diff -Nru xterm-223.orig/charproc.c xterm-223/charproc.c
--- xterm-223.orig/charproc.c	2006-11-28 20:45:37.000000000 +0000
+++ xterm-223/charproc.c	2006-12-26 12:43:06.000000000 +0000
@@ -4591,6 +4591,22 @@
 			 XGetWMName(screen->display, VShellWindow, &text));
 	break;
 
+    case 23:  /* report font width/height */
+	    reply.a_type = CSI;
+	    reply.a_pintro = 0;
+	    reply.a_nparam = 3;
+	    reply.a_param[0] = 4;
+	    /*FIXME: find if dtterm uses
+	     *    win_attrs.height or Height
+	     *      win_attrs.width  or Width
+	     */
+	    reply.a_param[1] = FontWidth(&term->screen);
+	    reply.a_param[2] = FontHeight(&term->screen);
+	    reply.a_inters = 0;
+	    reply.a_final = 't';
+	    unparseseq(xw, &reply);
+	    break;
+	    
     default:			/* DECSLPP (24, 25, 36, 48, 72, 144) */
 	if (param[0] >= 24)
 	    RequestResize(xw, param[0], -1, True);