diff --git a/src/ikarus.boot b/src/ikarus.boot
index 0235de3..9fa4972 100644
Binary files a/src/ikarus.boot and b/src/ikarus.boot differ
diff --git a/src/ikarus.reader.ss b/src/ikarus.reader.ss
index 4523afd..cea015b 100644
--- a/src/ikarus.reader.ss
+++ b/src/ikarus.reader.ss
@@ -76,6 +76,30 @@
               [($char= #\n c) (tokenize-string (cons #\newline ls) p)]
               [($char= #\r c) (tokenize-string (cons #\return ls) p)]
               [($char= #\t c) (tokenize-string (cons #\tab ls) p)]
+              [($char= #\x c) ;;; unicode escape \xXXX;
+               (let ([c (read-char p)])
+                 (cond
+                   [(eof-object? c) 
+                    (error 'tokenize "invalid eof inside string")]
+                   [(hex c) =>
+                    (lambda (n)
+                      (let f ([n n])
+                        (let ([c (read-char p)])
+                          (cond
+                            [(eof-object? n) 
+                             (error 'tokenize "invalid eof inside string")]
+                            [(hex c) =>
+                             (lambda (v) (f (+ (* n 16) v)))]
+                            [($char= c #\;) 
+                             (tokenize-string
+                               (cons (integer->char n) ls) p)]
+                            [else
+                             (error 'tokenize
+                               "invalid char ~a in escape sequence"
+                               c)]))))]
+                   [else 
+                    (error 'tokenize
+                      "invalid char ~a in escape sequence" c)]))]
               [else (error 'tokenize "invalid string escape \\~a" c)]))]
          [else
           (tokenize-string (cons c ls) p)]))))
diff --git a/src/unicode/extract-char-cases.ss b/src/unicode/extract-char-cases.ss
index 6762e69..7e9c7fa 100755
--- a/src/unicode/extract-char-cases.ss
+++ b/src/unicode/extract-char-cases.ss
@@ -16,6 +16,7 @@
       (let ([n (hex->num num)])
         (define (f x)
           (if (string=? x "") 0 (- (hex->num x) n)))
+        ;#(UC LC TC FC string-FC)
         (cons n (vector (f uc) (f lc) (f tc) #f 0))))))
 
 (define (remove-dups ls)
@@ -98,25 +99,12 @@
                   (convert-full-fold-fields (cdr ls)))))]
            [else (convert-full-fold-fields (cdr ls))])))]))
 
-
-#;
-(define (convert-index ls)
-  (let ([alist
-         (let f ([i 0] [ls ls])
-           (cond
-             [(null? ls) '()]
-             [else 
-              (cons (cons (car ls) (- i (car ls)))
-                    (f (add1 i) (cdr ls)))]))])
-    (map
-      (lambda (x)
-        (cons (car x) (+ (car x) (cdr x))))
-      (remove-dups alist))))
-
 (let ([ls 
+       ;;; get initial table
        (compute-foldcase
          (map data-case 
            (get-unicode-data "UNIDATA/UnicodeData.txt")))])
+  ;;; compute the string-foldcase data
   (for-each
     (lambda (x) 
       (let ([n (car x)] [chars (cdr x)])
@@ -127,6 +115,7 @@
           [else (error #f "~s is not there" n)])))
     (convert-full-fold-fields
       (get-unicode-data "UNIDATA/CaseFolding.txt")))
+  ;;; done
   (let ([ls (remove-dups ls)])
     (define (p name idx) 
       (pretty-print 
@@ -137,14 +126,6 @@
         (with-output-to-file "unicode-char-cases.ss"
           (lambda ()
             (printf ";;; DO NOT EDIT\n;;; automatically generated\n")
-            #;
-            (let ([ls (convert-index (map car ls))])
-              (pretty-print 
-                `(define char-search-index-vector 
-                   ',(list->vector (map car ls))))
-              (pretty-print 
-                `(define char-adjustment-index-vector 
-                   ',(list->vector (map cdr ls)))))
             (printf ";;; ~s entries in table\n" (vector-length v0))
             (pretty-print `(define charcase-search-vector ',v0))
             (p 'char-upcase-adjustment-vector 0)