diff -uNr trident.orig/trident_driver.c trident/trident_driver.c
--- trident.orig/trident_driver.c	2005-11-14 10:47:27.704414000 +0100
+++ trident/trident_driver.c	2005-11-26 16:49:10.131971000 +0100
@@ -2281,7 +2281,7 @@
     clockRanges->maxClock = pTrident->MaxClock;
     clockRanges->clockIndex = -1;		/* programmable */
     clockRanges->interlaceAllowed = TRUE;
-    clockRanges->doubleScanAllowed = FALSE;	/* XXX check this */
+    clockRanges->doubleScanAllowed = TRUE;
 
     /*
      * xf86ValidateModes will check that the mode HTotal and VTotal values
diff -uNr trident.orig/trident_video.c trident/trident_video.c
--- trident.orig/trident_video.c	2005-11-14 10:47:27.824421000 +0100
+++ trident/trident_video.c	2005-11-26 17:14:09.323119000 +0100
@@ -878,6 +878,13 @@
 
     offset += top * dstPitch;
 
+    /* Fix video position when using doublescan */
+    if(pScrn->currentMode->Flags & V_DBLSCAN) {
+	    dstBox.y1 <<= 1;
+	    dstBox.y2 <<= 1;
+	    drw_h <<= 1;
+    }
+    
     tridentFixFrame(pScrn,&pPriv->fixFrame);
     TRIDENTDisplayVideo(pScrn, id, offset, width, height, dstPitch,
 	     x1, y1, x2, y2, &dstBox, src_w, src_h, drw_w, drw_h);