diff --git a/src/basic/enum_to_string/my_enum_scanner.cc b/src/basic/enum_to_string/my_enum_scanner.cc
index 40e1577c42..375d2344c5 100644
--- a/src/basic/enum_to_string/my_enum_scanner.cc
+++ b/src/basic/enum_to_string/my_enum_scanner.cc
@@ -130,7 +130,7 @@ if ( first_call )  { init();  first_call = false; }
 
 yytext = (char *) lexeme;
 
-while ( 1 )  {
+while ( true )  {
 
    t = next_token();
 
@@ -174,7 +174,7 @@ int c, c2;
    //  skip whitespace
    //
 
-while ( 1 )  {
+while ( true )  {
 
    c = nextchar();
 
@@ -600,7 +600,7 @@ c1 = nextchar();
 c2 = nextchar();
 
 
-while ( 1 )  {
+while ( true )  {
 
    if ( (c1 == EOF) || (c2 == EOF) )  break;
 
@@ -629,7 +629,7 @@ void do_cpp_comment()
 int c;
 
 
-while ( 1 )  {
+while ( true )  {
 
    c = nextchar();
 
diff --git a/src/basic/vx_config/config.tab.cc b/src/basic/vx_config/config.tab.cc
index 6805b14a43..61513c670b 100644
--- a/src/basic/vx_config/config.tab.cc
+++ b/src/basic/vx_config/config.tab.cc
@@ -2421,7 +2421,7 @@ DictionaryEntry e;
 
 count = 0;
 
-while ( 1 )  {
+while ( true )  {
 
    v = icvs.pop();
 
diff --git a/src/basic/vx_config/config_file.cc b/src/basic/vx_config/config_file.cc
index c1b363b452..441fa3a9a8 100644
--- a/src/basic/vx_config/config_file.cc
+++ b/src/basic/vx_config/config_file.cc
@@ -622,7 +622,7 @@ void recursive_envs(string & line)
 
 {
 
-while ( 1 )  {
+while ( true )  {
 
    if ( ! replace_env(line) )  break;
 
diff --git a/src/basic/vx_config/my_config_scanner.cc b/src/basic/vx_config/my_config_scanner.cc
index f630924c98..13e41a196c 100644
--- a/src/basic/vx_config/my_config_scanner.cc
+++ b/src/basic/vx_config/my_config_scanner.cc
@@ -188,7 +188,7 @@ if ( first_call )  { init();  first_call = false; }
 
 configtext = (char *) lexeme;
 
-while ( 1 )  {
+while ( true )  {
 
    t = next_token();
 
@@ -218,7 +218,7 @@ int c, c2;
    //  skip whitespace
    //
 
-while ( 1 )  {
+while ( true )  {
 
    c = nextchar();
 
@@ -827,7 +827,7 @@ c1 = nextchar();
 c2 = nextchar();
 
 
-while ( 1 )  {
+while ( true )  {
 
    if ( (c1 == eof) || (c2 == eof) )  break;
 
@@ -858,7 +858,7 @@ int c = 0;
 
 reading_comment = true;
 
-while ( 1 )  {
+while ( true )  {
 
    if ( configin->eof() )  break;
 
@@ -1034,7 +1034,7 @@ if ( c == '$' )  {
 
    env_value = e;
 
-   while ( 1 )  {
+   while ( true )  {
 
       if ( ! replace_env(env_value) )  break;
 
diff --git a/src/basic/vx_util/command_line.cc b/src/basic/vx_util/command_line.cc
index 0f9e205ebe..de06658b07 100644
--- a/src/basic/vx_util/command_line.cc
+++ b/src/basic/vx_util/command_line.cc
@@ -1093,7 +1093,7 @@ a.clear();
 
 count = 0;
 
-while ( 1 )  {
+while ( true )  {
 
    k = pos + count;
 
diff --git a/src/libcode/vx_afm/afm.cc b/src/libcode/vx_afm/afm.cc
index 31974f00d0..28b15563d6 100644
--- a/src/libcode/vx_afm/afm.cc
+++ b/src/libcode/vx_afm/afm.cc
@@ -1903,7 +1903,7 @@ ascii_code = tok.i;
 c.ascii_code = ascii_code;
 
 
-while ( 1 )  {
+while ( true )  {
    tok = line.nexttoken();
 
    if ( tok.type == afm_token_endofline )  break;
@@ -2024,7 +2024,7 @@ c.pcc = new PCC [c.n_parts];
 
 n_pcc = 0;
 
-while ( 1 )  {
+while ( true )  {
 
    tok = line.nexttoken();
 
diff --git a/src/libcode/vx_afm/afm_line.cc b/src/libcode/vx_afm/afm_line.cc
index 4371e6f00e..fdf05c6aec 100644
--- a/src/libcode/vx_afm/afm_line.cc
+++ b/src/libcode/vx_afm/afm_line.cc
@@ -334,7 +334,7 @@ extern istream & operator>>(istream & in, AfmLine & L)
 
 L.clear();
 
-while ( 1 )  {
+while ( true )  {
 
   L.Line.read_line(in);
 
diff --git a/src/libcode/vx_bool_calc/make_program.cc b/src/libcode/vx_bool_calc/make_program.cc
index dabbb8b7ec..8f35e5824a 100644
--- a/src/libcode/vx_bool_calc/make_program.cc
+++ b/src/libcode/vx_bool_calc/make_program.cc
@@ -65,7 +65,7 @@ tiz.set(input);
 
    ////////////////
 
-while ( 1 )  {
+while ( true )  {
 
    tok = tiz.next_token();
 
diff --git a/src/libcode/vx_bool_calc/tokenizer.cc b/src/libcode/vx_bool_calc/tokenizer.cc
index eed9ada855..7a7d690819 100644
--- a/src/libcode/vx_bool_calc/tokenizer.cc
+++ b/src/libcode/vx_bool_calc/tokenizer.cc
@@ -167,7 +167,7 @@ char c, c2;
    //  skip whitespace
    //
 
-while ( 1 )  {
+while ( true )  {
 
    c = source[pos];
 
diff --git a/src/libcode/vx_color/my_color_scanner.cc b/src/libcode/vx_color/my_color_scanner.cc
index fcd4ef525f..5994787349 100644
--- a/src/libcode/vx_color/my_color_scanner.cc
+++ b/src/libcode/vx_color/my_color_scanner.cc
@@ -126,7 +126,7 @@ if ( first_call )  { init();  first_call = false; }
 
 colortext = (char *) lexeme;
 
-while ( 1 )  {
+while ( true )  {
 
    t = next_token();
 
@@ -156,7 +156,7 @@ int c, c2;
    //  skip whitespace
    //
 
-while ( 1 )  {
+while ( true )  {
 
    c = nextchar();
 
@@ -765,7 +765,7 @@ c1 = nextchar();
 c2 = nextchar();
 
 
-while ( 1 )  {
+while ( true )  {
 
    if ( (c1 == EOF) || (c2 == EOF) )  break;
 
@@ -794,7 +794,7 @@ void do_cpp_comment()
 int c;
 
 
-while ( 1 )  {
+while ( true )  {
 
    c = nextchar();
 
diff --git a/src/libcode/vx_pxm/pbm.cc b/src/libcode/vx_pxm/pbm.cc
index 9c1e39b7e8..4d4f622327 100644
--- a/src/libcode/vx_pxm/pbm.cc
+++ b/src/libcode/vx_pxm/pbm.cc
@@ -364,7 +364,7 @@ if ( (c1 != 'P') || (c2 != '4') )  {
 
 skip_whitespace(in);
 
-while ( 1 )  {
+while ( true )  {
 
    j = in.peek();
 
diff --git a/src/libcode/vx_pxm/pcm.cc b/src/libcode/vx_pxm/pcm.cc
index 1fe14b5ee9..c6c41d4878 100644
--- a/src/libcode/vx_pxm/pcm.cc
+++ b/src/libcode/vx_pxm/pcm.cc
@@ -446,7 +446,7 @@ if ( (c1 != 'P') || (c2 != '9') )  {
 
 skip_whitespace(in);
 
-while ( 1 )  {
+while ( true )  {
 
    j = in.peek();
 
diff --git a/src/libcode/vx_pxm/pgm.cc b/src/libcode/vx_pxm/pgm.cc
index 47d1c7732b..87f6170bc0 100644
--- a/src/libcode/vx_pxm/pgm.cc
+++ b/src/libcode/vx_pxm/pgm.cc
@@ -326,7 +326,7 @@ if ( (c1 != 'P') || (c2 != '5') )  {
 
 skip_whitespace(in);
 
-while ( 1 )  {
+while ( true )  {
 
    j = in.peek();
 
diff --git a/src/libcode/vx_pxm/ppm.cc b/src/libcode/vx_pxm/ppm.cc
index af49251531..9ce2c79e44 100644
--- a/src/libcode/vx_pxm/ppm.cc
+++ b/src/libcode/vx_pxm/ppm.cc
@@ -326,7 +326,7 @@ if ( (c1 != 'P') || (c2 != '6') )  {
 
 skip_whitespace(in);
 
-while ( 1 )  {
+while ( true )  {
 
    j = in.peek();
 
diff --git a/src/libcode/vx_pxm/pxm_utils.cc b/src/libcode/vx_pxm/pxm_utils.cc
index 0a1663a6fe..c238c3b94b 100644
--- a/src/libcode/vx_pxm/pxm_utils.cc
+++ b/src/libcode/vx_pxm/pxm_utils.cc
@@ -53,7 +53,7 @@ void skip_whitespace(istream & in)
 
 int c;
 
-while ( 1 )  {
+while ( true )  {
 
    c = in.peek();
 
@@ -82,7 +82,7 @@ in.get(c);   //  toss leading '#'
 
 k = 0;
 
-while ( 1 )  {
+while ( true )  {
 
    in.get(c);
 
diff --git a/src/tools/dev_utils/nceptab_to_flat.cc b/src/tools/dev_utils/nceptab_to_flat.cc
index c24585b0ae..4041cab117 100644
--- a/src/tools/dev_utils/nceptab_to_flat.cc
+++ b/src/tools/dev_utils/nceptab_to_flat.cc
@@ -212,7 +212,7 @@ if ( !found )  {
    //
 
 
-while ( 1 )  {
+while ( true )  {
 
    line.read_line(in);