diff --git a/include/time.h b/include/time.h
index 5e996ab99..bd8c22b8e 100644
--- a/include/time.h
+++ b/include/time.h
@@ -61,8 +61,8 @@ struct tm {
 };
 
 #if defined(__CBM__)
-#  if defined(__CBM610__)
-/* The 610 gets its clock from the AC current */
+#  if defined(__CBM510__) || defined(__CBM610__)
+/* The 510/610 gets its clock from the AC current */
 #    define CLK_TCK    	       	50 	/* POSIX */
 #    define CLOCKS_PER_SEC	50	/* ANSI */
 #  else
diff --git a/libsrc/dbg/dbg.c b/libsrc/dbg/dbg.c
index 7251207d8..9ddf9d80f 100644
--- a/libsrc/dbg/dbg.c
+++ b/libsrc/dbg/dbg.c
@@ -80,27 +80,19 @@ static char GetKeyUpdate (void);
 #endif
 
 /* Screen definitions */
-#ifdef __CBM610__
+#if defined(__CBM610__)
 #  define BIGSCREEN
 #  define MAX_X	   	80
 #  define MAX_Y	   	25
 #  define DUMP_BYTES	16
+#elif defined(__APPLE2__) || defined(__ATARI__)
+#  define MAX_X         40
+#  define MAX_Y         24
+#  define DUMP_BYTES     8
 #else
-#  ifdef __APPLE2__
-#    define MAX_X       40
-#    define MAX_Y       24
-#    define DUMP_BYTES   8
-#  else
-#    ifdef __ATARI__
-#      define MAX_X       40
-#      define MAX_Y       24
-#      define DUMP_BYTES   8
-#    else
-#      define MAX_X	40
-#      define MAX_Y	25
-#      define DUMP_BYTES	8
-#    endif
-#  endif
+#  define MAX_X 	40
+#  define MAX_Y	        25
+#  define DUMP_BYTES	 8
 #endif