diff --git a/scheme/ikarus.io.ss b/scheme/ikarus.io.ss
index f613068..f29d4f3 100644
--- a/scheme/ikarus.io.ss
+++ b/scheme/ikarus.io.ss
@@ -25,6 +25,8 @@
     open-string-input-port
     make-custom-binary-input-port 
     make-custom-binary-output-port 
+    make-custom-textual-input-port 
+    make-custom-textual-output-port 
     transcoded-port port-transcoder
     close-port close-input-port close-output-port
     port-eof?
@@ -69,6 +71,8 @@
       open-string-input-port
       make-custom-binary-input-port
       make-custom-binary-output-port 
+      make-custom-textual-input-port 
+      make-custom-textual-output-port 
       transcoded-port port-transcoder
       close-port close-input-port close-output-port
       port-eof?
@@ -188,6 +192,12 @@
       ($make-port 0 0 bv 0 #f #f attrs id read! write! get-position
                   set-position! close)))
 
+  (define ($make-custom-textual-port attrs id 
+            read! write! get-position set-position! close buffer-size)
+    (let ([bv (make-string buffer-size)])
+      ($make-port 0 0 bv 0 #f #f attrs id read! write! get-position
+                  set-position! close)))
+
   (define (make-custom-binary-input-port id 
             read! get-position set-position! close)
     ;;; FIXME: get-position and set-position! are ignored for now
@@ -218,6 +228,38 @@
       id #f write! get-position
       set-position! close 256))
 
+  (define (make-custom-textual-input-port id 
+            read! get-position set-position! close)
+    ;;; FIXME: get-position and set-position! are ignored for now
+    (define who 'make-custom-textual-input-port)
+    (unless (string? id)
+      (error who "id is not a string" id))
+    (unless (procedure? read!)
+      (error who "read! is not a procedure" read!))
+    (unless (or (procedure? close) (not close))
+      (error who "close should be either a procedure or #f" close))
+    ($make-custom-textual-port 
+      (fxior fast-get-tag fast-get-char-tag)
+      id read! #f get-position
+      set-position! close 256))
+
+  (define (make-custom-textual-output-port id 
+            write! get-position set-position! close)
+    ;;; FIXME: get-position and set-position! are ignored for now
+    (define who 'make-custom-textual-output-port)
+    (unless (string? id)
+      (error who "id is not a string" id))
+    (unless (procedure? write!)
+      (error who "read! is not a procedure" write!))
+    (unless (or (procedure? close) (not close))
+      (error who "close should be either a procedure or #f" close))
+    ($make-custom-textual-port 
+      (fxior fast-put-tag fast-put-char-tag)
+      id #f write! get-position
+      set-position! close 256))
+
+
+
   (define (input-transcoder-attrs x)
     (cond
       [(not x) ;;; binary input port
diff --git a/scheme/last-revision b/scheme/last-revision
index 4c11389..efffd3b 100644
--- a/scheme/last-revision
+++ b/scheme/last-revision
@@ -1 +1 @@
-1213
+1214
diff --git a/scheme/makefile.ss b/scheme/makefile.ss
index 7cd717b..dd57baf 100755
--- a/scheme/makefile.ss
+++ b/scheme/makefile.ss
@@ -1097,11 +1097,11 @@
     [lookahead-u8                                i r ip]
     [make-bytevector                             i r bv]
     [make-custom-binary-input-port               i r ip]
-    [make-custom-binary-input/output-port        r ip]
     [make-custom-binary-output-port              i r ip]
-    [make-custom-textual-input-port              r ip]
+    [make-custom-textual-input-port              i r ip]
+    [make-custom-textual-output-port             i r ip]
+    [make-custom-binary-input/output-port        r ip]
     [make-custom-textual-input/output-port       r ip]
-    [make-custom-textual-output-port             r ip]
     [make-i/o-decoding-error                     i r ip]
     [make-i/o-encoding-error                     i r ip]
     [make-i/o-error                              i r ip is fi]
diff --git a/scheme/tests/io.ss b/scheme/tests/io.ss
index 67e7291..85c570c 100755
--- a/scheme/tests/io.ss
+++ b/scheme/tests/io.ss
@@ -477,12 +477,12 @@
               #f)])
     (let f ([i 0])
       (unless (fx= i 10000)
-        (put-u8 p (mod i 256))
+        (put-u8 p (mod i 37))
         (f (+ i 1))))
     (flush-output-port p)
     (let f ([i 0] [ls (reverse ls)])
       (unless (null? ls) 
-        (assert (fx= (mod i 256) (car ls)))
+        (assert (fx= (mod i 37) (car ls)))
         (f (fx+ i 1) (cdr ls))))))
 
 
diff --git a/scheme/todo-r6rs.ss b/scheme/todo-r6rs.ss
index 9136a67..dc346a3 100755
--- a/scheme/todo-r6rs.ss
+++ b/scheme/todo-r6rs.ss
@@ -606,11 +606,11 @@
     [lookahead-u8                               C ip]
     [make-bytevector                            C bv]
     [make-custom-binary-input-port              C ip]
-    [make-custom-binary-input/output-port       S ip]
     [make-custom-binary-output-port             C ip]
-    [make-custom-textual-input-port             S ip]
+    [make-custom-textual-input-port             C ip]
+    [make-custom-textual-output-port            C ip]
+    [make-custom-binary-input/output-port       S ip]
     [make-custom-textual-input/output-port      S ip]
-    [make-custom-textual-output-port            S ip]
     [make-i/o-decoding-error                    C ip]
     [make-i/o-encoding-error                    C ip]
     [make-i/o-error                             C ip is fi]