diff --git a/C/alloc.c b/C/alloc.c
index 379172bdd..03daf3d82 100644
--- a/C/alloc.c
+++ b/C/alloc.c
@@ -12,7 +12,7 @@
 * Last rev:								 *
 * mods:									 *
 * comments:	allocating space					 *
-* version:$Id: alloc.c,v 1.54 2004-07-23 21:08:44 vsc Exp $		 *
+* version:$Id: alloc.c,v 1.55 2004-07-28 22:09:01 vsc Exp $		 *
 *************************************************************************/
 #ifdef SCCS
 static char SccsId[] = "%W% %G%";
@@ -563,22 +563,22 @@ Yap_ExpandPreAllocCodeSpace(UInt sz)
 
 #define BASE_ADDRESS  ((LPVOID) MMAP_ADDR)
 /* #define MAX_WORKSPACE 0x40000000L */
-#define MAX_WORKSPACE 0x20000000L
+#define MAX_WORKSPACE 0x80000000L
 
 static LPVOID brk;
 
 static int
 ExtendWorkSpace(Int s)
 {
-  LPVOID b;
+  LPVOID b = brk;
   prolog_exec_mode OldPrologMode = Yap_PrologMode;
 
   Yap_PrologMode = ExtendStackMode;
-  b = VirtualAlloc(brk, s, MEM_COMMIT, PAGE_READWRITE);
+  b = VirtualAlloc(b, s, MEM_COMMIT, PAGE_READWRITE);
   if (b) {
-  	brk = (LPVOID) ((Int) brk + s);
-	Yap_PrologMode = OldPrologMode;
-	return TRUE;
+    brk = (LPVOID) ((Int) brk + s);
+    Yap_PrologMode = OldPrologMode;
+    return TRUE;
   }
   Yap_ErrorMessage = Yap_ErrorSay;
   snprintf4(Yap_ErrorMessage, MAX_ERROR_MSG_SIZE,
@@ -592,27 +592,32 @@ static MALLOC_T
 InitWorkSpace(Int s)
 {
   SYSTEM_INFO si;
-  LPVOID b;
+  UInt max_mem = MAX_WORKSPACE;
+  LPVOID b = NULL;
 
   GetSystemInfo(&si);
   Yap_page_size = si.dwPageSize;
-  b = VirtualAlloc(BASE_ADDRESS, MAX_WORKSPACE, MEM_RESERVE, PAGE_NOACCESS);
-  if (b==NULL) {
-    b = VirtualAlloc(0x0, MAX_WORKSPACE, MEM_RESERVE, PAGE_NOACCESS);
-    if (b == NULL) {
-      Yap_Error(FATAL_ERROR,TermNil,"VirtualAlloc failed");
-      return(0);
-    }
-    fprintf(stderr,"%% Warning: YAP reserving space at variable address %p\n", b);
-  }
-  brk = BASE_ADDRESS;
 
-  if (ExtendWorkSpace(s)) {
-    return BASE_ADDRESS;
-  } else {
-    Yap_Error(FATAL_ERROR,TermNil,"VirtualAlloc Failed");
-    return(0);
+  brk = NULL;
+  for (max_mem = MAX_WORKSPACE; max_mem >= s; max_mem = max_mem - (max_mem >> 2)) {
+    b = VirtualAlloc((LPVOID)MMAP_ADDR, max_mem, MEM_RESERVE, PAGE_NOACCESS);
+    if (b == NULL) {
+      b = VirtualAlloc(NULL, max_mem, MEM_RESERVE, PAGE_NOACCESS);
+      if (b != NULL) {
+	brk = b;
+	fprintf(stderr,"%% Warning: YAP reserving space at variable address %p\n", brk);
+	break;
+      } 
+    } else {
+      brk = BASE_ADDRESS;
+      break;
+    }
   }
+  if (brk && ExtendWorkSpace(s)) {
+    return (MALLOC_T)b;
+  }
+  Yap_Error(FATAL_ERROR,TermNil,"VirtualAlloc Failed");
+  return NULL;
 }
 
 int
@@ -1193,6 +1198,7 @@ InitHeap(void *heap_addr)
   HeapTop = Yap_HeapBase + AdjustSize(sizeof(all_heap_codes));
   HeapMax = HeapUsed = HeapTop-Yap_HeapBase;
 
+
   /* notice that this forces odd addresses */
   *((YAP_SEG_SIZE *) HeapTop) = InUseFlag;
   HeapTop = HeapTop + sizeof(YAP_SEG_SIZE);
@@ -1286,7 +1292,6 @@ Yap_InitMemory(int Trail, int Heap, int Stack)
 #endif /* SHORT_INTS */
   }
 #endif /* DEBUG */
-
 }
 
 void
diff --git a/C/dbase.c b/C/dbase.c
index abf5dc459..c1534d4b9 100644
--- a/C/dbase.c
+++ b/C/dbase.c
@@ -2319,10 +2319,15 @@ p_still_variant(void)
   }
   /* ok, we assume there was a choicepoint before we copied the term */
 
+  /* skip binding for argument variable */
+  old_tr++;
   if (dbr->Flags & LogUpdMask) {
     LogUpdClause *cl = (LogUpdClause *)dbr;
 
-    if (old_tr != TR-2)
+    if (old_tr == TR-1) {
+      if (TrailTerm(old_tr) != CLREF_TO_TRENTRY(cl))
+	return FALSE;
+    } else if (old_tr != TR)
       return FALSE;
     if (Yap_op_from_opcode(cl->ClCode->opc) == _unify_idb_term) {
       return TRUE;
@@ -2330,7 +2335,10 @@ p_still_variant(void)
       dbt = cl->ClSource;
     }
   } else {
-    if (old_tr != TR-2)
+    if (old_tr == TR-1) {
+      if (TrailTerm(old_tr) != REF_TO_TRENTRY(dbr))
+	return FALSE;
+    } else if (old_tr != TR)
       return FALSE;
     if (dbr->Flags & (DBNoVars|DBAtomic))
       return TRUE;
@@ -2339,6 +2347,10 @@ p_still_variant(void)
     dbt = &(dbr->DBT);
   }
 #ifdef IDB_LINK_TABLE
+  /*
+    we checked the trail, so we are sure only variables in the new term
+    were bound
+  */
   {
     link_entry *lp = (link_entry *)(dbt->Contents+dbt->NOfCells);
     link_entry link;
diff --git a/C/iopreds.c b/C/iopreds.c
index d3b6bf351..636d54dac 100644
--- a/C/iopreds.c
+++ b/C/iopreds.c
@@ -650,7 +650,12 @@ MemPutc(int sno, int ch)
     char *newbuf;
 
     if ((newbuf = Yap_AllocAtomSpace(new_max_size*sizeof(char))) == NULL) {
-      Yap_Error(OUT_OF_HEAP_ERROR, TermNil, "YAP could not grow heap for writing to string");
+      if (Stream[sno].u.mem_string.error_handler) {
+	Yap_Error_Size = new_max_size*sizeof(char);
+	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
@@ -2022,6 +2027,7 @@ open_buf_read_stream(char *nbuf, Int nchars)
   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;
   return sno;
 }
 
@@ -3741,18 +3747,44 @@ format_has_tabs(const char *seq)
 }
 
 static Int
-format(Term tail, Term args, int sno)
+format(volatile Term otail, volatile Term oargs, int sno)
 {
   char tmp1[256], tmp2[256];
   int ch;
-  int column_boundary = 0;
+  int column_boundary;
   Term mytargs[8], *targs;
-  Int tnum, targ = 0;
+  Int tnum, targ;
   char *fstr = NULL, *fptr;
-  Term oargs = args;
+  Term args;
+  Term tail;
   int (* f_putc)(int, int);
   int has_tabs;
+  jmp_buf format_botch;
+  void *old_handler;
+  volatile int old_pos;
 
+  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)) {
+      *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;
+    }
+  }
+  args = oargs;
+  tail = otail;
+  targ = 0;
+  column_boundary = 0;
   if (IsVarTerm(tail)) {
     Yap_Error(INSTANTIATION_ERROR,tail,"format/2");
     return(FALSE);
@@ -4052,6 +4084,9 @@ format(Term tail, Term args, int sno)
 	      if (IsAtomTerm(tail)) {
 		fstr = NULL;
 	      }
+	      if (Stream[sno].status & InMemory_Stream_f) {
+		old_handler = Stream[sno].u.mem_string.error_handler;
+	      }
 	      format_clean_up(format_base, fstr, targs);
 	      Yap_JumpToEnv(ball);
 	    }
@@ -4157,6 +4192,9 @@ format(Term tail, Term args, int sno)
 	    if (IsAtomTerm(tail)) {
 	      fstr = NULL;
 	    }
+	    if (Stream[sno].status & InMemory_Stream_f) {
+	      old_handler = Stream[sno].u.mem_string.error_handler;
+	    }
 	    format_clean_up(format_base, fstr, targs);
 	    return FALSE;
 	  }
@@ -4177,6 +4215,9 @@ format(Term tail, Term args, int sno)
   }
   if (tnum <= 8)
     targs = NULL;
+  if (Stream[sno].status & InMemory_Stream_f) {
+    old_handler = Stream[sno].u.mem_string.error_handler;
+  }
   format_clean_up(format_base, fstr, targs);
   return (TRUE);
 }
diff --git a/H/iopreds.h b/H/iopreds.h
index ff6caca4f..a36db8a85 100644
--- a/H/iopreds.h
+++ b/H/iopreds.h
@@ -37,12 +37,18 @@ typedef struct stream_desc
       struct {
 	Atom name;
 	Term user_name;
+#if defined(__MINGW32__) || _MSC_VER
+#define PLGETC_BUF_SIZE 4096
+	char *buf, *ptr;
+	int left;
+#endif
 	YP_File file;
       } file;
       struct {
 	char *buf;         /* where the file is being read from/written to */
 	Int max_size;	   /* maximum buffer size (may be changed dynamically) */
 	Int pos;
+	void *error_handler;
       } mem_string;
       struct {
 #if defined(__MINGW32__) || _MSC_VER
diff --git a/m4/Yap.h.m4 b/m4/Yap.h.m4
index e668d4113..71fec1a91 100644
--- a/m4/Yap.h.m4
+++ b/m4/Yap.h.m4
@@ -10,7 +10,7 @@
 * File:		Yap.h.m4						 *
 * mods:									 *
 * comments:	main header file for YAP				 *
-* version:      $Id: Yap.h.m4,v 1.61 2004-07-26 16:03:35 vsc Exp $	 *
+* version:      $Id: Yap.h.m4,v 1.62 2004-07-28 22:09:02 vsc Exp $	 *
 *************************************************************************/
 
 #include "config.h"
@@ -251,6 +251,7 @@ extern char     Yap_Option[20];
 #if !IN_SECOND_QUADRANT
 #if __linux__ || __FreeBSD__ || __NetBSD__ || mips || __APPLE__
 #if defined(YAPOR) && defined(__alpha)
+
 #define MMAP_ADDR 0x40000000
 #elif mips
 #define MMAP_ADDR 0x02000000
@@ -262,7 +263,7 @@ extern char     Yap_Option[20];
 #elif __svr4__ || defined(__SVR4)
 #define MMAP_ADDR 0x02000000
 #elif defined(_WIN32)
-#define MMAP_ADDR 0x18000000L
+#define MMAP_ADDR 0x10040000L
 #elif defined(__CYGWIN__)
 #define MMAP_ADDR 0x30000000L
 #endif
@@ -272,7 +273,7 @@ extern char     Yap_Option[20];
 #define HEAP_INIT_BASE  0L
 #define AtomBase        NULL
 #else
-#if defined(MMAP_ADDR) && (USE_MMAP || USE_SHMAT || _WIN32) && !__simplescalar__
+#if defined(MMAP_ADDR) && (USE_MMAP || USE_SHMAT) && !__simplescalar__
 #define HEAP_INIT_BASE  (MMAP_ADDR)
 #define AtomBase        ((char *)MMAP_ADDR)
 #else