diff --git a/src/video/vid_svga.c b/src/video/vid_svga.c
index 2fed471f9..4b80a0eed 100644
--- a/src/video/vid_svga.c
+++ b/src/video/vid_svga.c
@@ -956,14 +956,18 @@ svga_recalctimings(svga_t *svga)
         svga->hdisp -= (svga->hblank_sub * svga->dots_per_clock);
 
         svga->left_overscan = svga->x_add = (svga->htotal - adj_dot - 1) * svga->dots_per_clock;
-        svga->monitor->mon_overscan_x = svga->x_add + (svga->hblankstart * svga->dots_per_clock) - hd;
+        svga->monitor->mon_overscan_x = svga->x_add + (svga->hblankstart * svga->dots_per_clock) - hd + svga->dots_per_clock;
+        /* Compensate for the HDISP code above. */
+        if (svga->crtc[1] & 1)
+            svga->monitor->mon_overscan_x++;
 
         if ((svga->hdisp >= 2048) || (svga->left_overscan < 0)) {
             svga->left_overscan = svga->x_add = 0;
             svga->monitor->mon_overscan_x = 0;
         }
 
-        svga->y_add = svga->vtotal - vblankend + 1;
+        /* - 1 because + 1 but also - 2 to compensate for the + 2 added to vtotal above. */
+        svga->y_add = svga->vtotal - vblankend - 1;
         svga->monitor->mon_overscan_y = svga->y_add + abs(svga->vblankstart - svga->dispend);
 
         if ((svga->dispend >= 2048) || (svga->y_add < 0)) {
diff --git a/src/video/vid_tandy.c b/src/video/vid_tandy.c
index 312527a35..0609ca378 100644
--- a/src/video/vid_tandy.c
+++ b/src/video/vid_tandy.c
@@ -483,7 +483,7 @@ vid_poll(void *priv)
                     vid->memaddr++;
                     if (vid->scanline & 8) {
                         for (c = 0; c < 8; c++)
-                            buffer32->line[vid->displine << 1][(x << 4) + (c << 1) + 8] = buffer32->line[vid->displine << 1][(x << 4) + (c << 1) + 1 + 8] = cols[0];
+                            buffer32->line[vid->displine << 1][(x << 4) + (c << 1) + 8] = buffer32->line[(vid->displine << 1) + 1][(x << 4) + (c << 1) + 8] = buffer32->line[vid->displine << 1][(x << 4) + (c << 1) + 1 + 8] = buffer32->line[(vid->displine << 1) + 1][(x << 4) + (c << 1) + 1 + 8] = cols[0];
                     } else {
                         for (c = 0; c < 8; c++) {
                             if (vid->scanline == 8) {
@@ -824,4 +824,4 @@ const device_t tandy_1000sl_video_device = {
     .speed_changed = tandy_vid_speed_changed,
     .force_redraw  = NULL,
     .config        = NULL
-};
\ No newline at end of file
+};
diff --git a/src/video/vid_voodoo.c b/src/video/vid_voodoo.c
index e45f112ed..57ddbf64d 100644
--- a/src/video/vid_voodoo.c
+++ b/src/video/vid_voodoo.c
@@ -530,6 +530,7 @@ voodoo_writel(uint32_t addr, uint32_t val, void *priv)
                         voodoo_recalc(voodoo);
                         voodoo->front_offset = voodoo->params.front_offset;
                     }
+                    svga_recalctimings(voodoo->svga);
                 }
                 break;
             case SST_fbiInit1: