diff -rpu au88x0_orig/au88x0.h au88x0/au88x0.h
--- au88x0_orig/au88x0.h	2005-09-14 20:52:57.000000000 +0300
+++ au88x0/au88x0.h	2005-09-14 20:54:47.000000000 +0300
@@ -79,6 +79,9 @@
 #define VORTEX_RESOURCE_A3D	0x00000004
 #define VORTEX_RESOURCE_LAST	0x00000005
 
+/* codec io related */
+#define VORTEX_CODEC_ID_SHIFT	30 /* unknown: may be 24-31 (or irrelevat) */
+
 /* Check for SDAC bit in "Extended audio ID" AC97 register */
 //#define VORTEX_IS_QUAD(x) (((x)->codec == NULL) ?  0 : ((x)->codec->ext_id&0x80))
 #define VORTEX_IS_QUAD(x) ((x)->isquad)
diff -rpu au88x0_orig/au88x0_core.c au88x0/au88x0_core.c
--- au88x0_orig/au88x0_core.c	2005-09-13 20:00:50.000000000 +0300
+++ au88x0/au88x0_core.c	2005-09-14 20:51:03.000000000 +0300
@@ -2537,7 +2537,8 @@ vortex_codec_write(ac97_t * codec, unsig
 	hwwrite(card->mmio, VORTEX_CODEC_IO,
 		((addr << VORTEX_CODEC_ADDSHIFT) & VORTEX_CODEC_ADDMASK) |
 		((data << VORTEX_CODEC_DATSHIFT) & VORTEX_CODEC_DATMASK) |
-		VORTEX_CODEC_WRITE);
+		VORTEX_CODEC_WRITE |
+		(codec->num << VORTEX_CODEC_ID_SHIFT) );
 
 	/* Flush Caches. */
 	hwread(card->mmio, VORTEX_CODEC_IO);
@@ -2559,7 +2560,8 @@ static unsigned short vortex_codec_read(
 		}
 	}
 	/* set up read address */
-	read_addr = ((addr << VORTEX_CODEC_ADDSHIFT) & VORTEX_CODEC_ADDMASK);
+	read_addr = ((addr << VORTEX_CODEC_ADDSHIFT) & VORTEX_CODEC_ADDMASK) |
+		(codec->num << VORTEX_CODEC_ID_SHIFT) ;
 	hwwrite(card->mmio, VORTEX_CODEC_IO, read_addr);
 
 	/* wait for address */