diff --git a/C/iopreds.c b/C/iopreds.c
index 9a04d709b..672036cfa 100644
--- a/C/iopreds.c
+++ b/C/iopreds.c
@@ -89,7 +89,6 @@ static char SccsId[] = "%W% %G%";
 
 STATIC_PROTO (Int PlIOError, (yap_error_number, Term, char *));
 STATIC_PROTO (int FilePutc, (int, int));
-STATIC_PROTO (int MemPutc, (int, int));
 STATIC_PROTO (int console_post_process_read_char, (int, StreamDesc *));
 STATIC_PROTO (int console_post_process_eof, (StreamDesc *));
 STATIC_PROTO (int post_process_read_char, (int, StreamDesc *));
@@ -100,14 +99,12 @@ STATIC_PROTO (int ConsoleSocketPutc, (int, int));
 #endif
 STATIC_PROTO (int PipePutc, (int, int));
 STATIC_PROTO (int ConsolePipePutc, (int, int));
-STATIC_PROTO (int NullPutc, (int, int));
 STATIC_PROTO (int ConsolePutc, (int, int));
 STATIC_PROTO (Int p_setprompt, (void));
 STATIC_PROTO (Int p_prompt, (void));
 STATIC_PROTO (int PlGetc, (int));
 STATIC_PROTO (int DefaultGets, (int,UInt,char*));
 STATIC_PROTO (int PlGets, (int,UInt,char*));
-STATIC_PROTO (int MemGetc, (int));
 STATIC_PROTO (int ISOWGetc, (int));
 STATIC_PROTO (int ConsoleGetc, (int));
 STATIC_PROTO (int PipeGetc, (int));
@@ -265,7 +262,6 @@ yap_fflush(int sno)
   if ( (Stream[sno].status & Output_Stream_f) &&
        ! (Stream[sno].status & 
          (Null_Stream_f|
-	  InMemory_Stream_f|
 	  Socket_Stream_f|
 	  Pipe_Stream_f|
 	  Free_Stream_f)) ) {
@@ -280,10 +276,6 @@ yap_fflush(int sno)
 static void
 unix_upd_stream_info (StreamDesc * s)
 {
-  if (s->status & InMemory_Stream_f) {
-    s->status |= Seekable_Stream_f;
-    return;
-  }
 #if USE_SOCKET
   if (Yap_sockets_io &&
       s->u.file.file == NULL)
@@ -411,10 +403,6 @@ InitFileIO(StreamDesc *s)
     s->stream_putc = ConsolePipePutc;
     s->stream_wputc = put_wchar;
     s->stream_getc = ConsolePipeGetc;
-  } else if (s->status & InMemory_Stream_f) {
-    s->stream_putc = MemPutc;
-    s->stream_wputc = put_wchar;
-    s->stream_getc = MemGetc;    
   } else {
    /* check if our console is promptable: may be tty or pipe */
     if (s->status & (Promptable_Stream_f)) {
@@ -717,6 +705,12 @@ Yap_DebugPlWrite(Term t)
   Yap_plwrite(t, Yap_DebugPutc, 0, 1200);
 }
 
+void
+Yap_PlWriteToStream(Term t, int sno, int flags)
+{
+  Yap_plwrite(t, Stream[sno].stream_wputc, flags, 1200);
+}
+
 void 
 Yap_DebugErrorPutc(int c)
 {
@@ -747,67 +741,6 @@ FilePutc(int sno, int ch)
   return ((int) ch);
 }
 
-/* static */
-static int
-MemPutc(int sno, int ch)
-{
-  StreamDesc *s = &Stream[sno];
-#if MAC || _MSC_VER
-  if (ch == 10)
-    {
-      ch = '\n';
-    }
-#endif
-  s->u.mem_string.buf[s->u.mem_string.pos++] = ch;
-  if (s->u.mem_string.pos >= s->u.mem_string.max_size -256) {
-    extern int Yap_page_size;
-    int old_src = s->u.mem_string.src, new_src;
-
-    /* oops, we have reached an overflow */
-    Int new_max_size = s->u.mem_string.max_size + Yap_page_size;
-    char *newbuf;
-
-    if ((newbuf = Yap_AllocAtomSpace(new_max_size*sizeof(char))) != NULL) {
-      new_src = MEM_BUF_CODE;
-#if !USE_SYSTEM_MALLOC
-    } else if ((newbuf = (ADDR)malloc(new_max_size*sizeof(char))) != NULL)  {
-      new_src = MEM_BUF_MALLOC;
-#endif
-    } else {
-      if (Stream[sno].u.mem_string.error_handler) {
-	Yap_Error_Size = new_max_size*sizeof(char);
-	save_machine_regs();
-	longjmp(*(jmp_buf *)Stream[sno].u.mem_string.error_handler,1);
-      } else {
-	Yap_Error(OUT_OF_HEAP_ERROR, TermNil, "YAP could not grow heap for writing to string");
-      }
-      return -1;
-    }
-#if HAVE_MEMMOVE
-    memmove((void *)newbuf, (void *)s->u.mem_string.buf, (size_t)((s->u.mem_string.pos)*sizeof(char)));
-#else
-    {
-      Int n = s->u.mem_string.pos;
-      char *to = newbuf;
-      char *from = s->u.mem_string.buf;
-      while (n-- >= 0) {
-	*to++ = *from++;
-      }
-    }
-#endif
-    if (old_src == MEM_BUF_CODE) {
-      Yap_FreeAtomSpace(s->u.mem_string.buf);
-    } else {
-      free(s->u.mem_string.buf);
-    }
-    s->u.mem_string.buf = newbuf;
-    s->u.mem_string.max_size = new_max_size;
-    s->u.mem_string.src = new_src;
-  }
-  count_output_char(ch,s);
-  return ((int) ch);
-}
-
 /* static */
 static int
 IOSWIPutc(int sno, int ch)
@@ -1002,20 +935,6 @@ PipePutc (int sno, int ch)
   return ((int) ch);
 }
 
-static int
-NullPutc (int sno, int ch)
-{
-  StreamDesc *s = &Stream[sno];
-#if MAC || _MSC_VER
-  if (ch == 10)
-    {
-      ch = '\n';
-    }
-#endif
-  count_output_char(ch,s);
-  return ((int) ch);
-}
-
 /* static */
 static int
 ConsolePutc (int sno, int ch)
@@ -1285,10 +1204,6 @@ EOFGetc(int sno)
       else 
 	s->stream_putc = PipePutc;
       s->stream_wputc = put_wchar;
-    } else if (s->status & InMemory_Stream_f) {
-      s->stream_getc = MemGetc;
-      s->stream_putc = MemPutc;
-      s->stream_wputc = put_wchar;
     } else if (s->status & Promptable_Stream_f) {
       s->stream_putc = ConsolePutc;
       s->stream_wputc = put_wchar;
@@ -1603,24 +1518,6 @@ DefaultGets (int sno, UInt size, char *buf)
   return (buf-pt)-1;
 }
 
-/* read from memory */
-static int
-MemGetc (int sno)
-{
-  register StreamDesc *s = &Stream[sno];
-  Int ch;
-  int spos;
-
-  spos = s->u.mem_string.pos;
-  if (spos == s->u.mem_string.max_size) {
-    return post_process_eof(s);
-  } else {
-    ch = s->u.mem_string.buf[spos];
-    s->u.mem_string.pos = ++spos;
-  }
-  return post_process_read_char(ch, s);
-}
-
 /* I dispise this code!!!!! */
 static int
 ISOWGetc (int sno)
@@ -1696,11 +1593,7 @@ PlUnGetc (int sno)
   if (s->stream_getc != PlUnGetc)
     return(s->stream_getc(sno));
   ch = s->och;
-  if (s->status & InMemory_Stream_f) {
-    s->stream_getc = MemGetc;
-    s->stream_putc = MemPutc;
-    s->stream_wputc = put_wchar;
-  } else if (s->status & Socket_Stream_f) {
+ if (s->status & Socket_Stream_f) {
     s->stream_getc = SocketGetc;
     s->stream_putc = SocketPutc;
     s->stream_wputc = put_wchar;
@@ -2161,8 +2054,6 @@ GetStreamFd(int sno)
 #else
     return(Stream[sno].u.pipe.fd);
 #endif
-  } else if (Stream[sno].status & InMemory_Stream_f) {
-    return(-1);
   }
   return(YP_fileno(Stream[sno].u.file.file));
 }
@@ -2508,226 +2399,6 @@ Yap_OpenStream(FILE *fd, char *name, Term file_name, int flags)
   return t;
 }
 
-static Int
-p_open_pipe_stream (void)
-{
-  Term t1, t2;
-  StreamDesc *st;
-  int sno;
-#if  _MSC_VER || defined(__MINGW32__) 
-  HANDLE ReadPipe, WritePipe;
-  SECURITY_ATTRIBUTES satt;
-
-  satt.nLength = sizeof(satt);
-  satt.lpSecurityDescriptor = NULL;
-  satt.bInheritHandle = TRUE;
-  if (!CreatePipe(&ReadPipe, &WritePipe, &satt, 0))
-    {
-      return (PlIOError (SYSTEM_ERROR,TermNil, "open_pipe_stream/2 could not create pipe"));
-    }
-#else
-  int filedes[2];
-
-  if (pipe(filedes) != 0)
-    {
-      return (PlIOError (SYSTEM_ERROR,TermNil, "open_pipe_stream/2 could not create pipe"));
-    }
-#endif
-  sno = GetFreeStreamD();
-  if (sno < 0)
-    return (PlIOError (RESOURCE_ERROR_MAX_STREAMS,TermNil, "new stream not available for open_pipe_stream/2"));
-  t1 = MkStream (sno);
-  st = &Stream[sno];
-  st->status = Input_Stream_f | Pipe_Stream_f;
-  st->linepos = 0;
-  st->charcount = 0;
-  st->linecount = 1;
-  st->stream_putc = PipePutc;
-  st->stream_wputc = put_wchar;
-  st->stream_getc = PipeGetc;
-  st->stream_gets = DefaultGets;
-  st->stream_wgetc = get_wchar;
-  if (CharConversionTable != NULL)
-    st->stream_wgetc_for_read = ISOWGetc;
-  else
-    st->stream_wgetc_for_read = st->stream_wgetc;
-#if  _MSC_VER || defined(__MINGW32__) 
-  st->u.pipe.hdl = ReadPipe;
-#else
-  st->u.pipe.fd = filedes[0];
-#endif
-  UNLOCK(st->streamlock);
-  sno = GetFreeStreamD();
-  if (sno < 0)
-    return (PlIOError (RESOURCE_ERROR_MAX_STREAMS,TermNil, "new stream not available for open_pipe_stream/2"));
-  st = &Stream[sno];
-  st->status = Output_Stream_f | Pipe_Stream_f;
-  st->linepos = 0;
-  st->charcount = 0;
-  st->linecount = 1;
-  st->stream_putc = PipePutc;
-  st->stream_wputc = put_wchar;
-  st->stream_getc = PipeGetc;
-  st->stream_gets = DefaultGets;
-  st->stream_wgetc = get_wchar;
-  if (CharConversionTable != NULL)
-    st->stream_wgetc_for_read = ISOWGetc;
-  else
-    st->stream_wgetc_for_read = st->stream_wgetc; 
-#if  _MSC_VER || defined(__MINGW32__) 
-  st->u.pipe.hdl = WritePipe;
-#else
-  st->u.pipe.fd = filedes[1];
-#endif
-  UNLOCK(st->streamlock);
-  t2 = MkStream (sno);
-  return
-    Yap_unify (ARG1, t1) &&
-    Yap_unify (ARG2, t2);
-}
-
-static int
-open_buf_read_stream(char *nbuf, Int nchars)
-{
-  int sno;
-  StreamDesc *st;
- 
-
-  sno = GetFreeStreamD();
-  if (sno < 0)
-    return (PlIOError (RESOURCE_ERROR_MAX_STREAMS,TermNil, "new stream not available for open_mem_read_stream/1"));
-  st = &Stream[sno];
-  /* currently these streams are not seekable */
-  st->status = Input_Stream_f | InMemory_Stream_f;
-  st->linepos = 0;
-  st->charcount = 0;
-  st->linecount = 1;
-  st->stream_putc = MemPutc;
-  st->stream_wputc = put_wchar;
-  st->stream_getc = MemGetc;
-  st->stream_gets = DefaultGets;
-  st->stream_wgetc = get_wchar;
-  if (CharConversionTable != NULL)
-    st->stream_wgetc_for_read = ISOWGetc;
-  else
-    st->stream_wgetc_for_read = st->stream_wgetc;
-  st->u.mem_string.pos = 0;
-  st->u.mem_string.buf = nbuf;
-  st->u.mem_string.max_size = nchars;
-  st->u.mem_string.error_handler = NULL;
-  st->u.mem_string.src = MEM_BUF_CODE;
-  UNLOCK(st->streamlock);
-  return sno;
-}
-
-static Int
-p_open_mem_read_stream (void)   /* $open_mem_read_stream(+List,-Stream) */
-{
-  Term t, ti;
-  int sno;
-  Int sl = 0, nchars = 0;
-  char *nbuf;
-
-  ti = Deref(ARG1);
-  while (ti != TermNil) {
-    if (IsVarTerm(ti)) {
-      Yap_Error(INSTANTIATION_ERROR, ti, "open_mem_read_stream");
-      return (FALSE);
-    } else if (!IsPairTerm(ti)) {
-      Yap_Error(TYPE_ERROR_LIST, ti, "open_mem_read_stream");
-      return (FALSE);
-    } else {
-      sl++;
-      ti = TailOfTerm(ti);
-    }
-  }
-  while ((nbuf = (char *)Yap_AllocAtomSpace((sl+1)*sizeof(char))) == NULL) {
-    if (!Yap_growheap(FALSE, (sl+1)*sizeof(char), NULL)) {
-      Yap_Error(OUT_OF_HEAP_ERROR, TermNil, Yap_ErrorMessage);
-      return(FALSE);
-    }
-  }
-  ti = Deref(ARG1);
-  while (ti != TermNil) {
-    Term ts = HeadOfTerm(ti);
-
-    if (IsVarTerm(ts)) {
-      Yap_Error(INSTANTIATION_ERROR, ARG1, "open_mem_read_stream");
-      return (FALSE);
-    } else if (!IsIntTerm(ts)) {
-      Yap_Error(TYPE_ERROR_INTEGER, ARG1, "open_mem_read_stream");
-      return (FALSE);
-    }
-    nbuf[nchars++] = IntOfTerm(ts);
-    ti = TailOfTerm(ti);
-  }
-  nbuf[nchars] = '\0';
-  sno = open_buf_read_stream(nbuf, nchars);
-  t = MkStream (sno);
-  return (Yap_unify (ARG2, t));
-}
-
-static int
-open_buf_write_stream(char *nbuf, UInt  sz)
-{
-  int sno;
-  StreamDesc *st;
-
-  sno = GetFreeStreamD();
-  if (sno < 0)
-    return -1;
-  st = &Stream[sno];
-  /* currently these streams are not seekable */
-  st->status = Output_Stream_f | InMemory_Stream_f;
-  st->linepos = 0;
-  st->charcount = 0;
-  st->linecount = 1;
-  st->stream_putc = MemPutc;
-  st->stream_wputc = put_wchar;
-  st->stream_getc = MemGetc;
-  st->stream_gets = DefaultGets;
-  st->stream_wgetc = get_wchar;
-  if (CharConversionTable != NULL)
-    st->stream_wgetc_for_read = ISOWGetc;
-  else
-    st->stream_wgetc_for_read = st->stream_wgetc;
-  st->u.mem_string.pos = 0;
-  st->u.mem_string.buf = nbuf;
-  st->u.mem_string.max_size = sz;
-  st->u.mem_string.src = MEM_BUF_CODE;
-  UNLOCK(st->streamlock);
-  return sno;
-}
-
-static int
-OpenBufWriteStream(void)
-{
-  char *nbuf;
-  extern int Yap_page_size;
-
-
-  while ((nbuf = (char *)Yap_AllocAtomSpace(Yap_page_size*sizeof(char))) == NULL) {
-    if (!Yap_growheap(FALSE, Yap_page_size*sizeof(char), NULL)) {
-      Yap_Error(OUT_OF_HEAP_ERROR, TermNil, Yap_ErrorMessage);
-      return -1;
-    }
-  }
-  return open_buf_write_stream(nbuf, Yap_page_size);
-}
-
-static Int
-p_open_mem_write_stream (void)   /* $open_mem_write_stream(-Stream) */
-{
-  Term t;
-  int sno;
-
-  sno = OpenBufWriteStream();
-  if (sno == -1)
-    return (PlIOError (SYSTEM_ERROR,TermNil, "new stream not available for open_mem_read_stream/1"));
-  t = MkStream (sno);
-  return (Yap_unify (ARG1, t));
-}
-
 static void
 ExtendAliasArray(void)
 {
@@ -2778,7 +2449,7 @@ SetAlias (Atom arg, int sno)
       Int alno = aliasp-FileAliases;
       aliasp->alias_stream = sno;
       if (!(Stream[sno].status &
-	    (Null_Stream_f|InMemory_Stream_f|Socket_Stream_f))) {
+	    (Null_Stream_f|Socket_Stream_f))) {
 	switch(alno) {
 	case 0:
 	  Yap_stdin = Stream[sno].u.file.file;
@@ -2948,6 +2619,12 @@ LookupSWIStream (struct io_stream *swi_s)
   return i;
 }
 
+int
+Yap_LookupSWIStream (void *swi_s)
+{
+  return LookupSWIStream (swi_s);
+}
+
 typedef struct stream_ref
 { struct io_stream *read;
   struct io_stream *write;
@@ -3096,11 +2773,7 @@ StreamName(int i)
 #endif
     if (Stream[i].status & Pipe_Stream_f)
       return(MkAtomTerm(AtomPipe));
-    if (Stream[i].status & InMemory_Stream_f)
-      return(MkAtomTerm(AtomCharsio));
-    else {
-      return(Stream[i].u.file.user_name);
-    }
+  return(Stream[i].u.file.user_name);
 }
 
 static Int
@@ -3189,13 +2862,7 @@ Yap_CloseStreams (int loud)
 		  Stream[sno].u.socket.domain);
     } 
 #endif
-    else if (Stream[sno].status & InMemory_Stream_f) {
-      if (Stream[sno].u.mem_string.src == MEM_BUF_CODE) {
-	Yap_FreeAtomSpace(Stream[sno].u.mem_string.buf);
-      } else {
-	free(Stream[sno].u.mem_string.buf);
-      }
-    } else if (Stream[sno].status & (SWI_Stream_f)) {
+    else if (Stream[sno].status & (SWI_Stream_f)) {
       SWIClose(Stream[sno].u.swi_stream.swi_ptr);
     } else if (!(Stream[sno].status & Null_Stream_f)) {
       YP_fclose (Stream[sno].u.file.file);
@@ -3216,7 +2883,7 @@ Yap_CloseStreams (int loud)
 static void
 CloseStream(int sno)
 {
-  if (!(Stream[sno].status & (Null_Stream_f|Socket_Stream_f|InMemory_Stream_f|Pipe_Stream_f|SWI_Stream_f)))
+  if (!(Stream[sno].status & (Null_Stream_f|Socket_Stream_f|Pipe_Stream_f|SWI_Stream_f)))
     YP_fclose (Stream[sno].u.file.file);
 #if USE_SOCKET
   else if (Stream[sno].status & (Socket_Stream_f)) {
@@ -3231,14 +2898,7 @@ CloseStream(int sno)
 #else
     close(Stream[sno].u.pipe.fd);
 #endif
-  }
-  else if (Stream[sno].status & (InMemory_Stream_f)) {
-    if (Stream[sno].u.mem_string.src == MEM_BUF_CODE)
-      Yap_FreeAtomSpace(Stream[sno].u.mem_string.buf);
-    else
-      free(Stream[sno].u.mem_string.buf);
-  }
-  else if (Stream[sno].status & (SWI_Stream_f)) {
+  } else if (Stream[sno].status & (SWI_Stream_f)) {
     SWIClose(Stream[sno].u.swi_stream.swi_ptr);
   }
   Stream[sno].status = Free_Stream_f;
@@ -3278,39 +2938,6 @@ p_close (void)
   return (TRUE);
 }
 
-static Int
-p_peek_mem_write_stream (void)
-{				/* '$peek_mem_write_stream'(+Stream,?S0,?S) */
-  Int sno = CheckStream (ARG1, (Output_Stream_f | InMemory_Stream_f), "close/2");
-  Int i = Stream[sno].u.mem_string.pos;
-  Term tf = ARG2;
-  CELL *HI;
-
-  if (sno < 0)
-    return (FALSE);
- restart:
-  HI = H;
-  while (i > 0) {
-    --i;
-    tf = MkPairTerm(MkIntTerm(Stream[sno].u.mem_string.buf[i]),tf);
-    if (H + 1024 >= ASP) {
-      UNLOCK(Stream[sno].streamlock);
-      H = HI;
-      if (!Yap_gcl((ASP-HI)*sizeof(CELL), 3, ENV, gc_P(P,CP))) {
-	UNLOCK(Stream[sno].streamlock);
-	Yap_Error(OUT_OF_STACK_ERROR, TermNil, Yap_ErrorMessage);
-	return(FALSE);
-      }
-      i = Stream[sno].u.mem_string.pos;
-      tf = ARG2;
-      LOCK(Stream[sno].streamlock);
-      goto restart;
-    }
-  }
-  UNLOCK(Stream[sno].streamlock);
-  return (Yap_unify(ARG3,tf));
-}
-
 static Int
 p_past_eof (void)
 {				/* at_end_of_stream */
@@ -3850,6 +3477,42 @@ p_get_read_error_handler(void)
   return (Yap_unify_constant (ARG1, t));
 }
 
+int
+Yap_readTerm(int sno, Term *tp, Term *varnames, Term *terror, Term *tpos)
+{
+  TokEntry *tokstart;
+  Term pt;
+
+  if (sno < 0) {
+    return FALSE;
+  }
+  tokstart = Yap_tokptr = Yap_toktide = Yap_tokenizer(sno, tpos);
+  if (Yap_ErrorMessage)
+    {
+      Yap_clean_tokenizer(tokstart, Yap_VarTable, Yap_AnonVarTable);
+      if (terror)
+	*terror = MkAtomTerm(Yap_LookupAtom(Yap_ErrorMessage));
+      Yap_clean_tokenizer(tokstart, Yap_VarTable, Yap_AnonVarTable);
+      return FALSE;
+    }
+  pt = Yap_Parse();
+  if (Yap_ErrorMessage) {
+    Term t0 = MkVarTerm();
+    *terror = syntax_error(tokstart, sno, &t0);
+      Yap_clean_tokenizer(tokstart, Yap_VarTable, Yap_AnonVarTable);
+      return FALSE;
+  }
+  if (varnames) {
+    *varnames = Yap_VarNames(Yap_VarTable, TermNil);
+    if (!*varnames) {
+      Yap_clean_tokenizer(tokstart, Yap_VarTable, Yap_AnonVarTable);
+      return FALSE;
+    }
+  }
+  *tp = pt;
+  return TRUE;
+}
+
 /*
   Assumes
   Flag: ARG1
@@ -3901,11 +3564,7 @@ static Int
 	had_ungetc = TRUE;
 	ungetc_oldc = Stream[inp_stream].och;
       }
-      if (Stream[inp_stream].status & InMemory_Stream_f) {
-	cpos = Stream[inp_stream].u.mem_string.pos;
-      } else {
-	cpos = Stream[inp_stream].charcount;
-      }
+      cpos = Stream[inp_stream].charcount;
     }
     /* Scans the term using stack space */
     while (TRUE) {
@@ -3921,9 +3580,7 @@ static Int
 	  Stream[inp_stream].och = ungetc_oldc;
 	}
 	if (seekable) {
-	  if (Stream[inp_stream].status & InMemory_Stream_f) {
-	    Stream[inp_stream].u.mem_string.pos = cpos;
-	  } else if (Stream[inp_stream].status) {
+	  if (Stream[inp_stream].status) {
 #if HAVE_FGETPOS
 	      fsetpos(Stream[inp_stream].u.file.file, &rpos);
 #else
@@ -3962,7 +3619,7 @@ static Int
        and floats */
     old_H = H;
     if (Stream[inp_stream].status & Eof_Stream_f) {
-      if (Yap_eot_before_eof || (Stream[inp_stream].status & InMemory_Stream_f)) {
+      if (Yap_eot_before_eof) {
 	/* next read should give out an end of file */
 	Stream[inp_stream].status |= Push_Eof_Stream_f;
       } else {
@@ -4119,8 +3776,6 @@ p_user_file_name (void)
 #endif
   if (Stream[sno].status & Pipe_Stream_f)
     tout = MkAtomTerm(AtomPipe);
-  else if (Stream[sno].status & InMemory_Stream_f)
-    tout = MkAtomTerm(AtomCharsio);
   else
     tout = Stream[sno].u.file.user_name;
   UNLOCK(Stream[sno].streamlock);
@@ -4149,13 +3804,10 @@ p_cur_line_no (void)
       if (Stream[sno].status & Pipe_Stream_f)
 	my_stream = AtomPipe;
       else
-	if (Stream[sno].status & InMemory_Stream_f)
-	  my_stream = AtomCharsio;
-	else
 	  my_stream = Stream[sno].u.file.name;
       for (i = 0; i < MaxStreams; i++)
 	{
-	  if (!(Stream[i].status & (Free_Stream_f|Socket_Stream_f|Pipe_Stream_f|InMemory_Stream_f)) &&
+	  if (!(Stream[i].status & (Free_Stream_f|Socket_Stream_f|Pipe_Stream_f)) &&
 	      Stream[i].u.file.name == my_stream)
 	    no += Stream[i].linecount - 1;
 	}
@@ -4816,9 +4468,7 @@ format(volatile Term otail, volatile Term oargs, int sno)
   Term tail;
   int (* f_putc)(int, wchar_t);
   int has_tabs;
-  jmp_buf format_botch;
   volatile void *old_handler;
-  volatile int old_pos;
   format_info finfo;
   Term fmod = CurrentModule;
 
@@ -4826,27 +4476,7 @@ format(volatile Term otail, volatile Term oargs, int sno)
   FormatInfo = &finfo;
   finfo.pad_max = finfo.pad_entries;
   finfo.format_error = FALSE;
-  if (Stream[sno].status & InMemory_Stream_f) {
-    old_handler = Stream[sno].u.mem_string.error_handler;
-    Stream[sno].u.mem_string.error_handler = (void *)&format_botch;
-    old_pos = Stream[sno].u.mem_string.pos;
-    /* set up an error handler */
-    if (setjmp(format_botch)) {
-      restore_machine_regs();
-      *H++ = oargs;
-      *H++ = otail;
-      if (!Yap_growheap(FALSE, Yap_Error_Size, NULL)) {
-	Yap_Error(OUT_OF_HEAP_ERROR,otail,"format/2");
-	return FALSE;
-      }
-      oargs = H[-2];
-      otail = H[-1];
-      Stream[sno].u.mem_string.pos = old_pos;
-      H -= 2;
-    }
-  } else {
-    old_handler = NULL;
-  }
+  old_handler = NULL;
   args = oargs;
   tail = otail;
   targ = 0;
@@ -5281,9 +4911,6 @@ format(volatile Term otail, volatile Term oargs, int sno)
 	      if (IsAtomTerm(tail)) {
 		fstr = NULL;
 	      }
-	      if (Stream[sno].status & InMemory_Stream_f) {
-		Stream[sno].u.mem_string.error_handler = old_handler;
-	      }
 	      format_clean_up(finfo.format_base, fstr, targs);
 	      Yap_JumpToEnv(ball);
 	      return FALSE;
@@ -5400,9 +5027,6 @@ format(volatile Term otail, volatile Term oargs, int sno)
 	      ta[1] = oargs;
 	      Yap_Error(Yap_Error_TYPE, Yap_MkApplTerm(Yap_MkFunctor(AtomFormat,2),2,ta), "format/2");
 	    }
-	    if (Stream[sno].status & InMemory_Stream_f) {
-	      Stream[sno].u.mem_string.error_handler = old_handler;
-	    }
 	    format_clean_up(finfo.format_base, fstr, targs);
 	    Yap_Error_TYPE = YAP_NO_ERROR;
 	    return FALSE;
@@ -5424,9 +5048,6 @@ format(volatile Term otail, volatile Term oargs, int sno)
   }
   if (tnum <= 8)
     targs = NULL;
-  if (Stream[sno].status & InMemory_Stream_f) {
-    Stream[sno].u.mem_string.error_handler = old_handler;
-  }
   format_clean_up(finfo.format_base, fstr, targs);
   return (TRUE);
 }
@@ -5451,17 +5072,8 @@ format2(UInt  stream_flag)
     Yap_Error(INSTANTIATION_ERROR,tin,"format/3");
     return FALSE;
   }
-  if (IsApplTerm(tin) && FunctorOfTerm(tin) == FunctorAtom) {
-    Yap_c_output_stream = OpenBufWriteStream();
-    mem_stream = TRUE;
-  } else if (IsApplTerm(tin) && FunctorOfTerm(tin) == FunctorCodes) {
-    Yap_c_output_stream = OpenBufWriteStream();
-    codes_stream = TRUE;
-    mem_stream = TRUE;
-  } else {
-    /* needs to change Yap_c_output_stream for write */
-    Yap_c_output_stream = CheckStream (ARG1, Output_Stream_f|stream_flag, "format/3");
-  }
+  /* needs to change Yap_c_output_stream for write */
+  Yap_c_output_stream = CheckStream (ARG1, Output_Stream_f|stream_flag, "format/3");
   UNLOCK(Stream[Yap_c_output_stream].streamlock);
   if (Yap_c_output_stream == -1) {
     Yap_c_output_stream = old_c_stream;  
@@ -5931,9 +5543,6 @@ Yap_StreamToFileNo(Term t)
     UNLOCK(Stream[sno].streamlock);
     return(Stream[sno].u.socket.fd);
 #endif
-  } else if (Stream[sno].status & (Null_Stream_f|InMemory_Stream_f)) {
-    UNLOCK(Stream[sno].streamlock);
-    return(-1);
   } else {
     UNLOCK(Stream[sno].streamlock);
     return(YP_fileno(Stream[sno].u.file.file));
@@ -6087,74 +5696,6 @@ p_encoding (void)
   return TRUE;
 }
 
-Term
-Yap_StringToTerm(char *s,Term *tp)
-{
-  int sno = open_buf_read_stream(s, strlen(s)+1);
-  Term t;
-  TokEntry *tokstart;
-  tr_fr_ptr TR_before_parse;
-  Term tpos = TermNil;
-
-  if (sno < 0)
-    return FALSE;
-  UNLOCK(Stream[sno].streamlock);
-  TR_before_parse = TR;
-  tokstart = Yap_tokptr = Yap_toktide = Yap_tokenizer(sno, &tpos);
-  if (tokstart == NIL && tokstart->Tok == Ord (eot_tok)) {
-    if (tp) {
-      *tp = MkAtomTerm(AtomEOFBeforeEOT);
-    }
-    Yap_clean_tokenizer(tokstart, Yap_VarTable, Yap_AnonVarTable);
-    /* cannot actually use CloseStream, because we didn't allocate the buffer */  
-    Stream[sno].status = Free_Stream_f;
-    return FALSE;
-  } else if (Yap_ErrorMessage) {
-    if (tp) {
-      *tp = MkAtomTerm(Yap_LookupAtom(Yap_ErrorMessage));
-    }
-    Yap_clean_tokenizer(tokstart, Yap_VarTable, Yap_AnonVarTable);
-    /* cannot actually use CloseStream, because we didn't allocate the buffer */  
-    Stream[sno].status = Free_Stream_f;
-    return FALSE;
-  }
-  t = Yap_Parse();
-  TR = TR_before_parse;
-  if (!t && !Yap_ErrorMessage) {
-    if (tp) {
-      t = MkVarTerm();
-      *tp = syntax_error(tokstart, sno, &t);
-    }
-    Yap_clean_tokenizer(tokstart, Yap_VarTable, Yap_AnonVarTable);
-    /* cannot actually use CloseStream, because we didn't allocate the buffer */  
-    Stream[sno].status = Free_Stream_f;
-    return FALSE;
-  }
-  Yap_clean_tokenizer(tokstart, Yap_VarTable, Yap_AnonVarTable);
-  /* cannot actually use CloseStream, because we didn't allocate the buffer */  
-  Stream[sno].status = Free_Stream_f;
-  return t;
-}
-
-Term
-Yap_TermToString(Term t, char *s, unsigned int sz, int flags)
-{
-  int sno = open_buf_write_stream(s, sz);
-  int old_output_stream = Yap_c_output_stream;
-
-  if (sno < 0)
-    return FALSE;
-  Yap_c_output_stream = sno;
-  Yap_StartSlots();
-  Yap_plwrite (t, Stream[sno].stream_wputc, flags, 1200);
-  Yap_CloseSlots();
-  s[Stream[sno].u.mem_string.pos] = '\0';
-  LOCK(Stream[sno].streamlock);
-  Stream[sno].status = Free_Stream_f;
-  UNLOCK(Stream[sno].streamlock);
-  Yap_c_output_stream = old_output_stream;
-  return EX != NULL;
-}
 
 FILE *
 Yap_FileDescriptorFromStream(Term t)
@@ -6163,7 +5704,6 @@ Yap_FileDescriptorFromStream(Term t)
   if (sno < 0)
     return NULL;
   if (Stream[sno].status & (Null_Stream_f|
-		InMemory_Stream_f|
 		Socket_Stream_f|
 		Pipe_Stream_f|
 		Free_Stream_f))
@@ -6202,12 +5742,6 @@ Yap_InitIOPreds(void)
   Yap_InitCPred ("$access", 1, p_access, SafePredFlag|SyncPredFlag|HiddenPredFlag);
   Yap_InitCPred ("exists_directory", 1, p_exists_directory, SafePredFlag|SyncPredFlag);
   Yap_InitCPred ("$file_expansion", 2, p_file_expansion, SafePredFlag|SyncPredFlag|HiddenPredFlag);
-  Yap_InitCPred ("$open_pipe_stream", 2, p_open_pipe_stream, SafePredFlag|SyncPredFlag|HiddenPredFlag);
-  CurrentModule = CHARSIO_MODULE;
-  Yap_InitCPred ("open_mem_read_stream", 2, p_open_mem_read_stream, SyncPredFlag);
-  Yap_InitCPred ("open_mem_write_stream", 1, p_open_mem_write_stream, SyncPredFlag);
-  Yap_InitCPred ("peek_mem_write_stream", 3, p_peek_mem_write_stream, SyncPredFlag);
-  CurrentModule = cm;
   Yap_InitCPred ("$put", 2, p_put, SafePredFlag|SyncPredFlag|HiddenPredFlag);
   Yap_InitCPred ("$put_byte", 2, p_put_byte, SafePredFlag|SyncPredFlag|HiddenPredFlag);
   Yap_InitCPred ("$set_read_error_handler", 1, p_set_read_error_handler, SafePredFlag|SyncPredFlag|HiddenPredFlag);
diff --git a/H/Yapproto.h b/H/Yapproto.h
index 72c91392c..69a169e46 100755
--- a/H/Yapproto.h
+++ b/H/Yapproto.h
@@ -259,7 +259,9 @@ void	STD_PROTO(Yap_InitIOPreds,(void));
 extern void Yap_DebugPlWrite (Term t);
 extern void Yap_DebugErrorPutc (int n);
 #endif
-
+int	STD_PROTO(Yap_LookupSWIStream,(void *));
+int     STD_PROTO(Yap_readTerm, (int, Term *, Term *, Term *, Term *));
+void    STD_PROTO(Yap_PlWriteToStream, (Term, int, int));
 /* depth_lim.c */
 void	STD_PROTO(Yap_InitItDeepenPreds,(void));
 
diff --git a/H/iopreds.h b/H/iopreds.h
index dd043ae60..ddff9dd24 100644
--- a/H/iopreds.h
+++ b/H/iopreds.h
@@ -125,7 +125,6 @@ StreamDesc;
 #define Client_Socket_Stream_f	0x008000
 #define Server_Socket_Stream_f	0x010000
 #endif
-#define InMemory_Stream_f	0x020000
 #define Pipe_Stream_f		0x040000
 #define Popen_Stream_f		0x080000
 #define User_Stream_f		0x100000
diff --git a/Makefile.in b/Makefile.in
index 585423142..52e7098cb 100755
--- a/Makefile.in
+++ b/Makefile.in
@@ -205,6 +205,7 @@ IOLIB_SOURCES=$(srcdir)/packages/PLStream/pl-buffer.c $(srcdir)/packages/PLStrea
 	$(srcdir)/packages/PLStream/pl-option.c  \
 	$(srcdir)/packages/PLStream/pl-os.c \
 	$(srcdir)/packages/PLStream/pl-privitf.c \
+	$(srcdir)/packages/PLStream/pl-read.c \
 	$(srcdir)/packages/PLStream/pl-stream.c $(srcdir)/packages/PLStream/pl-string.c \
 	$(srcdir)/packages/PLStream/pl-table.c \
 	$(srcdir)/packages/PLStream/pl-text.c \
@@ -322,6 +323,7 @@ YAPDOCS=$(srcdir)/docs/yap.tex $(srcdir)/docs/chr.tex \
 IOLIB_OBJECTS=pl-buffer.o pl-codelist.o pl-ctype.o pl-dtoa.o pl-error.o  \
 	pl-file.o pl-files.o pl-fmt.o \
 	pl-glob.o pl-option.o \
+	pl-read.o \
 	pl-os.o pl-privitf.o \
 	pl-stream.o pl-string.o pl-table.o \
 	pl-text.o pl-util.o pl-utf8.o \
@@ -585,6 +587,9 @@ pl-os.o: $(srcdir)/packages/PLStream/pl-os.c
 pl-privitf.o: $(srcdir)/packages/PLStream/pl-privitf.c
 	$(CC) -c $(CFLAGS) -I$(srcdir)/include  -I$(srcdir)  -I$(srcdir)/packages/PLStream $(srcdir)/packages/PLStream/pl-privitf.c -o $@
 
+pl-read.o: $(srcdir)/packages/PLStream/pl-read.c
+	$(CC) -c $(CFLAGS) -I$(srcdir)/include  -I$(srcdir)  -I$(srcdir)/packages/PLStream $(srcdir)/packages/PLStream/pl-read.c -o $@
+
 pl-stream.o: $(srcdir)/packages/PLStream/pl-stream.c
 	$(CC) -c $(CFLAGS) -I$(srcdir)/include  -I$(srcdir)  -I$(srcdir)/packages/PLStream $(srcdir)/packages/PLStream/pl-stream.c -o $@
 
diff --git a/library/charsio.yap b/library/charsio.yap
index 0c7b67d11..6b4ed1a91 100644
--- a/library/charsio.yap
+++ b/library/charsio.yap
@@ -32,86 +32,69 @@
  term_to_atom/2 
     ]).
 
+:- use_module(library(memfile)).
+
 :- meta_predicate(with_output_to_chars(0,?)).
 :- meta_predicate(with_output_to_chars(0,-,?)).
 :- meta_predicate(with_output_to_chars(0,-,?,?)).
 
-format_to_chars(Form, Args, OUT) :-
-	format_to_chars(Form, Args, OUT, []).
+format_to_chars(Format, Args, Codes) :-
+	format(codes(Codes), Format, Args).
 
-format_to_chars(Form, Args, OUT, L0) :-
-	open_mem_write_stream(Stream),
-	format(Stream,Form,Args),
-	peek_mem_write_stream(Stream, L0, O),
-	close(Stream),
-	O = OUT.
+format_to_chars(Format, Args, OUT, L0) :-
+	format(codes(OUT, L0), Format, Args).
+
+write_to_chars(Term, Codes) :-
+	format(codes(Codes), '~w', [Term]).
+
+write_to_chars(Term, Out, Tail) :-
+	format(codes(Out,Tail),'~w',[Term]).
 
-write_to_chars(Term, OUT) :-
-	write_to_chars(Term, [], OUT).
 
 atom_to_chars(Atom, OUT) :-
-	atom_to_chars(Atom, [], OUT).
+	atom_codes(Atom, OUT).
 
 atom_to_chars(Atom, L0, OUT) :-
-	var(Atom), !,
-	throw(error(instantiation_error,atom_to_chars(Atom, L0, OUT))).
-atom_to_chars(Atom, L0, OUT) :-
-	atom(Atom), !,
-	open_mem_write_stream(Stream),
-	write(Stream, Atom),
-	peek_mem_write_stream(Stream, L0, O),
-	close(Stream),
-	O = OUT.
-atom_to_chars(Atom, L0, OUT) :-
-	throw(error(type_error(atom,Atom),atom_to_chars(Atom, L0, OUT))).
+	format(codes(L0, OUT), '~a', [Atom]).
 
 number_to_chars(Number, OUT) :-
-	number_to_chars(Number, [], OUT).
+	number_codes(Number, OUT).
 
 number_to_chars(Number, L0, OUT) :-
 	var(Number), !,
 	throw(error(instantiation_error,number_to_chars(Number, L0, OUT))).
 number_to_chars(Number, L0, OUT) :-
 	number(Number), !,
-	open_mem_write_stream(Stream),
-	write(Stream, Number),
-	peek_mem_write_stream(Stream, L0, O),
-	close(Stream),
-	O = OUT.
+	format(codes(L0, OUT), '~w', [Number]).
 number_to_chars(Number, L0, OUT) :-
 	throw(error(type_error(number,Number),number_to_chars(Number, L0, OUT))).
 
-open_chars_stream(Chars, Stream) :-
-	open_mem_read_stream(Chars, Stream).
+open_chars_stream(Codes, Stream) :-
+	open_chars_stream(Codes, Stream, '').
 
-with_output_to_chars(Goal, Chars) :-
-	with_output_to_chars(Goal, [], Chars).
+open_chars_stream(Codes, Stream, Postfix) :-
+	new_memory_file(MF),
+	open_memory_file(MF, write, Out),
+	format(Out, '~s~w', [Codes, Postfix]),
+	close(Out),
+	open_memory_file(MF, read, Stream,
+			 [ free_on_close(true)
+			 ]).
 
-with_output_to_chars(Goal, L0, Chars) :-
-	with_output_to_chars(Goal, Stream, L0, Chars),
-	close(Stream).
-
-with_output_to_chars(Goal, Stream, L0, Chars) :-
-	open_mem_write_stream(Stream),
-	current_output(SO),
-	set_output(Stream),
-	do_output_to_chars(Goal, Stream, L0, Chars, SO).
-
-do_output_to_chars(Goal, Stream, L0, Chars, SO) :-
-	catch(Goal, Exception, handle_exception(Exception,Stream,SO)),
-	!,
-	set_output(SO),
-	peek_mem_write_stream(Stream, L0, Chars).
-do_output_to_chars(_Goal, Stream, _L0, _Chars, SO) :-
-	set_output(SO),
-	close(Stream),
-	fail.
-
-handle_exception(Exception, Stream, SO) :-
-	close(Stream),
-	current_output(SO),
-	throw(Exception).
+with_output_to_chars(Goal, Codes) :-
+	with_output_to(codes(Codes), Goal).
 
+with_output_to_chars(Goal, Codes, L0) :-
+	with_output_to(codes(Codes, L0), Goal).
+%%	with_output_to_chars(:Goal, -Stream, -Codes, ?Tail) is det.
+%
+%	As  with_output_to_chars/2,  but  Stream  is  unified  with  the
+%	temporary stream.
 
+with_output_to_chars(Goal, Stream, Codes, Tail) :-
+	with_output_to(codes(Codes, Tail), with_stream(Stream, Goal)).
 
+with_stream(Stream, Goal) :-
+	current_output(Stream),
+	call(Goal).
 
diff --git a/library/dialect/swi/fli/swi.c b/library/dialect/swi/fli/swi.c
index cf466a909..27912abf9 100755
--- a/library/dialect/swi/fli/swi.c
+++ b/library/dialect/swi/fli/swi.c
@@ -156,18 +156,6 @@ X_API char* PL_atom_nchars(atom_t a, size_t *len)	 /* SAM check type */
   return s;
 }
 
-X_API int
-PL_chars_to_term(const char *s, term_t term) { 
-  YAP_Term t,error;
-  if ( (t=YAP_ReadBuffer(s,&error))==0L ) {
-    Yap_PutInSlot(term, error); 
-    return 0L;
-  }
-  Yap_PutInSlot(term,t);
-  return 1L;
-}
-
-
 /* SWI: term_t PL_copy_term_ref(term_t from)
    YAP: NO EQUIVALENT */
 /* SAM TO DO */
@@ -1512,7 +1500,7 @@ X_API int PL_unify_term(term_t l,...)
 	*pt++ = MkIntegerTerm((Int)va_arg(ap, void *));
 	break;
       case PL_INT64:
-#if SIZE_OF_LONG_INT==8
+#if SIZEOF_LONG_INT==8
 	*pt++ = MkIntegerTerm((Int)va_arg(ap, long int));
 #elif USE_GMP
 	{
@@ -2745,6 +2733,67 @@ Yap_swi_install(void)
   YAP_UserCPredicate("ctime", SWI_ctime, 2);
 }
 
+int Yap_read_term(term_t t, IOSTREAM *st, term_t vs);
+
+int
+Yap_read_term(term_t t, IOSTREAM *st, term_t vs)
+{
+  int sno = Yap_LookupSWIStream(st);
+  Term varnames, out, tpos;
+
+  if (!Yap_readTerm(sno, &out, &varnames, NULL, &tpos))
+    return FALSE;
+  if (!Yap_unify(out, Yap_GetFromSlot(t))) {
+    return FALSE;
+  }
+  if (!Yap_unify(vs, Yap_GetFromSlot(varnames))) {
+    return FALSE;
+  }
+  return TRUE;
+}
+
+Term
+Yap_StringToTerm(char *s, Term *tp)
+{
+  IOSTREAM *stream = Sopen_string(NULL, s, -1, "r");
+  int sno;
+  Term out, tpos;
+
+  if (!stream)
+    return FALSE;
+  sno = Yap_LookupSWIStream(stream);
+  if (sno < 0)
+    return FALSE;
+  if (!Yap_readTerm(sno, &out, NULL, tp, &tpos)) {
+    out = 0L;
+  }
+  Yap_CloseStream(sno);
+  Sclose(stream);
+  return out;
+}
+
+Term
+Yap_TermToString(Term t, char *s, unsigned int sz, int flags)
+{
+  int old_output_stream = Yap_c_output_stream;
+  IOSTREAM *stream = Sopen_string(NULL, s, sz, "w");
+  int sno;
+
+  if (!stream)
+    return FALSE;
+  sno = Yap_LookupSWIStream(stream);
+
+  if (sno < 0)
+    return 0L;
+  Yap_c_output_stream = sno;
+  Yap_StartSlots();
+  Yap_PlWriteToStream (t, sno, flags);
+  stream->bufp = '\0';
+  Yap_CloseSlots();
+  Yap_c_output_stream = old_output_stream;
+  return EX != NULL;
+}
+
 #ifdef _WIN32
 
 #include <windows.h>
diff --git a/packages/PLStream/pl-file.c b/packages/PLStream/pl-file.c
index 691199564..f595ac667 100755
--- a/packages/PLStream/pl-file.c
+++ b/packages/PLStream/pl-file.c
@@ -4723,6 +4723,7 @@ init_yap(void)
   PL_register_extensions(PL_predicates_from_files);
   PL_register_extensions(PL_predicates_from_glob);
   PL_register_extensions(PL_predicates_from_write);
+  PL_register_extensions(PL_predicates_from_read);
   PL_register_extensions(foreigns);
   fileerrors = TRUE;
   SinitStreams();
diff --git a/packages/PLStream/pl-incl.h b/packages/PLStream/pl-incl.h
index 57ef4d8d8..e0a561cb7 100755
--- a/packages/PLStream/pl-incl.h
+++ b/packages/PLStream/pl-incl.h
@@ -1104,4 +1104,5 @@ extern const PL_extension PL_predicates_from_file[];
 extern const PL_extension PL_predicates_from_files[];
 extern const PL_extension PL_predicates_from_glob[];
 extern const PL_extension PL_predicates_from_write[];
+extern const PL_extension PL_predicates_from_read[];
 
diff --git a/packages/PLStream/pl-read.c b/packages/PLStream/pl-read.c
new file mode 100644
index 000000000..c9222286c
--- /dev/null
+++ b/packages/PLStream/pl-read.c
@@ -0,0 +1,134 @@
+
+#include "pl-incl.h"
+
+typedef struct
+{
+  term_t	varnames;		/* Report variables+names */  
+  IOSTREAM *stream;
+  int		has_exception;		/* exception is raised */
+
+  term_t	exception;		/* raised exception */
+} read_data, *ReadData;
+
+static void
+init_read_data(ReadData _PL_rd, IOSTREAM *in ARG_LD)
+{ 
+  _PL_rd->varnames = 0;
+  _PL_rd->stream = in;
+}
+
+static void
+free_read_data(ReadData _PL_rd)
+{ 
+}
+
+static int 
+read_term(term_t t, ReadData rd ARG_LD)
+{
+  return Yap_read_term(t, rd->stream, rd->varnames);
+}
+
+
+		 /*******************************
+		 *	   TERM <->ATOM		*
+		 *******************************/
+
+static int
+atom_to_term(term_t atom, term_t term, term_t bindings)
+{ GET_LD
+  PL_chars_t txt;
+
+  if ( !bindings && PL_is_variable(atom) ) /* term_to_atom(+, -) */
+  { char buf[1024];
+    size_t bufsize = sizeof(buf);
+    int rval;
+    char *s = buf;
+    IOSTREAM *stream;
+    PL_chars_t txt;
+
+    stream = Sopenmem(&s, &bufsize, "w");
+    stream->encoding = ENC_UTF8;
+    PL_write_term(stream, term, 1200, PL_WRT_QUOTED);
+    Sflush(stream);
+
+    txt.text.t = s;
+    txt.length = bufsize;
+    txt.storage = PL_CHARS_HEAP;
+    txt.encoding = ENC_UTF8;
+    txt.canonical = FALSE;
+    rval = PL_unify_text(atom, 0, &txt, PL_ATOM);
+
+    Sclose(stream);
+    if ( s != buf )
+      Sfree(s);
+
+    return rval;
+  }
+
+  if ( PL_get_text(atom, &txt, CVT_ALL|CVT_EXCEPTION) )
+  { GET_LD
+    read_data rd;
+    int rval;
+    IOSTREAM *stream;
+    source_location oldsrc = LD->read_source;
+
+    stream = Sopen_text(&txt, "r");
+
+    init_read_data(&rd, stream PASS_LD);
+    if ( bindings && (PL_is_variable(bindings) || PL_is_list(bindings)) )
+      rd.varnames = bindings;
+    else if ( bindings )
+      return PL_error(NULL, 0, NULL, ERR_TYPE, ATOM_list, bindings);
+
+    if ( !(rval = read_term(term, &rd PASS_LD)) && rd.has_exception )
+      rval = PL_raise_exception(rd.exception);
+    free_read_data(&rd);
+    Sclose(stream);
+    LD->read_source = oldsrc;
+
+    return rval;
+  }
+
+  fail;
+}
+
+
+static
+PRED_IMPL("atom_to_term", 3, atom_to_term, 0)
+{ return atom_to_term(A1, A2, A3);
+}
+
+
+static
+PRED_IMPL("term_to_atom", 2, term_to_atom, 0)
+{ return atom_to_term(A2, A1, 0);
+}
+
+
+int
+PL_chars_to_term(const char *s, term_t t)
+{ GET_LD
+  read_data rd;
+  int rval;
+  IOSTREAM *stream = Sopen_string(NULL, (char *)s, -1, "r");
+  source_location oldsrc = LD->read_source;
+
+  init_read_data(&rd, stream PASS_LD);
+  PL_put_variable(t);
+  if ( !(rval = read_term(t, &rd PASS_LD)) && rd.has_exception )
+    PL_put_term(t, rd.exception);
+  free_read_data(&rd);
+  Sclose(stream);
+  LD->read_source = oldsrc;
+
+  return rval;
+}
+
+		 /*******************************
+		 *      PUBLISH PREDICATES	*
+		 *******************************/
+
+BeginPredDefs(read)
+  PRED_DEF("atom_to_term", 3, atom_to_term, 0)
+  PRED_DEF("term_to_atom", 2, term_to_atom, 0)
+EndPredDefs
diff --git a/packages/PLStream/pl-yap.h b/packages/PLStream/pl-yap.h
index 5d12751b8..709391210 100644
--- a/packages/PLStream/pl-yap.h
+++ b/packages/PLStream/pl-yap.h
@@ -29,8 +29,9 @@ typedef YAP_Term	       *Word;		/* Anonymous 4 byte object */
 typedef YAP_Atom		Atom;
 typedef YAP_Term		(*Func)(term_t);	/* foreign functions */
 
-const char *Yap_GetCurrentPredName(void);
-YAP_Int     Yap_GetCurrentPredArity(void);
+extern const char *Yap_GetCurrentPredName(void);
+extern YAP_Int     Yap_GetCurrentPredArity(void);
+extern int Yap_read_term(term_t t, IOSTREAM *st, term_t *vs);
 
 
 extern atom_t codeToAtom(int chrcode);
diff --git a/pl/boot.yap b/pl/boot.yap
index 12f3bc7b3..832bebf5d 100755
--- a/pl/boot.yap
+++ b/pl/boot.yap
@@ -712,11 +712,8 @@ true :- true.
 	'$write_goal_output'(G1, First, NG, Next, IG),
 	'$write_vars_and_goals'(LG, Next, IG).
 
-'$goal_to_string'(Format, G, String) :-			  
-	charsio:open_mem_write_stream(W),
-        format(W,Format,G),
-	charsio:peek_mem_write_stream(W, [], String),
-	close(W).
+'$goal_to_string'(Format, G, String) :-
+	format(codes(String),Format,G).
 
 '$write_goal_output'(var([V|VL]), First, [var([V|VL])|L], next, L) :- !,
         ( First = first -> true ; format(user_error,',~n',[]) ),
@@ -1393,3 +1390,10 @@ open_null_stream(S) :-
 stream_property(Stream, Property) :-
 	swi_stream_property(Stream, Property).
 
+atom_to_term(Atom, Term, Bindings) :-
+	swi_atom_to_term(Atom, Term, Bindings).
+term_to_atom(Term, Atom) :-
+	swi_term_to_atom(Term, Atom).
+
+with_output_to(Output, G) :-
+	swi_with_output_to(Output, G).
\ No newline at end of file
diff --git a/pl/consult.yap b/pl/consult.yap
index 0a91786ab..06b72753f 100755
--- a/pl/consult.yap
+++ b/pl/consult.yap
@@ -430,7 +430,8 @@ initialization(G,OPT) :-
 	nb_setval('$included_file', Y),
 	'$current_module'(Mod),
 	H0 is heapused, '$cputime'(T0,_),
-	'$default_encoding'(Encoding),
+	'$default_encoding'(Enc),
+	'$valid_encoding'(Encoding, Enc),
 	( open(Y, read, Stream, [encoding(Encoding)]), !,  % '$open'(Y, '$csult', Stream, 0, Encoding, X), !,
 		print_message(Verbosity, loading(including, Y)),
 		'$loop'(Stream,Status), '$close'(Stream)
@@ -826,11 +827,7 @@ absolute_file_name(File,Opts,TrueFileName) :-
 	File = File0.
 '$cat_file_name'(File0,File) :-
 	ground(File0),
-	charsio:open_mem_write_stream(Stream),
-	write(Stream, File0),
-	charsio:peek_mem_write_stream(Stream, [], L),
-	close(Stream),
-	atom_codes(File, L).
+	format(atom(File), '~w', [File0]).
 
 '$get_abs_file'(File,opts(_,D0,_,_,_,_,_),AbsFile) :-
 	operating_system_support:true_file_name(File,D0,AbsFile).
diff --git a/pl/control.yap b/pl/control.yap
index 1867b363b..c8dbd9232 100644
--- a/pl/control.yap
+++ b/pl/control.yap
@@ -301,15 +301,7 @@ prolog_current_frame(Env) :-
 
 '$run_atom_goal'(GA) :-
 	'$current_module'(Module),
-	atom_codes(GA,Gs0),
-	'$add_dot_to_atom_goal'(Gs0,Gs),
-	charsio:open_mem_read_stream(Gs, Stream),
-	( '$system_catch'(read(Stream, G),Module,_,fail) ->
-	    close(Stream)
-	;
-	    close(Stream),
-	    fail
-	),
+	atom_to_term(GA, G, _),
 	'$system_catch'('$query'(once(G), []),Module,Error,user:'$Error'(Error)).
 
 '$add_dot_to_atom_goal'([],[0'.]) :- !. %'
diff --git a/pl/utils.yap b/pl/utils.yap
index 09d963743..3c45c2b9f 100644
--- a/pl/utils.yap
+++ b/pl/utils.yap
@@ -661,42 +661,6 @@ sub_atom(At, Bef, Size, After, SubAt) :-
 '$subtract_lists_of_variables'([V1|VL1],[V2|VL2],[V2|VL]) :-
 	'$subtract_lists_of_variables'([V1|VL1],VL2,VL).
 
-atom_to_term(Atom, Term, Bindings) :-
-	atom_codes(Atom, Chars),
-	charsio:open_mem_read_stream(Chars, Stream),
-	catch(read_term(Stream, T, [variable_names(Bindings)]),Error,'$handle_atom_to_term_error'(Stream, Error)),
-	close(Stream),
-	T = Term.
-
-'$handle_atom_to_term_error'(Stream, Error) :-
-	close(Stream),
-	throw(Error).
-
-term_to_atom(Term,Atom) :-
-	nonvar(Atom), !,
-	atom_codes(Atom,S),
-	charsio:read_from_chars(S,Term).
-term_to_atom(Term,Atom) :-
-	charsio:write_to_chars(Term,S),
-	atom_codes(Atom,S).
-
-%
-% hack this here.
-%
-charsio:write_to_chars(Term, L0, OUT) :-
-	charsio:open_mem_write_stream(Stream),
-	prolog:write(Stream, Term),
-	charsio:peek_mem_write_stream(Stream, L0, O),
-	prolog:close(Stream),
-	O = OUT.
-
-charsio:read_from_chars(Chars, Term) :-
-	charsio:open_mem_read_stream(Chars, Stream),
-	prolog:read(Stream, T),
-	prolog:close(Stream),
-	T = Term.
-
-
 simple(V) :- var(V), !.
 simple(A) :- atom(A), !.
 simple(N) :- number(N).
diff --git a/pl/yio.yap b/pl/yio.yap
index b517fe060..1455fbc09 100644
--- a/pl/yio.yap
+++ b/pl/yio.yap
@@ -168,9 +168,15 @@ set_input(Stream) :-
 set_output(Stream) :-
 	'$set_output'(Stream).
 
-open_null_stream(S) :- '$open_null_stream'(S).
-
-open_pipe_streams(P1,P2) :- '$open_pipe_stream'(P1, P2).
+open_pipe_streams(Read, Write) :-
+	(
+	 '$undefined'(pipe(_,_),unix)
+	->
+	 load_files(library(unix), [silent(true),if(not_loaded)])
+	;
+	 true
+	),
+	unix:pipe(Read, Write).
 
 fileerrors :- set_value(fileerrors,1).
 nofileerrors :- set_value(fileerrors,0).
@@ -794,36 +800,10 @@ current_stream(File, Opts, Stream) :-
 
 
 '$format@'(Goal,Out) :-
-	'$with_output_to_chars'(Goal, _, [], Out).
-
-'$with_output_to_chars'(Goal, Stream, L0, Chars) :-
-	charsio:open_mem_write_stream(Stream),
-	current_output(SO),
-	set_output(Stream),
-	'$do_output_to_chars'(Goal, Stream, L0, Chars, SO).
-
-'$do_output_to_chars'(Goal, Stream, L0, Chars, SO) :-
-	catch(Goal, Exception, '$handle_exception'(Exception,Stream,SO)),
-	!,
-	set_output(SO),
-	charsio:peek_mem_write_stream(Stream, L0, Chars),
-	close(Stream).
-'$do_output_to_chars'(_Goal, Stream, _L0, _Chars, SO) :-
-	set_output(SO),
-	close(Stream),
-	fail.
+	with_output_to(codes(Out), Goal).
 
 sformat(String, Form, Args) :-
-	charsio:open_mem_write_stream(Stream),
-	format(Stream, Form, Args),
-	charsio:peek_mem_write_stream(Stream, [], String),
-	close(Stream).
-
-
-'$handle_exception'(Exception, Stream, SO) :-
-	set_output(SO),
-	close(Stream),
-	throw(Exception).
+	format(codes(String, []), Form, Args).
 
 write_depth(T,L) :- write_depth(T,L,_).
 
@@ -855,57 +835,6 @@ prolog_file_name(File, PrologFileName) :-
 prolog_file_name(File, PrologFileName) :-
 	'$do_error'(type_error(atom,T), prolog_file_name(File, PrologFileName)).
 
-with_output_to(Output, Command) :-
-	setup_call_cleanup( '$setup_wot'(Output, Stream, OldStream, with_output_to(Output, Command)),
-			    once(Command),
-			    '$cleanup_wot'(Output, Stream, OldStream) ).
-
-'$setup_wot'(Output, Stream, OldStream, Goal) :-
-	'$setup_wot'(Output, Stream, Goal),
-	current_output(OldStream),
-	set_output(Stream).
-
-'$setup_wot'(Output, Stream, Goal) :-
-	var(Output), !,
-	'$do_error'(instantiation_error,Goal).
-'$setup_wot'(atom(_Atom), Stream, _) :- !,
-	charsio:open_mem_write_stream(Stream).
-'$setup_wot'(codes(_Codes), Stream, _) :- !,
-	charsio:open_mem_write_stream(Stream).
-'$setup_wot'(codes(_Codes, _Tail), Stream, _) :- !,
-	charsio:open_mem_write_stream(Stream).
-'$setup_wot'(chars(_Chars), Stream, _) :- !,
-	charsio:open_mem_write_stream(Stream).
-'$setup_wot'(chars(_Chars, _Tail), Stream, _) :- !,
-	charsio:open_mem_write_stream(Stream).
-'$setup_wot'(Stream, Stream, _) :-
-	'$stream'(Stream), !.
-'$setup_wot'(Output, _, Goal) :-
-	'$do_error'(type_error(output,Output),Goal).
-
-'$cleanup_wot'(Output, Stream, OldStream) :- !,
-	'$cleanup_wot'(Output, Stream),
-	set_output(OldStream).
-
-'$cleanup_wot'(atom(Atom), Stream) :- !,
-	charsio:peek_mem_write_stream(Stream, [], String),
-	atom_codes(Atom, String),
-	close(Stream).
-'$cleanup_wot'(codes(Codes), Stream) :- !,
-	charsio:peek_mem_write_stream(Stream, [], Codes),
-	close(Stream).
-'$cleanup_wot'(codes(Codes, Tail), Stream) :- !,
-	charsio:peek_mem_write_stream(Stream, Tail, Codes),
-	close(Stream).
-'$cleanup_wot'(chars(Chars), Stream) :- !,
-	charsio:peek_mem_write_stream(Stream, [], String),
-	'$codes_to_chars'([], String, Chars),
-	close(Stream).
-'$cleanup_wot'(chars(Chars, Tail), Stream) :- !,
-	charsio:peek_mem_write_stream(Stream, Tail, String),
-	'$codes_to_chars'(Tail, String, Chars),
-	close(Stream).
-'$cleanup_wot'(_, _).
 
 '$codes_to_chars'(String0, String, String0) :- String0 == String, !.
 '$codes_to_chars'(String0, [Code|String], [Char|Chars]) :-