diff --git a/Unicode/cp1250.cp b/Unicode/cp1250.cp
index 9c77c7bd..dee63471 100644
--- a/Unicode/cp1250.cp
+++ b/Unicode/cp1250.cp
@@ -147,14 +147,14 @@ Window$ 1250
 0x7E	0x007E	#TILDE
 0x7F	0x007F	#DELETE
 0x80	0x20AC	#EURO SIGN
-0x81	0x0000	#UNDEFINED
+0x81	      	#UNDEFINED
 0x82	0x201A	#SINGLE LOW-9 QUOTATION MARK
-0x83	0x0000	#UNDEFINED
+0x83	      	#UNDEFINED
 0x84	0x201E	#DOUBLE LOW-9 QUOTATION MARK
 0x85	0x2026	#HORIZONTAL ELLIPSIS
 0x86	0x2020	#DAGGER
 0x87	0x2021	#DOUBLE DAGGER
-0x88	0x0000	#UNDEFINED
+0x88	      	#UNDEFINED
 0x89	0x2030	#PER MILLE SIGN
 0x8A	0x0160	#LATIN CAPITAL LETTER S WITH CARON
 0x8B	0x2039	#SINGLE LEFT-POINTING ANGLE QUOTATION MARK
@@ -162,7 +162,7 @@ Window$ 1250
 0x8D	0x0164	#LATIN CAPITAL LETTER T WITH CARON
 0x8E	0x017D	#LATIN CAPITAL LETTER Z WITH CARON
 0x8F	0x0179	#LATIN CAPITAL LETTER Z WITH ACUTE
-0x90	0x0000	#UNDEFINED
+0x90	      	#UNDEFINED
 0x91	0x2018	#LEFT SINGLE QUOTATION MARK
 0x92	0x2019	#RIGHT SINGLE QUOTATION MARK
 0x93	0x201C	#LEFT DOUBLE QUOTATION MARK
@@ -170,7 +170,7 @@ Window$ 1250
 0x95	0x2022	#BULLET
 0x96	0x2013	#EN DASH
 0x97	0x2014	#EM DASH
-0x98	0x0000	#UNDEFINED
+0x98	      	#UNDEFINED
 0x99	0x2122	#TRADE MARK SIGN
 0x9A	0x0161	#LATIN SMALL LETTER S WITH CARON
 0x9B	0x203A	#SINGLE RIGHT-POINTING ANGLE QUOTATION MARK
diff --git a/Unicode/cp1257.cp b/Unicode/cp1257.cp
index 39a5e162..266f221e 100644
--- a/Unicode/cp1257.cp
+++ b/Unicode/cp1257.cp
@@ -23,22 +23,22 @@ Window$ 1257
 0x20-0x7e       idem
 #
 0x80	0x20AC	#EURO SIGN
-0x81	0x0000	#UNDEFINED
+0x81	      	#UNDEFINED
 0x82	0x201A	#SINGLE LOW-9 QUOTATION MARK
-0x83	0x0000	#UNDEFINED
+0x83	      	#UNDEFINED
 0x84	0x201E	#DOUBLE LOW-9 QUOTATION MARK
 0x85	0x2026	#HORIZONTAL ELLIPSIS
 0x86	0x2020	#DAGGER
 0x87	0x2021	#DOUBLE DAGGER
-0x88	0x0000	#UNDEFINED
+0x88	      	#UNDEFINED
 0x89	0x2030	#PER MILLE SIGN
-0x8A	0x0000	#UNDEFINED
+0x8A	      	#UNDEFINED
 0x8B	0x2039	#SINGLE LEFT-POINTING ANGLE QUOTATION MARK
-0x8C	0x0000	#UNDEFINED
+0x8C	      	#UNDEFINED
 0x8D	0x00A8	#DIAERESIS
 0x8E	0x02C7	#CARON
 0x8F	0x00B8	#CEDILLA
-0x90	0x0000	#UNDEFINED
+0x90	      	#UNDEFINED
 0x91	0x2018	#LEFT SINGLE QUOTATION MARK
 0x92	0x2019	#RIGHT SINGLE QUOTATION MARK
 0x93	0x201C	#LEFT DOUBLE QUOTATION MARK
@@ -46,20 +46,20 @@ Window$ 1257
 0x95	0x2022	#BULLET
 0x96	0x2013	#EN DASH
 0x97	0x2014	#EM DASH
-0x98	0x0000	#UNDEFINED
+0x98	      	#UNDEFINED
 0x99	0x2122	#TRADE MARK SIGN
-0x9A	0x0000	#UNDEFINED
+0x9A	      	#UNDEFINED
 0x9B	0x203A	#SINGLE RIGHT-POINTING ANGLE QUOTATION MARK
-0x9C	0x0000	#UNDEFINED
+0x9C	      	#UNDEFINED
 0x9D	0x00AF	#MACRON
 0x9E	0x02DB	#OGONEK
-0x9F	0x0000	#UNDEFINED
+0x9F	      	#UNDEFINED
 0xA0	0x00A0	#NO-BREAK SPACE
-0xA1	0x0000	#UNDEFINED
+0xA1	      	#UNDEFINED
 0xA2	0x00A2	#CENT SIGN
 0xA3	0x00A3	#POUND SIGN
 0xA4	0x00A4	#CURRENCY SIGN
-0xA5	0x0000	#UNDEFINED
+0xA5	      	#UNDEFINED
 0xA6	0x00A6	#BROKEN BAR
 0xA7	0x00A7	#SECTION SIGN
 0xA8	0x00D8	#LATIN CAPITAL LETTER O WITH STROKE
diff --git a/Unicode/gen-cp b/Unicode/gen-cp
index b1e289b2..83f8090d 100755
--- a/Unicode/gen-cp
+++ b/Unicode/gen-cp
@@ -23,17 +23,29 @@ for i in $codepages; do
 	echo "/*** $i ***/"
 	echo
 
-	sed '1,2d
+	sed '	# Delete the name and aliases lines.
+		1,2d
+		# Delete comment-only and blank lines.
 		/^[	 ]*\(#.*\)\{,1\}$/d
+		# Copy to the hold space.
 		h
+		# Delete everything except the comment.
 		s/^[^#]*//
+		# If there is a comment, change it to use /* */ delimiters.
 		s!#[	 ]*\(.*\)!/* \1 */!
+		# Exchange spaces; now hold space = comment and pattern space = all.
 		x
+		# Delete the comment. 
 		s/#.*//
+		# Canonicalize case so the strings can be used as lookup keys.
 		y/Xabcdef/xABCDEF/
+		# Delete mappings of bytes 0x00...0x7F.  ELinks assumes those match ASCII. 
 		/^0x[01234567]/d
-		/[^0x0123456789ABCDEF	 ]/d
+		# Delete lines that do not map the byte to exactly one character.
+		/^[ 	]*0x[0123456789ABCDEF]\{2\}[ 	]\{1,\}0x[0123456789ABCDEF]\{1,\}[ 	]*$/!d
+		# Append a newline and the comment from the hold space.
 		G
+		# Delete the newline added by the previous command.
 		s/\n//' "$i.cp" | {
 		for left in 8 9 A B C D E F; do
 			for right in 0 1 2 3 4 5 6 7 8 9 A B C D E F; do
diff --git a/src/intl/codepage.inc b/src/intl/codepage.inc
index afe53df4..026d6042 100644
--- a/src/intl/codepage.inc
+++ b/src/intl/codepage.inc
@@ -2134,14 +2134,14 @@ unsigned char *const aliases_8859_16 [] = {
 
 const uint16_t highhalf_cp1250 [] = {
 	/* 0x80 */ 0x20AC, /* EURO SIGN */
-	/* 0x81 */ 0x0000, /* UNDEFINED */
+	/* 0x81 */ 0xFFFF,
 	/* 0x82 */ 0x201A, /* SINGLE LOW-9 QUOTATION MARK */
-	/* 0x83 */ 0x0000, /* UNDEFINED */
+	/* 0x83 */ 0xFFFF,
 	/* 0x84 */ 0x201E, /* DOUBLE LOW-9 QUOTATION MARK */
 	/* 0x85 */ 0x2026, /* HORIZONTAL ELLIPSIS */
 	/* 0x86 */ 0x2020, /* DAGGER */
 	/* 0x87 */ 0x2021, /* DOUBLE DAGGER */
-	/* 0x88 */ 0x0000, /* UNDEFINED */
+	/* 0x88 */ 0xFFFF,
 	/* 0x89 */ 0x2030, /* PER MILLE SIGN */
 	/* 0x8A */ 0x0160, /* LATIN CAPITAL LETTER S WITH CARON */
 	/* 0x8B */ 0x2039, /* SINGLE LEFT-POINTING ANGLE QUOTATION MARK */
@@ -2149,7 +2149,7 @@ const uint16_t highhalf_cp1250 [] = {
 	/* 0x8D */ 0x0164, /* LATIN CAPITAL LETTER T WITH CARON */
 	/* 0x8E */ 0x017D, /* LATIN CAPITAL LETTER Z WITH CARON */
 	/* 0x8F */ 0x0179, /* LATIN CAPITAL LETTER Z WITH ACUTE */
-	/* 0x90 */ 0x0000, /* UNDEFINED */
+	/* 0x90 */ 0xFFFF,
 	/* 0x91 */ 0x2018, /* LEFT SINGLE QUOTATION MARK */
 	/* 0x92 */ 0x2019, /* RIGHT SINGLE QUOTATION MARK */
 	/* 0x93 */ 0x201C, /* LEFT DOUBLE QUOTATION MARK */
@@ -2157,7 +2157,7 @@ const uint16_t highhalf_cp1250 [] = {
 	/* 0x95 */ 0x2022, /* BULLET */
 	/* 0x96 */ 0x2013, /* EN DASH */
 	/* 0x97 */ 0x2014, /* EM DASH */
-	/* 0x98 */ 0x0000, /* UNDEFINED */
+	/* 0x98 */ 0xFFFF,
 	/* 0x99 */ 0x2122, /* TRADE MARK SIGN */
 	/* 0x9A */ 0x0161, /* LATIN SMALL LETTER S WITH CARON */
 	/* 0x9B */ 0x203A, /* SINGLE RIGHT-POINTING ANGLE QUOTATION MARK */
@@ -2710,22 +2710,22 @@ unsigned char *const aliases_cp1256 [] = {
 
 const uint16_t highhalf_cp1257 [] = {
 	/* 0x80 */ 0x20AC, /* EURO SIGN */
-	/* 0x81 */ 0x0000, /* UNDEFINED */
+	/* 0x81 */ 0xFFFF,
 	/* 0x82 */ 0x201A, /* SINGLE LOW-9 QUOTATION MARK */
-	/* 0x83 */ 0x0000, /* UNDEFINED */
+	/* 0x83 */ 0xFFFF,
 	/* 0x84 */ 0x201E, /* DOUBLE LOW-9 QUOTATION MARK */
 	/* 0x85 */ 0x2026, /* HORIZONTAL ELLIPSIS */
 	/* 0x86 */ 0x2020, /* DAGGER */
 	/* 0x87 */ 0x2021, /* DOUBLE DAGGER */
-	/* 0x88 */ 0x0000, /* UNDEFINED */
+	/* 0x88 */ 0xFFFF,
 	/* 0x89 */ 0x2030, /* PER MILLE SIGN */
-	/* 0x8A */ 0x0000, /* UNDEFINED */
+	/* 0x8A */ 0xFFFF,
 	/* 0x8B */ 0x2039, /* SINGLE LEFT-POINTING ANGLE QUOTATION MARK */
-	/* 0x8C */ 0x0000, /* UNDEFINED */
+	/* 0x8C */ 0xFFFF,
 	/* 0x8D */ 0x00A8, /* DIAERESIS */
 	/* 0x8E */ 0x02C7, /* CARON */
 	/* 0x8F */ 0x00B8, /* CEDILLA */
-	/* 0x90 */ 0x0000, /* UNDEFINED */
+	/* 0x90 */ 0xFFFF,
 	/* 0x91 */ 0x2018, /* LEFT SINGLE QUOTATION MARK */
 	/* 0x92 */ 0x2019, /* RIGHT SINGLE QUOTATION MARK */
 	/* 0x93 */ 0x201C, /* LEFT DOUBLE QUOTATION MARK */
@@ -2733,20 +2733,20 @@ const uint16_t highhalf_cp1257 [] = {
 	/* 0x95 */ 0x2022, /* BULLET */
 	/* 0x96 */ 0x2013, /* EN DASH */
 	/* 0x97 */ 0x2014, /* EM DASH */
-	/* 0x98 */ 0x0000, /* UNDEFINED */
+	/* 0x98 */ 0xFFFF,
 	/* 0x99 */ 0x2122, /* TRADE MARK SIGN */
-	/* 0x9A */ 0x0000, /* UNDEFINED */
+	/* 0x9A */ 0xFFFF,
 	/* 0x9B */ 0x203A, /* SINGLE RIGHT-POINTING ANGLE QUOTATION MARK */
-	/* 0x9C */ 0x0000, /* UNDEFINED */
+	/* 0x9C */ 0xFFFF,
 	/* 0x9D */ 0x00AF, /* MACRON */
 	/* 0x9E */ 0x02DB, /* OGONEK */
-	/* 0x9F */ 0x0000, /* UNDEFINED */
+	/* 0x9F */ 0xFFFF,
 	/* 0xA0 */ 0x00A0, /* NO-BREAK SPACE */
-	/* 0xA1 */ 0x0000, /* UNDEFINED */
+	/* 0xA1 */ 0xFFFF,
 	/* 0xA2 */ 0x00A2, /* CENT SIGN */
 	/* 0xA3 */ 0x00A3, /* POUND SIGN */
 	/* 0xA4 */ 0x00A4, /* CURRENCY SIGN */
-	/* 0xA5 */ 0x0000, /* UNDEFINED */
+	/* 0xA5 */ 0xFFFF,
 	/* 0xA6 */ 0x00A6, /* BROKEN BAR */
 	/* 0xA7 */ 0x00A7, /* SECTION SIGN */
 	/* 0xA8 */ 0x00D8, /* LATIN CAPITAL LETTER O WITH STROKE */