file in one	*/
+/*#define INP_READ_IN_ONE	1	/* read input file in one	*/
 
 
 !File: nopp.h
@@ -116,12 +116,12 @@
 
 
 !File: nobitfield.h
-#undef NOBITFIELD	1	/* if NOT defined, implement bitfields	*/
+/*#define NOBITFIELD	1	/* if NOT defined, implement bitfields	*/
 
 
 !File: spec_arith.h
 /* describes internal compiler arithmetics */
-#undef	SPECIAL_ARITHMETICS	/* something different from native long */
+/*#define	SPECIAL_ARITHMETICS	/* something different from native long */
 
 
 !File: static.h
@@ -129,7 +129,7 @@
 
 
 !File: nofloat.h
-#undef NOFLOAT		1	/* if NOT defined, floats are implemented */
+/*#define NOFLOAT		1	/* if NOT defined, floats are implemented */
 
 
 !File: noRoption.h
@@ -137,15 +137,15 @@
 
 
 !File: nocross.h
-#undef NOCROSS		1	/* if NOT defined, cross compiler */
+/*#define NOCROSS		1	/* if NOT defined, cross compiler */
 
 
 !File: regcount.h
-#undef REGCOUNT		1	/* count occurrences for register messages */
+/*#define REGCOUNT		1	/* count occurrences for register messages */
 
 
 !File: dbsymtab.h
-#undef DBSYMTAB		1	/* ability to produce symbol table for debugger
+/*#define DBSYMTAB		1	/* ability to produce symbol table for debugger
 */
 
 
diff --git a/lang/cem/lint/lpass1.ansi/Parameters b/lang/cem/lint/lpass1.ansi/Parameters
index 46f66e2a8..e93a550d2 100644
--- a/lang/cem/lint/lpass1.ansi/Parameters
+++ b/lang/cem/lint/lpass1.ansi/Parameters
@@ -76,23 +76,23 @@
 
 
 !File: botch_free.h
-#undef BOTCH_FREE	1	/* when defined, botch freed memory, as a check	*/
+/*#define BOTCH_FREE	1	/* when defined, botch freed memory, as a check	*/
 
 
 !File: dataflow.h
-#undef	DATAFLOW	1	/* produce some compile-time xref	*/
+/*#define	DATAFLOW	1	/* produce some compile-time xref	*/
 
 
 !File: debug.h
-#undef DEBUG		1	/* perform various self-tests		*/
+/*#define DEBUG		1	/* perform various self-tests		*/
 
 
 !File: use_tmp.h
-#undef PREPEND_SCOPES	1	/* collect exa, exp, ina and inp commands
+/*#define PREPEND_SCOPES	1	/* collect exa, exp, ina and inp commands
 					and if USE_TMP is defined let them
 					precede the rest of the generated
 					compact code	*/
-#undef USE_TMP		1	/* use C_insertpart, C_endpart mechanism
+/*#define USE_TMP		1	/* use C_insertpart, C_endpart mechanism
 					to generate EM-code in the order needed
 					for the code-generators. If not defined,
 					the old-style peephole optimizer is
@@ -112,17 +112,17 @@
 
 
 !File: nopp.h
-#undef NOPP		1	/* if NOT defined, use built-int preprocessor */
+/*#define NOPP		1	/* if NOT defined, use built-int preprocessor */
 
 
 !File: nobitfield.h
-#undef NOBITFIELD	1	/* if NOT defined, implement bitfields	*/
+/*#define NOBITFIELD	1	/* if NOT defined, implement bitfields	*/
 
 
 !File: spec_arith.h
 /* describes internal compiler arithmetics */
-#undef	SPECIAL_ARITHMETICS	/* something different from native long */
-#undef UNSIGNED_ARITH	unsigned arith
+/*#define	SPECIAL_ARITHMETICS	/* something different from native long */
+/*#define UNSIGNED_ARITH	unsigned arith	/* when it is supported */
 
 
 !File: static.h
@@ -130,14 +130,14 @@
 
 
 !File: nocross.h
-#undef NOCROSS		1	/* if NOT defined, cross compiler */
+/*#define NOCROSS		1	/* if NOT defined, cross compiler */
 
 
 !File: regcount.h
-#undef REGCOUNT		1	/* count occurrences for register messages */
+/*#define REGCOUNT		1	/* count occurrences for register messages */
 
 
 !File: dbsymtab.h
-#undef DBSYMTAB	1	/* ability to produce symbol table for debugger */
+/*#define DBSYMTAB	1	/* ability to produce symbol table for debugger */
 
 
diff --git a/lang/cem/lint/lpass1/Parameters b/lang/cem/lint/lpass1/Parameters
index 87ac8bf0e..9d33d7fae 100644
--- a/lang/cem/lint/lpass1/Parameters
+++ b/lang/cem/lint/lpass1/Parameters
@@ -75,23 +75,23 @@
 
 
 !File: botch_free.h
-#undef BOTCH_FREE	1	/* when defined, botch freed memory, as a check	*/
+/*#define BOTCH_FREE	1	/* when defined, botch freed memory, as a check	*/
 
 
 !File: dataflow.h
-#undef	DATAFLOW	1	/* produce some compile-time xref	*/
+/*#define	DATAFLOW	1	/* produce some compile-time xref	*/
 
 
 !File: debug.h
-#undef DEBUG		1	/* perform various self-tests		*/
+/*#define DEBUG		1	/* perform various self-tests		*/
 
 
 !File: use_tmp.h
-#undef PREPEND_SCOPES	1	/* collect exa, exp, ina and inp commands
+/*#define PREPEND_SCOPES	1	/* collect exa, exp, ina and inp commands
 					and if USE_TMP is defined let them
 					precede the rest of the generated
 					compact code	*/
-#undef USE_TMP		1	/* use C_insertpart, C_endpart mechanism
+/*#define USE_TMP		1	/* use C_insertpart, C_endpart mechanism
 					to generate EM-code in the order needed
 					for the code-generators. If not defined,
 					the old-style peephole optimizer is
@@ -112,16 +112,16 @@
 
 
 !File: nopp.h
-#undef NOPP		1	/* if NOT defined, use built-int preprocessor */
+/*#define NOPP		1	/* if NOT defined, use built-int preprocessor */
 
 
 !File: nobitfield.h
-#undef NOBITFIELD	1	/* if NOT defined, implement bitfields	*/
+/*#define NOBITFIELD	1	/* if NOT defined, implement bitfields	*/
 
 
 !File: spec_arith.h
 /* describes internal compiler arithmetics */
-#undef	SPECIAL_ARITHMETICS	/* something different from native long */
+/*#define	SPECIAL_ARITHMETICS	/* something different from native long */
 
 
 !File: static.h
@@ -129,22 +129,22 @@
 
 
 !File: nofloat.h
-#undef NOFLOAT		1	/* if NOT defined, floats are implemented */
+/*#define NOFLOAT		1	/* if NOT defined, floats are implemented */
 
 
 !File: noRoption.h
-#undef NOROPTION	1	/* if NOT defined, R option is implemented */
+/*#define NOROPTION	1	/* if NOT defined, R option is implemented */
 
 
 !File: nocross.h
-#undef NOCROSS		1	/* if NOT defined, cross compiler */
+/*#define NOCROSS		1	/* if NOT defined, cross compiler */
 
 
 !File: regcount.h
-#undef REGCOUNT		1	/* count occurrences for register messages */
+/*#define REGCOUNT		1	/* count occurrences for register messages */
 
 
 !File: dbsymtab.h
-#undef DBSYMTAB		1	/* debugger support */
+/*#define DBSYMTAB		1	/* debugger support */