diff --git a/cygwin.txt b/cygwin.txt
new file mode 100644
index 000000000..741318489
--- /dev/null
+++ b/cygwin.txt
@@ -0,0 +1,54 @@
+
+This file describes the build procedure under cygwin32 (Windows 95/98/NT/2K)
+----------------------------------------------------------------------------
+To build using cygwin:
+
+Prerequisites:
+
+ o Latest net release (1.1.4) of cygwin (sources.redhat.com/cygwin)
+ o autoconf version 2.13 (or later) from cygutils (cygutils.netpedia.net)
+ o cvs (1.10.8 or later) also from cygutils
+
+Procedure:
+ o Get the source code - see the main icarus verilog page for how to 
+   do this
+ o cd to the verilog directory
+ o autoconf
+ o ./configure
+ o make
+ o make install
+
+That's all that's needed.  But there're two common problems during
+the make phase.  All steps are in the verilog directory.
+
+1. 
+
+If gcc dies saying virtual memory exhausted while compiling parse.c 
+  then recompile with -O1 or without -O flag and do these steps to
+  continue
+     o c++ -DHAVE_GETOPT_H=1 -DUSE_LIBVPIP=1  -g -I. -MD -c parse.cc -o parse.o
+     o mv parse.d dep/parse.d
+     o make
+
+2.
+
+If gcc dies in the vpi directory while compiling vpi_systask.c with the
+  error, conflicting types for `_cygwin_dll_entry', then fix the line in 
+  /usr/include/cygwin/cygwin_dll.h.  Change the line:
+
+  int WINAPI _cygwin_dll_entry (HANDLE h, DWORD reason, void *ptr); \
+to 
+  int WINAPI _cygwin_dll_entry (HINSTANCE h, DWORD reason, void *ptr); \
+
+  Note the change from HANDLE to HINSTANCE.  Then do
+     o make
+
+To build your own extensions - just include vpi_user.h and link with
+a command like this:
+
+ $(CC) -shared -o <dllname> <objects> -Wl,--enable-auto-image-base -L../vvm -lvvm -lvpip
+
+ - Venkat Iyer <venkat@comit.com>
+
+
+
diff --git a/vpi/Makefile.in b/vpi/Makefile.in
index 948059a36..a6104078c 100644
--- a/vpi/Makefile.in
+++ b/vpi/Makefile.in
@@ -18,7 +18,7 @@
 #    59 Temple Place - Suite 330
 #    Boston, MA 02111-1307, USA
 #
-#ident "$Id: Makefile.in,v 1.12 2000/09/30 03:20:47 steve Exp $"
+#ident "$Id: Makefile.in,v 1.13 2000/10/03 16:15:35 steve Exp $"
 #
 #
 SHELL = /bin/sh
@@ -41,7 +41,7 @@ INSTALL = @INSTALL@
 INSTALL_PROGRAM = @INSTALL_PROGRAM@
 INSTALL_DATA = @INSTALL_DATA@
 
-CPPFLAGS = @CPPFLAGS@ @DEFS@ @PICFLAG@ -DBUILD_vpi
+CPPFLAGS = @CPPFLAGS@ @DEFS@ @PICFLAG@
 CXXFLAGS = @CXXFLAGS@
 LDFLAGS = @LDFLAGS@
 
@@ -57,11 +57,13 @@ sys_readmem.o sys_readmem_lex.o sys_vcd.o
 
 ifeq (@CYGWIN@,yes)
   SYSTEM_VPI_LDFLAGS=-Wl,--enable-auto-image-base -L../vvm -lvvm -lvpip
+  VPIP_LIBS = ../vvm/libvvm.a ../vvm/libvpip.a
 else
   SYSTEM_VPI_LDFLAGS=
+  VPIP_LIBS = 
 endif
 
-system.vpi: $O
+system.vpi: $O $(VPIP_LIBS)
 	$(CC) -shared -o $@ $O $(SYSTEM_VPI_LDFLAGS)
 
 sys_readmem_lex.c: sys_readmem_lex.lex
diff --git a/vpi/vpi_user.h b/vpi/vpi_user.h
index 14127a4f6..f6b151161 100644
--- a/vpi/vpi_user.h
+++ b/vpi/vpi_user.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: vpi_user.h,v 1.21 2000/09/30 03:20:48 steve Exp $"
+#ident "$Id: vpi_user.h,v 1.22 2000/10/03 16:15:35 steve Exp $"
 #endif
 
 
@@ -31,22 +31,14 @@
 #  define DLLEXPORT
 #endif
 
-#undef VPI_STORAGE_CLASS
-#if defined(BUILD_vvm)
-# define VVM_STORAGE_CLASS DLLEXPORT
+#undef VPIP_STORAGE_CLASS
+#if defined(__build_vpip)
+# define VPIP_STORAGE_CLASS DLLEXPORT
 #else
-#  define VVM_STORAGE_CLASS DLLIMPORT
+#  define VPIP_STORAGE_CLASS DLLIMPORT
 #endif
 
-#undef VPI_STORAGE_CLASS
-#if defined(BUILD_vpi) 
-# define VPI_STORAGE_CLASS DLLEXPORT
-#else
-#  define VPI_STORAGE_CLASS DLLIMPORT
-#endif
-
-#define VVM_EXTERN extern VVM_STORAGE_CLASS
-#define VPI_EXTERN extern VPI_STORAGE_CLASS
+#define VPIP_EXTERN extern VPIP_STORAGE_CLASS
 
 #ifdef __cplusplus
 extern "C" {
@@ -188,13 +180,13 @@ typedef struct t_vpi_value {
 
 
 /* VPI FUNCTIONS */
-VVM_EXTERN void vpi_register_systf(const struct t_vpi_systf_data*ss);
-VVM_EXTERN void vpi_printf(const char*fmt, ...);
+VPIP_EXTERN void vpi_register_systf(const struct t_vpi_systf_data*ss);
+VPIP_EXTERN void vpi_printf(const char*fmt, ...);
 
-VVM_EXTERN unsigned int vpi_mcd_close(unsigned int mcd);
-VVM_EXTERN char *vpi_mcd_name(unsigned int mcd);
-VVM_EXTERN unsigned int vpi_mcd_open(char *name);
-VVM_EXTERN int vpi_mcd_printf(unsigned int mcd, const char*fmt, ...);
+VPIP_EXTERN unsigned int vpi_mcd_close(unsigned int mcd);
+VPIP_EXTERN char *vpi_mcd_name(unsigned int mcd);
+VPIP_EXTERN unsigned int vpi_mcd_open(char *name);
+VPIP_EXTERN int vpi_mcd_printf(unsigned int mcd, const char*fmt, ...);
 
 /*
  * support for VPI callback functions.
@@ -234,8 +226,8 @@ typedef struct t_cb_data {
 #define cbInteractiveScopeChange 23
 #define cbUnresolvedSystf   24
 
-VVM_EXTERN vpiHandle vpi_register_cb(p_cb_data data);
-VVM_EXTERN int vpi_remove_cb(vpiHandle ref);
+VPIP_EXTERN vpiHandle vpi_register_cb(p_cb_data data);
+VPIP_EXTERN int vpi_remove_cb(vpiHandle ref);
 
 /*
  * This function allows a vpi application to control the simulation
@@ -252,30 +244,30 @@ VVM_EXTERN int vpi_remove_cb(vpiHandle ref);
  * vpiReset -
  * vpiSetInteractiveScope -
  */
-VVM_EXTERN void vpi_sim_control(int operation, ...);
+VPIP_EXTERN void vpi_sim_control(int operation, ...);
 #define vpiStop 1
 #define vpiFinish 2
 #define vpiReset  3
 #define vpiSetInteractiveScope 4
 
-VVM_EXTERN vpiHandle  vpi_handle(int type, vpiHandle ref);
-VVM_EXTERN vpiHandle  vpi_iterate(int type, vpiHandle ref);
-VVM_EXTERN vpiHandle  vpi_scan(vpiHandle iter);
-VVM_EXTERN vpiHandle  vpi_handle_by_index(vpiHandle ref, int index);
+VPIP_EXTERN vpiHandle  vpi_handle(int type, vpiHandle ref);
+VPIP_EXTERN vpiHandle  vpi_iterate(int type, vpiHandle ref);
+VPIP_EXTERN vpiHandle  vpi_scan(vpiHandle iter);
+VPIP_EXTERN vpiHandle  vpi_handle_by_index(vpiHandle ref, int index);
 
-VVM_EXTERN void  vpi_get_time(vpiHandle obj, s_vpi_time*t);
-VVM_EXTERN int   vpi_get(int property, vpiHandle ref);
-VVM_EXTERN char* vpi_get_str(int property, vpiHandle ref);
-VVM_EXTERN void  vpi_get_value(vpiHandle expr, p_vpi_value value);
-VVM_EXTERN vpiHandle vpi_put_value(vpiHandle obj, p_vpi_value value,
+VPIP_EXTERN void  vpi_get_time(vpiHandle obj, s_vpi_time*t);
+VPIP_EXTERN int   vpi_get(int property, vpiHandle ref);
+VPIP_EXTERN char* vpi_get_str(int property, vpiHandle ref);
+VPIP_EXTERN void  vpi_get_value(vpiHandle expr, p_vpi_value value);
+VPIP_EXTERN vpiHandle vpi_put_value(vpiHandle obj, p_vpi_value value,
 			       p_vpi_time when, int flags);
 
-VVM_EXTERN int vpi_free_object(vpiHandle ref);
-VVM_EXTERN int vpi_get_vlog_info(p_vpi_vlog_info vlog_info_p);
+VPIP_EXTERN int vpi_free_object(vpiHandle ref);
+VPIP_EXTERN int vpi_get_vlog_info(p_vpi_vlog_info vlog_info_p);
 
 
 /* This is the table of startup routines included in each module. */
-VPI_EXTERN void (*vlog_startup_routines[])();
+extern DLLEXPORT void (*vlog_startup_routines[])();
 
 #ifdef __cplusplus
 }
@@ -283,6 +275,9 @@ VPI_EXTERN void (*vlog_startup_routines[])();
 
 /*
  * $Log: vpi_user.h,v $
+ * Revision 1.22  2000/10/03 16:15:35  steve
+ *  Cleanup build of VPI modules under Cygwin. (Venkat)
+ *
  * Revision 1.21  2000/09/30 03:20:48  steve
  *  Cygwin port changes from Venkat
  *
diff --git a/vvm/Makefile.in b/vvm/Makefile.in
index 8d3306ba4..9c66a8d37 100644
--- a/vvm/Makefile.in
+++ b/vvm/Makefile.in
@@ -18,7 +18,7 @@
 #    59 Temple Place - Suite 330
 #    Boston, MA 02111-1307, USA
 #
-#ident "$Id: Makefile.in,v 1.33 2000/09/30 03:20:48 steve Exp $"
+#ident "$Id: Makefile.in,v 1.34 2000/10/03 16:15:35 steve Exp $"
 #
 #
 SHELL = /bin/sh
@@ -35,7 +35,7 @@ bindir = $(exec_prefix)/bin
 libdir = $(exec_prefix)/lib
 includedir = $(prefix)/include
 
-CC = @CC@ -I$(srcdir) -I$(srcdir)/../vpi -DBUILD_vvm
+CC = @CC@ -I$(srcdir) -I$(srcdir)/../vpi -D__build_vpip
 CXX = @CXX@ -I$(srcdir) -I$(srcdir)/../vpi
 INSTALL = @INSTALL@
 INSTALL_PROGRAM = @INSTALL_PROGRAM@
@@ -47,17 +47,28 @@ CFLAGS = @CFLAGS@
 LDFLAGS = @LDFLAGS@
 STRIP = @STRIP@
 
+O = vvm_add_sub.o vvm_bit.o vvm_calltf.o vvm_clshift.o vvm_compare.o \
+vvm_event.o vvm_ff.o vvm_force.o \
+vvm_func.o vvm_gates.o vvm_idiv.o vvm_imod.o vvm_mult.o vvm_mux.o \
+vvm_nexus.o vvm_pevent.o vvm_signal.o vvm_thread.o vvm_udp.o
+
+P = vpi_bit.o vpi_callback.o \
+vpi_const.o vpi_iter.o vpi_memory.o vpi_null.o \
+vpi_priv.o vpi_scope.o vpi_signal.o vpi_simulation.o vpi_systask.o vpi_time.o \
+vpi_mcd.o vpi_vlog_info.o
+
+
 
 ifeq (@CYGWIN@,yes)
 # In the DOS world, we need to split out the vpip object file.
 all: libvvm.a libvpip.a
 
-libvvm.a: $O libvpip.a
+libvvm.a: $O
 	rm -f $@
-	ar cvq $@ $O $P
+	ar cvq $@ $O
 
 libvpip.a vpip.dll: $P
-	$(CC) -shared -o libvpip.a -Wl,--enable-auto-image-base,--out-implib,libvpip.a -o vpip.dll $P
+	$(CC) -shared -Wl,--enable-auto-image-base,--out-implib,libvpip.a -o vpip.dll $P
 
 else
 
@@ -81,17 +92,6 @@ endif
 	$(CC) -Wall $(CPPFLAGS) $(CFLAGS) -MD -c $< -o $*.o
 	mv $*.d dep
 
-O = vvm_add_sub.o vvm_bit.o vvm_calltf.o vvm_clshift.o vvm_compare.o \
-vvm_event.o vvm_ff.o vvm_force.o \
-vvm_func.o vvm_gates.o vvm_idiv.o vvm_imod.o vvm_mult.o vvm_mux.o \
-vvm_nexus.o vvm_pevent.o vvm_signal.o vvm_thread.o vvm_udp.o
-
-P = vpi_bit.o vpi_callback.o \
-vpi_const.o vpi_iter.o vpi_memory.o vpi_null.o \
-vpi_priv.o vpi_scope.o vpi_signal.o vpi_simulation.o vpi_systask.o vpi_time.o \
-vpi_mcd.o vpi_vlog_info.o
-
-
 
 clean:
 	rm -f *.o dep/*.d
@@ -111,11 +111,11 @@ $(libdir)/libvvm.a: ./libvvm.a
 	$(INSTALL_DATA) ./libvvm.a $(libdir)/libvvm.a
 
 ifeq (@CYGWIN@,yes)
-install :: $(libdir)/libvvm.a \
+install :: $(libdir)/libvpip.a \
 	$(bindir)/vpip.dll
 
 $(libdir)/libvpip.a: ./libvpip.a
-	$(INSTALL_DATA) ./libvvm.a $(libdir)/libvpip.a
+	$(INSTALL_DATA) ./libvpip.a $(libdir)/libvpip.a
 
 $(bindir)/vpip.dll: ./vpip.dll
 	$(INSTALL_PROGRAM) ./vpip.dll $(bindir)/vpip.dll
diff --git a/vvm/vpi_priv.h b/vvm/vpi_priv.h
index 78ae3c04d..8a112eed5 100644
--- a/vvm/vpi_priv.h
+++ b/vvm/vpi_priv.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: vpi_priv.h,v 1.25 2000/09/30 03:20:48 steve Exp $"
+#ident "$Id: vpi_priv.h,v 1.26 2000/10/03 16:15:35 steve Exp $"
 #endif
 
 /*
@@ -107,13 +107,13 @@ typedef unsigned char vpip_bit_t;
 
       /* Take as input an array of bits, and return the resolved
 	 value. The result accounts for the strengths involved. */
-VVM_EXTERN vpip_bit_t vpip_pair_resolve(vpip_bit_t a, vpip_bit_t b);
-VVM_EXTERN vpip_bit_t vpip_bits_resolve(const vpip_bit_t*bits, unsigned nbits);
+VPIP_EXTERN vpip_bit_t vpip_pair_resolve(vpip_bit_t a, vpip_bit_t b);
+VPIP_EXTERN vpip_bit_t vpip_bits_resolve(const vpip_bit_t*bits, unsigned nbits);
 
 
-VVM_EXTERN void vpip_bits_get_value(const vpip_bit_t*bits, unsigned nbits,
+VPIP_EXTERN void vpip_bits_get_value(const vpip_bit_t*bits, unsigned nbits,
 				s_vpi_value*vp);
-VVM_EXTERN void vpip_bits_set_value(vpip_bit_t*bits, unsigned nbits,
+VPIP_EXTERN void vpip_bits_set_value(vpip_bit_t*bits, unsigned nbits,
 				s_vpi_value*vp);
 
 /*
@@ -203,7 +203,7 @@ struct __vpiNull {
       struct __vpiHandle base;
 };
 
-VVM_EXTERN struct __vpiNull vpip_null;
+VPIP_EXTERN struct __vpiNull vpip_null;
 
 /*
  * This type represents the handle to a Verilog scope. These include
@@ -219,7 +219,7 @@ struct __vpiScope {
       struct __vpiHandle**intern;
       unsigned nintern;
 };
-VVM_EXTERN void vpip_attach_to_scope(struct __vpiScope*scope, vpiHandle obj);
+VPIP_EXTERN void vpip_attach_to_scope(struct __vpiScope*scope, vpiHandle obj);
 
 
 /*
@@ -241,8 +241,8 @@ struct __vpiSignal {
 };
 
 
-VVM_EXTERN const struct __vpirt vpip_systask_rt;
-VVM_EXTERN const struct __vpirt vpip_sysfunc_rt;
+VPIP_EXTERN const struct __vpirt vpip_systask_rt;
+VPIP_EXTERN const struct __vpirt vpip_sysfunc_rt;
 struct __vpiSysTaskCall {
       struct __vpiHandle base;
 
@@ -293,35 +293,35 @@ struct __vpiNumberConst {
  * to allocate the memory for the handle. The result is the vpiHandle
  * of the constructed object.
  */
-VVM_EXTERN vpiHandle vpip_make_iterator(unsigned nargs, vpiHandle*args);
-VVM_EXTERN vpiHandle vpip_make_net(struct __vpiSignal*ref, const char*name,
+VPIP_EXTERN vpiHandle vpip_make_iterator(unsigned nargs, vpiHandle*args);
+VPIP_EXTERN vpiHandle vpip_make_net(struct __vpiSignal*ref, const char*name,
 			       vpip_bit_t*bits, unsigned nbits);
-VVM_EXTERN vpiHandle vpip_make_scope(struct __vpiScope*ref,
+VPIP_EXTERN vpiHandle vpip_make_scope(struct __vpiScope*ref,
 				 int type_code,
 				 const char*name);
-VVM_EXTERN vpiHandle vpip_make_string_const(struct __vpiStringConst*ref,
+VPIP_EXTERN vpiHandle vpip_make_string_const(struct __vpiStringConst*ref,
 					const char*val);
-VVM_EXTERN vpiHandle vpip_make_number_const(struct __vpiNumberConst*ref,
+VPIP_EXTERN vpiHandle vpip_make_number_const(struct __vpiNumberConst*ref,
 					const vpip_bit_t*bits,
 					unsigned nbits);
-VVM_EXTERN vpiHandle vpip_make_memory(struct __vpiMemory*ref, const char*name,
+VPIP_EXTERN vpiHandle vpip_make_memory(struct __vpiMemory*ref, const char*name,
 				  unsigned width, unsigned size);
-VVM_EXTERN vpiHandle vpip_make_reg(struct __vpiSignal*ref, const char*name,
+VPIP_EXTERN vpiHandle vpip_make_reg(struct __vpiSignal*ref, const char*name,
 			       vpip_bit_t*bits, unsigned nbits);
-VVM_EXTERN vpiHandle vpip_make_time_var(struct __vpiTimeVar*ref,
+VPIP_EXTERN vpiHandle vpip_make_time_var(struct __vpiTimeVar*ref,
 				    const char*val);
 
 /* Use this function to call a registered task. */
-VVM_EXTERN void vpip_calltask(const char*name, unsigned nparms, vpiHandle*parms);
+VPIP_EXTERN void vpip_calltask(const char*name, unsigned nparms, vpiHandle*parms);
 
 /*
  * This calls a system function with a given name. The return value is
  * taken by the res[] array.
  */
-VVM_EXTERN void vpip_callfunc(const char*name, unsigned nres, vpip_bit_t*res,
+VPIP_EXTERN void vpip_callfunc(const char*name, unsigned nres, vpip_bit_t*res,
 			  unsigned nparms, vpiHandle*parms);
 
-VVM_EXTERN void vpip_run_value_changes(struct __vpiSignal*sig);
+VPIP_EXTERN void vpip_run_value_changes(struct __vpiSignal*sig);
 
 /*
  * The simulation object holds the current state of the
@@ -347,13 +347,13 @@ struct vpip_simulation {
       short time_precision;
 };
 
-VVM_EXTERN struct vpip_simulation vpip_simulation_obj;
+VPIP_EXTERN struct vpip_simulation vpip_simulation_obj;
 
-VVM_EXTERN void vpip_set_vlog_info(int argc, char**argv);
-VVM_EXTERN void vpip_init_simulation();
-VVM_EXTERN void vpip_time_scale(int precision);
-VVM_EXTERN void vpip_simulation_run();
-VVM_EXTERN void vpi_mcd_init(void);
+VPIP_EXTERN void vpip_set_vlog_info(int argc, char**argv);
+VPIP_EXTERN void vpip_init_simulation();
+VPIP_EXTERN void vpip_time_scale(int precision);
+VPIP_EXTERN void vpip_simulation_run();
+VPIP_EXTERN void vpi_mcd_init(void);
 
 /*
  * Schedule an event to be run sometime in the future. The d parmater
@@ -364,22 +364,22 @@ VVM_EXTERN void vpi_mcd_init(void);
  * The return value from the insert method is a cookie that can be
  * used to manipulate the event before it is executed.
  */
-VVM_EXTERN struct vpip_event* vpip_sim_insert_event(unsigned long d,
+VPIP_EXTERN struct vpip_event* vpip_sim_insert_event(unsigned long d,
 						void*user_data,
 						void (*sim_fun)(void*),
 						int nonblock_flag);
-VVM_EXTERN void vpip_sim_cancel_event(struct vpip_event*cookie);
+VPIP_EXTERN void vpip_sim_cancel_event(struct vpip_event*cookie);
 
 /*
  * This function returns a handle to the vpiTimeVar that is th main
  * simulation time clock.
  */
-VVM_EXTERN vpiHandle vpip_sim_time();
+VPIP_EXTERN vpiHandle vpip_sim_time();
 
 /*
  * Return true if the going_flag is false.
  */
-VVM_EXTERN int vpip_finished();
+VPIP_EXTERN int vpip_finished();
 
 
 #ifdef __cplusplus
@@ -388,6 +388,9 @@ VVM_EXTERN int vpip_finished();
 
 /*
  * $Log: vpi_priv.h,v $
+ * Revision 1.26  2000/10/03 16:15:35  steve
+ *  Cleanup build of VPI modules under Cygwin. (Venkat)
+ *
  * Revision 1.25  2000/09/30 03:20:48  steve
  *  Cygwin port changes from Venkat
  *