diff --git a/femto.primitives.c b/femto.primitives.c
index 84f5143..e13d200 100644
--- a/femto.primitives.c
+++ b/femto.primitives.c
@@ -62,6 +62,7 @@ extern int get_mode_current_buffer(char *);
 extern int save_buffer_byname(char *);
 extern int count_buffers(void);
 extern void display_prompt_and_response(char *, char *);
+extern int replace_string_function(char *, char *, int);
 extern void msg(char *,...);
 extern void clear_message_line(void);
 extern void log_message(char *);
@@ -153,6 +154,12 @@ Object *e_show_prompt(Interpreter *interp, Object **args, Object **env)
     return t;
 }
 
+Object *e_replace_string_function(Interpreter *interp, Object **args, Object **env)
+{
+    int result = replace_string_function(FLISP_ARG_ONE->string, FLISP_ARG_TWO->string, FLISP_ARG_THREE->integer);
+    return (result == 1 ? t : nil);
+}
+
 Object *e_prompt(Interpreter *interp, Object **args, Object **env)
 {
     char response[81];
diff --git a/femto.register.c b/femto.register.c
index f05f861..99bcbcb 100644
--- a/femto.register.c
+++ b/femto.register.c
@@ -21,6 +21,7 @@ available to be called as lisp functions
     {"get-point-max",             0, 0, 0,         e_get_point_max},
     {"set-key",                   2, 2, TYPE_STRING, e_set_key},
     {"prompt",                    2, 2, TYPE_STRING, e_prompt},
+    {"replace-string",            3, 3, TYPE_STRING, e_replace_string_function},
     {"show-prompt",               2, 2, TYPE_STRING, e_show_prompt},
     {"eval-block",                0, 0, 0,         e_eval_block},
     {"get-buffer-name",           0, 0, 0,         e_get_buffer_name},
diff --git a/header.h b/header.h
index 0ab868e..485144a 100644
--- a/header.h
+++ b/header.h
@@ -441,6 +441,7 @@ extern void execute_key(void);
 extern void make_key(char *, char *);
 extern void setup_keys(void);
 
+
 /* functions in main.c */
 extern int main(int argc, char **);
 extern void debug(char *format, ...);
@@ -453,6 +454,8 @@ extern void gui(void);              /* The GUI loop used in interactive mode */
 /* functions in replace.c */
 extern void query_replace(void);
 extern void replace_string(buffer_t *, char *, char *, int, int);
+extern int replace_string_function(char *, char *, int);
+
 
 /* functions in search.c */
 extern point_t search_backwards(char *);
diff --git a/lisp/dired.lsp b/lisp/dired.lsp
index 187ba19..93fe198 100644
--- a/lisp/dired.lsp
+++ b/lisp/dired.lsp
@@ -15,15 +15,20 @@
 ;;
 ;;
 ;;
-;; (load "path/dired.lsp")   ;; to load
+;;
+;; (load "./lisp/dired.lsp") ;; when testing locally or developing
+;;
 ;; (dired)                   ;; to call
 ;;
 ;;
 (require 'femto)
 
 
+;;
+;;  these contain the state of dired and need to be global
 ;;
 (setq dired-dir "")
+(setq dired-fspec "")
 (setq dired-ls-cmd "ls -la ")
 (setq dired-buffer "*dired*")
 (setq de-obuf "*scratch*")
@@ -36,7 +41,7 @@
 (setq de-is-dir nil)
 (setq de-is-link nil)
 (setq de-ops 0)
-(setq de-max-ops 300)
+(setq de-max-ops 3000)
 (setq de-debug nil)
 
 (defun dired ()
@@ -45,7 +50,7 @@
   (delete-other-windows)
   (setq de-obuf (get-buffer-name))
   (kill-buffer dired-buffer)
-  (shell-command (concat dired-ls-cmd dired-dir))
+  (shell-command (concat dired-ls-cmd dired-dir "/" dired-fspec))
   (rename-buffer dired-buffer)
   (beginning-of-buffer)
   (set-mark)
@@ -57,7 +62,6 @@
   (de-get-info)
   (de-loop))
 
-
 (defun de-init()
   (setq de-start-line 1)
   (setq de-last-line 1)
@@ -98,7 +102,7 @@
   (setq de-ops (+ de-ops 1))
   (cond
     ((< de-ops de-max-ops)
-     (message "dired menu: f,x")
+     (message "dired menu: s,f,x")
      (update-display)
      (setq de-key (get-key))
      (cond
@@ -124,12 +128,21 @@
        (t (de-open-file)))
      (kill-buffer dired-buffer)
      (setq de-ops (+ de-max-ops 1)))
+    ((memq k '("s"))
+     (de-set-fspec)
+     (dired))
     (t (log-debug (concat "command key=" k "\n")))))
 
 
 (defun de-open-file()
   (find-file (concat dired-dir "/" de-name)))
 
+;;
+;; set the filter specification for the files (eg *.c)
+;;
+(defun de-set-fspec() 
+  (setq dired-fspec (prompt "Enter file filter specification:  " dired-fspec)))
+
 (defun de-open-dir()
   (dired-debug de-name)
   (cond
diff --git a/misc/questions.txt b/misc/questions.txt
new file mode 100644
index 0000000..8d7cf4c
--- /dev/null
+++ b/misc/questions.txt
@@ -0,0 +1,15 @@
+
+what are .sht files ?
+
+
+
+/usr/share/femto/femto.rc ->  startup
+
+startup 
+  loads the extension files
+  set the config keys
+  load the local config from ~/HOME/.config/femto.rc
+  
+core.lsp - not in the share directory
+-- assume loaded by the standalone lisp programme
+
diff --git a/replace.c b/replace.c
index 67f90bb..31e835a 100644
--- a/replace.c
+++ b/replace.c
@@ -84,6 +84,68 @@ void query_replace(void)
     msg("%d substitutions", numsub);
 }
 
+
+/*
+
+replace_string_function()
+
+Non interactive version for calling through lisp
+Will replace search string from current point in buffer
+to end of buffer
+
+rcount = number of replacements allowed, 0 means do all
+
+*/
+
+int replace_string_function(char *s, char *r, int rcount)
+{
+    point_t o_point = curbp->b_point;
+    point_t l_point = -1;
+    point_t found;
+    int slen, rlen;   /* length of search and replace strings */
+    int numsub = 0;   /* number of substitutions */
+
+    strcpy(searchtext, s);
+    strcpy(replace, r);
+
+    slen = strlen(searchtext);
+    rlen = strlen(replace);
+
+    /* 
+    We should do some searious sanity checks here
+    to avoid potentiall infinite loops etc
+    */
+
+    /* scan through the file, from point */
+    numsub = 0;
+    while(TRUE) {
+
+        // have we done the allowed number of replacements ?
+        // rcount of 0 means do all
+        if (rcount > 0 && numsub >= rcount)
+            break;
+
+        found = search_forward(searchtext);
+
+        /* if not found set the point to the last point of replacement, or where we started */
+        if (found == -1) {
+            curbp->b_point = (l_point == -1 ? o_point : l_point);
+            break;
+        }
+
+        curbp->b_point = found;
+        /* search_forward places point at end of search, move to start of search */
+        curbp->b_point -= slen;
+
+        l_point = curbp->b_point; /* save last point */
+        replace_string(curbp, searchtext, replace, slen, rlen);
+        numsub++;
+    }
+
+    return numsub;
+}
+
+
 void replace_string(buffer_t *bp, char *s, char *r, int slen, int rlen)
 {
     /*