# HG changeset patch
# User TomW
# Date 1404679228 -3600
# Node ID bd2ab065dd811da193c2ef8e999c156b3051d14e
# Parent  9834054948fcbfdd62cd8c89a248b362938c97d4
Port 0x3da diagnostic bits now held static during blanking, fixes DOS 6.2/V hang.

diff -r 9834054948fc -r bd2ab065dd81 src/vid_svga.c
--- a/src/vid_svga.c	Sun Jul 06 12:45:35 2014 +0100
+++ b/src/vid_svga.c	Sun Jul 06 21:40:28 2014 +0100
@@ -229,7 +229,10 @@
                 return svga->gdcreg[svga->gdcaddr & 0xf];
                 case 0x3DA:
                 svga->attrff = 0;
-                svga->cgastat ^= 0x30;
+                if (svga->cgastat & 0x01)
+                        svga->cgastat &= ~0x30;
+                else
+                        svga->cgastat ^= 0x30;
                 return svga->cgastat;
         }
 //        printf("Bad EGA read %04X %04X:%04X\n",addr,cs>>4,pc);