MESS

Index: src/emu/video/pc_vga.c
===================================================================
--- src/emu/video/pc_vga.c      (revision 18335)
+++ src/emu/video/pc_vga.c      (working copy)
@@ -414,7 +414,7 @@
        int height = vga.crtc.maximum_scan_line * (vga.crtc.scan_doubling + 1);
        int yi;
        int xi;
-       int pel_shift = 0;//vga.attribute.pel_shift; /* TODO: timing bug with this */
+       int pel_shift = vga.attribute.pel_shift + ((vga.crtc.preset_row_scan >> 5) & 3);//vga.attribute.pel_shift; /* TODO: timing bug with this */

        /* line compare is screen sensitive */
        mask_comp = 0x3ff; //| (LINES & 0x300);