--- include/grx20.h.orig	2011-11-18 19:44:15.000000000 +0100
+++ include/grx20.h	2011-11-18 19:45:49.000000000 +0100
@@ -1636,6 +1636,7 @@
 int  GrMatchString(const char *pattern,const char *strg);
 void GrSetWindowTitle(char *title);
 void GrSleep(int msec);
+void GrFlush(void);
 
 /* ================================================================== */
 /*                        TIFF ADDON FUNCTIONS                        */
--- src/misc/x11misc.c.orig	2001-03-23 05:33:20.000000000 +0100
+++ src/misc/x11misc.c	2011-11-18 19:00:21.000000000 +0100
@@ -31,3 +31,8 @@
   usleep( msec*1000L );
 }
 
+void GrFlush( void )
+{
+  _GrUpdateInputs();
+  XFlush(_XGrDisplay);
+}
+
--- src/misc/w32misc.c.orig	2001-03-23 05:33:20.000000000 +0100
+++ src/misc/w32misc.c	2011-11-18 18:48:56.000000000 +0100
@@ -29,3 +29,7 @@
   Sleep( msec );
 }
 
+void GrFlush( void)
+{
+}
+
--- src/misc/sdlmisc.c.orig	2007-03-19 11:34:16.000000000 +0100
+++ src/misc/sdlmisc.c	2011-11-18 18:50:14.000000000 +0100
@@ -28,3 +28,7 @@
 {
 	SDL_Delay(msec);
 }
+
+void GrFlush( void)
+{
+}
--- src/misc/lnxmisc.c.orig	2001-03-23 05:07:20.000000000 +0100
+++ src/misc/lnxmisc.c	2011-11-18 18:50:33.000000000 +0100
@@ -28,3 +28,6 @@
   usleep( msec*1000L );
 }
 
+void GrFlush( void)
+{
+}
--- src/misc/dosmisc.c.orig	2001-03-23 05:05:36.000000000 +0100
+++ src/misc/dosmisc.c	2011-11-18 18:50:52.000000000 +0100
@@ -28,3 +28,6 @@
   delay( msec );
 }
 
+void GrFlush( void)
+{
+}
--- pascal/grx.pas.orig	2011-11-18 19:48:43.000000000 +0100
+++ pascal/grx.pas	2011-11-18 19:52:53.000000000 +0100
@@ -1388,6 +1388,7 @@
 function  GrMatchString (Pattern, Strg: CString): CInteger; asmname 'GrMatchString';
 procedure GrSetWindowTitle (Title: CString); asmname 'GrSetWindowTitle';
 procedure GrSleep (MSec: CInteger); asmname 'GrSleep';
+procedure GrFlush; asmname 'GrFlush';
 
 { ==================================================================
                             PNM FUNCTIONS
--- pascal/bgi/graph.pas.orig	2011-11-18 19:54:45.000000000 +0100
+++ pascal/bgi/graph.pas	2011-11-18 18:57:27.000000000 +0100
@@ -488,6 +488,10 @@
 function ReadKey: Char; asmname 'getch';
 {$endif}
 
+{flush the graphics: useful only in X windows when switching 
+ between graphics and console windows open simultaneously}
+procedure GrFlush; asmname 'GrFlush';
+
 implementation
 
 procedure dg(var GraphDriver, GraphMode: CInteger); asmname 'detectgraph';