Index: src/main.cc
===================================================================
--- src/main.cc	(revision 76)
+++ src/main.cc	(working copy)
@@ -52,6 +52,7 @@
     OPT_CELL_WIDTH,
     OPT_FONT,
     OPT_FONT_SIZE,
+    OPT_GRID,
     OPT_HELP,
     OPT_LINE_WIDTH,
     OPT_OUTPUT,
@@ -67,6 +68,7 @@
   {"cell-width", required_argument, NULL, OPT_CELL_WIDTH},
   {"font", required_argument, NULL, OPT_FONT},
   {"font-size", required_argument, NULL, OPT_FONT_SIZE},
+  {"grid", no_argument, NULL, OPT_GRID},
   {"help", no_argument, NULL, OPT_HELP},
   {"line-width", required_argument, NULL, OPT_LINE_WIDTH},
   {"output", required_argument, NULL, OPT_OUTPUT},
@@ -110,6 +112,10 @@
     case OPT_FONT_SIZE:
       timing::vFontPointsize = atoi (optarg);
       break;    
+    case 'g':
+    case OPT_GRID:
+      timing::draw_grid = true;
+      break;    
     case 'h':
     case OPT_HELP:
       usage ();
@@ -279,6 +285,9 @@
        << "-l" << endl
        << "--line-width" << endl
        << "    Line width (pixels) [3]." << endl
+       << "-g" << endl
+       << "--grid" << endl
+       << "    Turn on grid." << endl
        << endl
        << "Consult the drawtiming(1) man page for details." << endl;
 }
Index: src/timing.cc
===================================================================
--- src/timing.cc	(revision 76)
+++ src/timing.cc	(working copy)
@@ -18,6 +18,7 @@
 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
 #include "timing.h"
+#include <string.h>
 #include <map>
 #include <fstream>
 using namespace std;
@@ -29,6 +30,7 @@
 int timing::vCellHt = 32;
 int timing::vCellW = 64;
 string timing::vFont = "Helvetica";
+bool timing::draw_grid = false;
 
 static int vCellHsep, vCellH, vCellHtxt, vCellHdel, vCellHtdel, vCellWtsep,
             vCellWrm;
@@ -611,6 +613,14 @@
     y += vCellHt + vCellHdel * sig.maxdelays;
   }
 
+  if(timing::draw_grid) {
+    int x = labelWidth + vCellWtsep;
+    for(int j; j <= d.maxlen; j++) {
+      gc.line(x,0,x,y);
+      x += vCellW;
+    }
+  }
+
   // draw the smooth arrows indicating the triggers for signal changes
   for (list<depdata>::const_iterator i = d.dependencies.begin ();
        i != d.dependencies.end (); ++ i)
Index: src/timing.h
===================================================================
--- src/timing.h	(revision 76)
+++ src/timing.h	(working copy)
@@ -46,6 +46,7 @@
 
   extern int vFontPointsize, vLineWidth, vCellHt, vCellW;
   extern std::string vFont;
+  extern bool draw_grid;
 
   class exception : public std::exception {
   };