it works for me

Reference: /n/sources/patch/applied/ide5513
Date: Wed Nov  3 14:10:55 CET 2004

--- /sys/src/9/pc/sdata.c	Wed Nov  3 14:10:56 2004
+++ /sys/src/9/pc/sdata.c	Wed Nov  3 14:10:55 2004
@@ -1903,6 +1903,7 @@
 			 * address for the registers (0x50?).
 			 */
 			break;
+		case (0x5513<<16)|0x1039:	/* SiS 962 */
 		case (0x0646<<16)|0x1095:	/* CMD 646 */
 		case (0x0571<<16)|0x1106:	/* VIA 82C686 */
 		case (0x0211<<16)|0x1166:	/* ServerWorks IB6566 */