HW cursor position fixing

Author: Cacodemon345

src/video/vid_c&t_69000.c

@@ -1533,8 +1533,10 @@ chips_69000_write_ext_reg(chips_69000_t* chips, uint8_t val)
         case 0xA6:
             chips->ext_regs[chips->ext_index] = val;
             chips->svga.hwcursor.y = val | (chips->ext_regs[0xA7] & 7) << 8;
-            if (chips->ext_regs[0xA7] & 0x80)
-                chips->svga.hwcursor.y = -chips->svga.hwcursor.y;
+            if (chips->ext_regs[0xA7] & 0x80) {
+                chips->svga.hwcursor.yoff = chips->svga.hwcursor.y;
+                chips->svga.hwcursor.y = 0;
+            }
             break;
         case 0xA7:
             chips->ext_regs[chips->ext_index] = val;