diff --git a/sound/pci/azt3328.h b/sound/pci/azt3328.h
index 7e0e791..f489bda 100644
--- a/sound/pci/azt3328.h
+++ b/sound/pci/azt3328.h
@@ -1,19 +1,17 @@
-#ifndef __SOUND_AZF3328_H
-#define __SOUND_AZF3328_H
+#ifndef __SOUND_AZT3328_H
+#define __SOUND_AZT3328_H
 
-/* type argument to use for the I/O functions */
-#define WORD_VALUE      0x1000
-#define DWORD_VALUE     0x2000
-#define BYTE_VALUE      0x4000
+/* "PU" == "power-up value", as tested on PCI168 PCI rev. 10 */
 
 /*** main I/O area port indices ***/
 /* (only 0x70 of 0x80 bytes saved/restored by Windows driver) */
-/* the driver initialisation suggests a layout of 3 main areas:
- * from 0x00 (playback), from 0x20 (recording) and from 0x40 (maybe DirectX
- * timer ???). and probably another area from 0x60 to 0x6f
- * (IRQ management, power management etc. ???). */
-/* playback area */
-#define IDX_IO_PLAY_FLAGS       0x00
+/* the driver initialisation suggests a layout of 4 main areas:
+ * from 0x00 (playback), from 0x20 (recording) and from 0x40 (maybe MPU401??).
+ * And another area from 0x60 to 0x6f (DirectX timer, IRQ management,
+ * power management etc.???). */
+
+/** playback area **/
+#define IDX_IO_PLAY_FLAGS       0x00 /* PU:0x0000 */
      /* able to reactivate output after output muting due to 8/16bit
       * output change, just like 0x0002.
       * 0x0001 is the only bit that's able to start the DMA counter */
@@ -29,7 +27,7 @@
   #define DMA_EPILOGUE_SOMETHING	0x0010
   #define DMA_SOMETHING_ELSE		0x0020 /* ??? */
   #define SOMETHING_UNMODIFIABLE	0xffc0 /* unused ? not modifiable */
-#define IDX_IO_PLAY_IRQMASK     0x02
+#define IDX_IO_PLAY_IRQTYPE     0x02 /* PU:0x0001 */
   /* write back to flags in case flags are set, in order to ACK IRQ in handler
    * (bit 1 of port 0x64 indicates interrupt for one of these three types)
    * sometimes in this case it just writes 0xffff to globally ACK all IRQs
@@ -41,36 +39,39 @@
   #define IRQMASK_SOME_STATUS_1		0x0008 /* \ related bits */
   #define IRQMASK_SOME_STATUS_2		0x0010 /* / (checked together in loop) */
   #define IRQMASK_UNMODIFIABLE		0xffe0 /* unused ? not modifiable */
-#define IDX_IO_PLAY_DMA_START_1 0x04 /* start address of 1st DMA play area */
-#define IDX_IO_PLAY_DMA_START_2 0x08 /* start address of 2nd DMA play area */
-#define IDX_IO_PLAY_DMA_LEN_1   0x0c /* length of 1st DMA play area */
-#define IDX_IO_PLAY_DMA_LEN_2   0x0e /* length of 2nd DMA play area */
-#define IDX_IO_PLAY_DMA_CURRPOS 0x10 /* current DMA position  */
-#define IDX_IO_PLAY_DMA_CURROFS	0x14 /* offset within current DMA play area */
-#define IDX_IO_PLAY_SOUNDFORMAT 0x16
+#define IDX_IO_PLAY_DMA_START_1 0x04 /* start address of 1st DMA play area, PU:0x00000000 */
+#define IDX_IO_PLAY_DMA_START_2 0x08 /* start address of 2nd DMA play area, PU:0x00000000 */
+#define IDX_IO_PLAY_DMA_LEN_1   0x0c /* length of 1st DMA play area, PU:0x0000 */
+#define IDX_IO_PLAY_DMA_LEN_2   0x0e /* length of 2nd DMA play area, PU:0x0000 */
+#define IDX_IO_PLAY_DMA_CURRPOS 0x10 /* current DMA position, PU:0x00000000 */
+#define IDX_IO_PLAY_DMA_CURROFS	0x14 /* offset within current DMA play area, PU:0x0000 */
+#define IDX_IO_PLAY_SOUNDFORMAT 0x16 /* PU:0x0010 */
   /* all unspecified bits can't be modified */
   #define SOUNDFORMAT_FREQUENCY_MASK	0x000f
+  #define SOUNDFORMAT_XTAL1		0x00
+  #define SOUNDFORMAT_XTAL2		0x01
     /* all _SUSPECTED_ values are not used by Windows drivers, so we don't
      * have any hard facts, only rough measurements */
-    #define SOUNDFORMAT_FREQ_SUSPECTED_4000	0x0c
-    #define SOUNDFORMAT_FREQ_SUSPECTED_4800	0x0a
-    #define SOUNDFORMAT_FREQ_5510		0x0d
-    #define SOUNDFORMAT_FREQ_6620		0x0b
-    #define SOUNDFORMAT_FREQ_8000		0x00 /* also 0x0e ? */
-    #define SOUNDFORMAT_FREQ_9600		0x08
-    #define SOUNDFORMAT_FREQ_SUSPECTED_12000	0x09
-    #define SOUNDFORMAT_FREQ_11025		0x01 /* also 0x0f ? */
-    #define SOUNDFORMAT_FREQ_16000		0x02
-    #define SOUNDFORMAT_FREQ_22050		0x03
-    #define SOUNDFORMAT_FREQ_32000		0x04
-    #define SOUNDFORMAT_FREQ_44100		0x05
-    #define SOUNDFORMAT_FREQ_48000		0x06
-    #define SOUNDFORMAT_FREQ_SUSPECTED_64000	0x07
+    #define SOUNDFORMAT_FREQ_SUSPECTED_4000	0x0c | SOUNDFORMAT_XTAL1
+    #define SOUNDFORMAT_FREQ_SUSPECTED_4800	0x0a | SOUNDFORMAT_XTAL1
+    #define SOUNDFORMAT_FREQ_5510		0x0c | SOUNDFORMAT_XTAL2
+    #define SOUNDFORMAT_FREQ_6620		0x0a | SOUNDFORMAT_XTAL2
+    #define SOUNDFORMAT_FREQ_8000		0x00 | SOUNDFORMAT_XTAL1 /* also 0x0e | SOUNDFORMAT_XTAL1? */
+    #define SOUNDFORMAT_FREQ_9600		0x08 | SOUNDFORMAT_XTAL1
+    #define SOUNDFORMAT_FREQ_11025		0x00 | SOUNDFORMAT_XTAL2 /* also 0x0e | SOUNDFORMAT_XTAL2? */
+    #define SOUNDFORMAT_FREQ_SUSPECTED_13240	0x08 | SOUNDFORMAT_XTAL2 /* seems to be 6620 *2 */
+    #define SOUNDFORMAT_FREQ_16000		0x02 | SOUNDFORMAT_XTAL1
+    #define SOUNDFORMAT_FREQ_22050		0x02 | SOUNDFORMAT_XTAL2
+    #define SOUNDFORMAT_FREQ_32000		0x04 | SOUNDFORMAT_XTAL1
+    #define SOUNDFORMAT_FREQ_44100		0x04 | SOUNDFORMAT_XTAL2
+    #define SOUNDFORMAT_FREQ_48000		0x06 | SOUNDFORMAT_XTAL1
+    #define SOUNDFORMAT_FREQ_SUSPECTED_66200	0x06 | SOUNDFORMAT_XTAL2 /* 66200 (13240 * 5); 64000 may have been nicer :-\ */
   #define SOUNDFORMAT_FLAG_16BIT	0x0010
   #define SOUNDFORMAT_FLAG_2CHANNELS	0x0020
-/* recording area (see also: playback bit flag definitions) */
-#define IDX_IO_REC_FLAGS	0x20 /* ?? */
-#define IDX_IO_REC_IRQMASK	0x22 /* ?? */
+
+/** recording area (see also: playback bit flag definitions) **/
+#define IDX_IO_REC_FLAGS	0x20 /* ??, PU:0x0000 */
+#define IDX_IO_REC_IRQTYPE	0x22 /* ??, PU:0x0000 */
   #define IRQ_REC_SOMETHING		0x0001 /* something & ACK */
   #define IRQ_FINISHED_RECBUF_1		0x0002 /* 1st dmabuf finished & ACK */
   #define IRQ_FINISHED_RECBUF_2		0x0004 /* 2nd dmabuf finished & ACK */
@@ -78,39 +79,47 @@
    * but OTOH they are most likely at port 0x22 instead */
   #define IRQMASK_SOME_STATUS_1		0x0008 /* \ related bits */
   #define IRQMASK_SOME_STATUS_2		0x0010 /* / (checked together in loop) */
-#define IDX_IO_REC_DMA_START_1  0x24
-#define IDX_IO_REC_DMA_START_2  0x28
-#define IDX_IO_REC_DMA_LEN_1    0x2c
-#define IDX_IO_REC_DMA_LEN_2    0x2e
-#define IDX_IO_REC_DMA_CURRPOS  0x30
-#define IDX_IO_REC_DMA_CURROFS  0x34
-#define IDX_IO_REC_SOUNDFORMAT  0x36
-/* some third area ? (after playback and recording) */
-#define IDX_IO_SOMETHING_FLAGS	0x40 /* gets set to 0x34 just like port 0x0 and 0x20 on card init */
+#define IDX_IO_REC_DMA_START_1  0x24 /* PU:0x00000000 */
+#define IDX_IO_REC_DMA_START_2  0x28 /* PU:0x00000000 */
+#define IDX_IO_REC_DMA_LEN_1    0x2c /* PU:0x0000 */
+#define IDX_IO_REC_DMA_LEN_2    0x2e /* PU:0x0000 */
+#define IDX_IO_REC_DMA_CURRPOS  0x30 /* PU:0x00000000 */
+#define IDX_IO_REC_DMA_CURROFS  0x34 /* PU:0x00000000 */
+#define IDX_IO_REC_SOUNDFORMAT  0x36 /* PU:0x0000 */
+
+/** hmm, what is this I/O area for? MPU401?? (after playback, recording, ???, timer) **/
+#define IDX_IO_SOMETHING_FLAGS	0x40 /* gets set to 0x34 just like port 0x0 and 0x20 on card init, PU:0x0000 */
 /* general */
-#define IDX_IO_60H		0x60 /* writing 0xffff returns 0xffff */
-#define IDX_IO_62H		0x62 /* writing to WORD 0x0062 can hang the box ! --> responsible for IRQ management as a whole ?? */
-#define IDX_IO_IRQ63H		0x63 /* FIXME !! */
-  #define IO_IRQ63H_SOMETHING		0x04 /* being set in IRQ handler in case port 0x00 had 0x0020 set upon IRQ handler */
+#define IDX_IO_42H		0x42 /* PU:0x0001 */
+
+/** DirectX timer, main interrupt area (FIXME: and something else?) **/ 
+#define IDX_IO_TIMER_VALUE	0x60 /* found this timer area by pure luck :-) */
+  #define TIMER_VALUE_MASK		0x000fffffUL /* timer countdown value; triggers IRQ when timer is finished */
+  #define TIMER_ENABLE_COUNTDOWN	0x01000000UL /* activate the timer countdown */
+  #define TIMER_ENABLE_IRQ		0x02000000UL /* trigger timer IRQ on zero transition */
+  #define TIMER_ACK_IRQ			0x04000000UL /* being set in IRQ handler in case port 0x00 (hmm, not port 0x64!?!?) had 0x0020 set upon IRQ handler */
 #define IDX_IO_IRQSTATUS        0x64
   #define IRQ_PLAYBACK			0x0001
   #define IRQ_RECORDING			0x0002
   #define IRQ_MPU401			0x0010
-  #define IRQ_SOMEIRQ			0x0020 /* ???? */
-  #define IRQ_WHO_KNOWS_UNUSED		0x00e0 /* probably unused */
+  #define IRQ_TIMER			0x0020 /* DirectX timer */
+  #define IRQ_UNKNOWN1			0x0040 /* probably unused */
+  #define IRQ_UNKNOWN2			0x0080 /* probably unused */
 #define IDX_IO_66H		0x66    /* writing 0xffff returns 0x0000 */
-#define IDX_IO_SOME_VALUE	0x68	/* this is always set to 0x3ff, and writable; maybe some buffer limit, but I couldn't find out more */
-#define IDX_IO_6AH		0x6A	/* this WORD can be set to have bits 0x0028 activated; actually inhibits PCM playback !!! maybe power management ?? */
-#define IDX_IO_6CH		0x6C	/* this WORD can have all its bits activated ? */
+#define IDX_IO_SOME_VALUE	0x68	/* this is set to e.g. 0x3ff or 0x300, and writable; maybe some buffer limit, but I couldn't find out more, PU:0x00ff */
+#define IDX_IO_6AH		0x6A	/* this WORD can be set to have bits 0x0028 activated; actually inhibits PCM playback!!! maybe power management?? */
+#define IDX_IO_6CH		0x6C
 #define IDX_IO_6EH		0x6E	/* writing 0xffff returns 0x83fe */
 /* further I/O indices not saved/restored, so probably not used */
 
+
 /*** I/O 2 area port indices ***/
 /* (only 0x06 of 0x08 bytes saved/restored by Windows driver) */ 
 #define IDX_IO2_LEGACY_ADDR	0x04
-  #define LEGACY_SOMETHING		0x01 /* OPL3 ?? */
+  #define LEGACY_SOMETHING		0x01 /* OPL3?? */
   #define LEGACY_JOY			0x08
 
+
 /*** mixer I/O area port indices ***/
 /* (only 0x22 of 0x40 bytes saved/restored by Windows driver)
  * generally spoken: AC97 register index = AZF3328 mixer reg index + 2
@@ -148,18 +157,18 @@
   /* unlisted bits are unmodifiable */
   #define MIXER_ADVCTL1_3DWIDTH_MASK	0x000e
   #define MIXER_ADVCTL1_HIFI3D_MASK	0x0300
-#define IDX_MIXER_ADVCTL2       0x20 /* resembles AC97_GENERAL_PURPOSE reg ! */
+#define IDX_MIXER_ADVCTL2       0x20 /* resembles AC97_GENERAL_PURPOSE reg! */
   /* unlisted bits are unmodifiable */
-  #define MIXER_ADVCTL2_BIT7		0x0080 /* WaveOut 3D Bypass ? mutes WaveOut at LineOut */
-  #define MIXER_ADVCTL2_BIT8		0x0100 /* is this Modem Out Select ? */
-  #define MIXER_ADVCTL2_BIT9		0x0200 /* Mono Select Source ? */
-  #define MIXER_ADVCTL2_BIT13		0x2000 /* 3D enable ? */
+  #define MIXER_ADVCTL2_BIT7		0x0080 /* WaveOut 3D Bypass? mutes WaveOut at LineOut */
+  #define MIXER_ADVCTL2_BIT8		0x0100 /* is this Modem Out Select? */
+  #define MIXER_ADVCTL2_BIT9		0x0200 /* Mono Select Source? */
+  #define MIXER_ADVCTL2_BIT13		0x2000 /* 3D enable? */
   #define MIXER_ADVCTL2_BIT15		0x8000 /* unknown */
   
-#define IDX_MIXER_SOMETHING30H	0x30 /* used, but unknown ??? */
+#define IDX_MIXER_SOMETHING30H	0x30 /* used, but unknown??? */
 
 /* driver internal flags */
 #define SET_CHAN_LEFT	1
 #define SET_CHAN_RIGHT	2
 
-#endif /* __SOUND_AZF3328_H  */
+#endif /* __SOUND_AZT3328_H  */